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  Subjects -> MANUFACTURING AND TECHNOLOGY (Total: 281 journals)
    - CERAMICS, GLASS AND POTTERY (26 journals)
    - MACHINERY (33 journals)
    - MANUFACTURING AND TECHNOLOGY (171 journals)
    - METROLOGY AND STANDARDIZATION (3 journals)
    - PACKAGING (15 journals)
    - PAINTS AND PROTECTIVE COATINGS (5 journals)
    - PLASTICS (27 journals)
    - RUBBER (1 journals)

MACHINERY (33 journals)

Acta Mechanica Solida Sinica     Full-text available via subscription   (Followers: 9)
Advanced Energy Materials     Hybrid Journal   (Followers: 17)
Applied Mechanics Reviews     Full-text available via subscription   (Followers: 24)
BER : Consumer Goods Industries Survey     Full-text available via subscription  
BER : Intermediate Goods Industries Survey     Full-text available via subscription   (Followers: 1)
BER : Manufacturing Survey : Full Survey     Full-text available via subscription   (Followers: 2)
CORROSION     Full-text available via subscription   (Followers: 3)
Electric Power Components and Systems     Hybrid Journal   (Followers: 7)
Engenharia AgrĂ­cola     Open Access  
Foundations and Trends® in Electronic Design Automation     Full-text available via subscription  
High Speed Machining     Open Access   (Followers: 1)
High Temperature Materials and Processes     Hybrid Journal   (Followers: 5)
International Journal of Machine Tools and Manufacture     Hybrid Journal   (Followers: 5)
International Journal of Machining and Machinability of Materials     Hybrid Journal   (Followers: 6)
International Journal of Manufacturing Technology and Management     Hybrid Journal   (Followers: 7)
International Journal of Precision Technology     Hybrid Journal  
International Journal of Rapid Manufacturing     Hybrid Journal   (Followers: 2)
International Journal of Rotating Machinery     Open Access   (Followers: 2)
Journal of Machinery Manufacture and Reliability     Hybrid Journal   (Followers: 1)
Journal of Machinery Manufacturing and Automation     Open Access   (Followers: 2)
Journal of Mechanics     Hybrid Journal   (Followers: 16)
Journal of Strain Analysis for Engineering Design     Hybrid Journal   (Followers: 5)
Journal of Terramechanics     Hybrid Journal   (Followers: 1)
Machine Design     Partially Free   (Followers: 13)
Machines     Open Access   (Followers: 1)
Materials     Open Access   (Followers: 5)
Mechanics Based Design of Structures and Machines: An International Journal     Hybrid Journal   (Followers: 3)
Micromachines     Open Access   (Followers: 2)
Practical Machinery Management for Process Plants     Full-text available via subscription  
Pump Industry Analyst     Full-text available via subscription  
Russian Engineering Research     Hybrid Journal  
Sensor Review     Hybrid Journal   (Followers: 1)
Surface Engineering and Applied Electrochemistry     Hybrid Journal   (Followers: 5)
Journal Cover   International Journal of Machine Tools and Manufacture
  [SJR: 3.363]   [H-I: 81]   [5 followers]  Follow
    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 0890-6955
   Published by Elsevier Homepage  [2812 journals]
  • Integrated post-processor for 5-axis machine tools with geometric errors
           compensation
    • Abstract: Publication date: July 2015
      Source:International Journal of Machine Tools and Manufacture, Volume 94
      Author(s): Nuodi Huang , Yongqiao Jin , Qingzhen Bi , Yuhan Wang
      Geometric errors of 5-axis machine tools introduce great deviation in real workpiece manufacture and on-machine measurement like touch-trigger probe measurement. Compensation of those errors by toolpath modification is an effective and distinguished method considering the machine calibration costs and productivity. Development of kinematic transformation model is involved in this paper to clarify the negative influences caused by those errors at first. The deviation of the designed toolpath and the real implemented toolpath in workpiece coordinate system is calculated by this model. An iterative compensation algorithm is then developed through NC code modification. The differential relationship between the NC code and the corresponding real toolpath can be expressed by Jacobi matrix. The optimal linear approximation of the compensated NC code is calculated by utilizing the Newton method. Iteratively applying this approximation progress until the deviation between the nominal and real toolpath satisfies the given tolerance. The variations of the geometric errors at different positions are also taken into account. To this end, the nominal toolpath and the geometric errors of the specific 5-axis machine tool are considered as the input. The new compensated NC code is generated as the output. The methodology can be directly utilized as the post-processor. Experimental results demonstrate the sensibility and effectiveness of the compensation method established in this study.


      PubDate: 2015-05-16T02:09:09Z
       
  • CFRP drilling: Fundamental study of local feed force and consequences on
           hole exit damage.
    • Abstract: Publication date: July 2015
      Source:International Journal of Machine Tools and Manufacture, Volume 94
      Author(s): Cédric Bonnet , Gérard Poulachon , Joël Rech , Yannick Girard , Jean Philippe Costes
      Carbon Fiber-Reinforced by Plastic (CFRP) is now commonly used in the aircraft industry. The main challenge is to manufacture this difficult-to-cut work material, considering its quality criteria and economical aspects. Drilling is the main machining operation required for the assembly of the aircraft structure. In this paper, results are presented and discussed regarding exit delamination studied at a local scale. Because of the anisotropic properties of CFRP, the fiber cutting modes change with the composite sequence combined with the drill revolution parameters. The local feed forces generated by the cutting edge on the hole bottom may be correlated with delaminating aspects. A posttreatment method is proposed to analyze precisely these feed force and cutting torque distributions. Appropriate ply sequences are identified in order to limit the mechanical load concentration and the risk of delamination or uncut fibers


      PubDate: 2015-05-16T02:09:09Z
       
  • Numerical modeling and experimental measurement of MQL impingement over an
           insert in a milling tool with inner channels
    • Abstract: Publication date: July 2015
      Source:International Journal of Machine Tools and Manufacture, Volume 94
      Author(s): Arnaud Duchosal , Sana Werda , Roger Serra , René Leroy , Hédi Hamdi
      This paper compares experimental and numerical simulations of liquid film formation for different rotating velocities of a milling tool. The numerical model used was based on an unsteady Reynolds–Average Navier–Stokes (RANS) formulation and multiphase Lagrangian model for liquid film formation by the droplet impingement model on a solid surface. The details of spray–wall interaction are presented and the model was used to simulate the liquid film formation in the Micro-Quantity Lubrication (MQL) coolant process for different milling tool velocities. The shape and the size of the liquid film obtained by the calculation and the experiments were compared to improve understanding of the MQL cooling process. Overall, good agreement was observed between the numerical and the experimental measurements of liquid film size from an estimated numerical film thickness border. This study provided greater understanding of oil mist behavior. The impingement analyses predicted better lubrication when highly oriented channels and high inlet pressure were used, especially in High Speed Machining.
      Graphical abstract image

      PubDate: 2015-05-16T02:09:09Z
       
  • Investigation of the effects of spindle unbalance induced error motion on
           machining accuracy in ultra-precision diamond turning
    • Abstract: Publication date: July 2015
      Source:International Journal of Machine Tools and Manufacture, Volume 94
      Author(s): P. Huang , W.B. Lee , C.Y. Chan
      In ultra-precision machining, error motions of the aerostatic bearing spindle (ABS) have significant effects on the machining accuracy. Spindle unbalance is a critical factor attributing to error motions of the ABS. Much work currently has been focused on the measurement of error motions and spindle balancing. However, the unbalance induced spindle error motion (UISEM) and the corresponding effects on machining accuracy are not well understood. In this paper, a dynamics model of the ABS was established to characterize the UISEM and its dynamic behavior with consideration of the unbalance effects. A series of groove turning experiments were especially designed to investigate the UISEM. Good agreement between theoretical and experimental results was achieved, demonstrating the low frequency enveloping phenomenon of the error motions of the ABS, identified as the unique superposition effects of two motion components at high frequency in the spindle vibration. In addition, the experimental result reveals that the relative distance between the rotational axis of the ABS and the tool tip varies with respect to the different spindle speeds, significantly degrading the machining accuracy.


      PubDate: 2015-05-16T02:09:09Z
       
  • Study on mechanics and key technologies of laser nondestructive
           mirror-separation for KDP crystal
    • Abstract: Publication date: July 2015
      Source:International Journal of Machine Tools and Manufacture, Volume 94
      Author(s): Leimin Deng , Huan Yang , Xiaoyan Zeng , Baoye Wu , Peng Liu , Xizhao Wang , Jun Duan
      KDP crystal is an important electro-optic material in various laser systems. At present, the greatest difficulty is the cutting and polishing of large-scale crystals. In this study, a laser nondestructive mirror-separation technology (LNMS) for KDP crystal has been developed for the first time by skillfully adopting femtosecond laser pretreating and fiber laser separating. The separating efficiency of LNMS is at least 200 times faster than that of traditional mechanical cutting, and a nondestructive mirror-separated crystal sidewall with surface roughness (S a ) of 4.7nm (P−V) and 2.1nm (RMS), flatness of 5.433μm and an angular precision about 0.06° could be obtained using the LNMS method. The effects of laser separating parameters, including laser power, laser moving speed and internal stress release on separating accuracy and quality, were investigated and optimized; meanwhile its principle was expounded as well as its mechanism was discussed. The experimental and analyzed results show that the LNMS technology may also have a prospect in the analysis of residual stress distribution inside KDP crystal. A numerical simulation on the thermal stress in the LNMS separating process of KDP crystal was developed to analyze the separating mechanism, which is in good agreement with the theoretical analysis and experimental results.
      Graphical abstract image

      PubDate: 2015-05-16T02:09:09Z
       
  • Feasibility study of in-process compensation of deformations in flexible
           milling
    • Abstract: Publication date: July 2015
      Source:International Journal of Machine Tools and Manufacture, Volume 94
      Author(s): Eduardo Diez , Hilde Perez , Juan Marquez , Antonio Vizan
      During the machining of thin-walled parts, deformation can occur resulting in dimensional errors. These dimensional errors cause a variation on cutting forces. From the actual measured cutting forces and the estimated forces resultant from rigid machining, it is possible to determine the value of this deformation. Based on this, an on-line system for compensating workpiece errors, has been developed. The system is based on correcting the relative position of the tool-workpiece during machining by means of a piezoelectric actuator. The objective is achieved in real time to compensate for the part deformations from the measurement of the cutting forces, without the programming of the tool path trajectories in the machine tool being affected.


      PubDate: 2015-05-16T02:09:09Z
       
  • Theoretical and experimental investigation on the novel
           end-fly-cutting-servo diamond machining of hierarchical
           micro-nanostructures
    • Abstract: Publication date: July 2015
      Source:International Journal of Machine Tools and Manufacture, Volume 94
      Author(s): Zhiwei Zhu , Suet To , Shaojian Zhang
      By combining the concepts of fast/slow tool servo and fly cutting, a novel end-fly-cutting-servo (EFCS) system with four-axis motions is proposed for deterministic generation of hierarchical micro-nanostructures, which are conventionally difficult for both mechanical and non-mechanical methods to achieve. In the EFCS system, an intricately shaped primary surface is generated by material removal, while the desired secondary nanostructure is simultaneously constructed using residual tool marks by actively controlling the tool loci. The optimal toolpath determination strategy, as well as surface generation algorithm for the EFCS system, has been developed with consideration of geometries and installation poses of the diamond tool. Numerical simulation of surface generation is conducted to demonstrate the effectiveness of the novel machining method and features of the obtained hierarchical structures. A nanostructured micro-aspheric array and a nanostructured F-theta freeform surface are successfully fabricated in experiments. This research provides a very promising technique for the generation of hierarchical micro-nanostructures to realize performance integration of artificial components.
      Graphical abstract image

      PubDate: 2015-05-16T02:09:09Z
       
  • Analysis of the transient backlash error in CNC machine tools with closed
           loops
    • Abstract: Publication date: June 2015
      Source:International Journal of Machine Tools and Manufacture, Volume 93
      Author(s): Shengyu Shi , Jing Lin , Xiufeng Wang , Xiaoqiang Xu
      Backlash is one of the most commonly encountered nonlinear phenomena in feed drives, which degrades the contouring accuracy of machine tools. The full-closed loop could suppress the adverse effects of backlash significantly. However, a transient backlash error (TBE) remains. Unfortunately, the mechanism of the TBE is completely different from that of the conventional backlash error. The purpose of this paper is to reveal the mechanism of the TBE. First, for the demonstration of the TBE, a general model is derived from an industrial feed drive with the closed loop control. Subsequently, the model is simplified further. Based on the simplified model, the mechanism is described and clarified in detail, and furthermore, the analytical formulations of TBEs are derived for the cases of straight line and circle, respectively. Finally, several simulations and experiments are given to validate the proposed models and formulations.


      PubDate: 2015-05-16T02:09:09Z
       
  • Investigation of material deformation mechanism in double side incremental
           sheet forming
    • Abstract: Publication date: June 2015
      Source:International Journal of Machine Tools and Manufacture, Volume 93
      Author(s): B. Lu , Y. Fang , D.K. Xu , J. Chen , S. Ai , H. Long , H. Ou , J. Cao
      Double side incremental forming (DSIF) is an emerging technology in incremental sheet forming (ISF) in recent years. By employing two forming tools at each side of the sheet, the DSIF process can provide additional process flexibility, comparing to the conventional single point incremental forming (SPIF) process, therefore to produce complex geometries without the need of using a backing plate or supporting die. Although this process has been proposed for years, there is only limited research on this process and there are still many unanswered open questions about this process. Using a newly developed ISF machine, the DSIF process is investigated in this work. Focusing on the fundamental aspects of material deformation and fracture mechanism, this paper aims to improve the understanding of the DSIF process. Two key process parameters considered in this study include the supporting force and relative position between master and slave tools. The material deformation, the final thickness distribution as well as the formability under varying conditions of these two process variables are investigated. To obtain a better understanding from the experimental results, an analytical model has been developed to evaluate the stress state in the deformation zone. Using the developed model, an explicit relationship between the stress state and key process parameters can be established and a drop of stress triaxiality can be observed in the double contact zone, which explains the enhanced formability in the DSIF process. Based on the analytical and experimental investigation, the advancements and challenges of the DSIF process are discussed with a few conclusions drawn for future research.


      PubDate: 2015-05-16T02:09:09Z
       
  • Thermally induced positioning error modelling and compensation based on
           thermal characteristic analysis
    • Abstract: Publication date: June 2015
      Source:International Journal of Machine Tools and Manufacture, Volume 93
      Author(s): Wenlong Feng , Zihan Li , Qunying Gu , Jianguo Yang
      To decrease the thermally induced positioning error of machine tools, a novel approach for modelling and compensation is proposed in this study. The cause of this error is determined to be dynamic pitch error, and its manifestations are discussed in this study. The thermal expansion of a screw shaft under the influence of friction heat is analysed theoretically, and a mathematical model of the transient temperature of the screw with regard to time is developed. A temperature calculation method in the cases of cooling in the process of warming up and warming up after cooling is also introduced. To solve the problem of heat unevenly distributed of the entire screw shaft, the screw shaft is divided into several evenly distributed heat regions, and the established model is fit for each region. The synthetic model is established by superposition of all models of the regions. In addition, an external error compensation system is developed based on a function called external mechanical origin offset in Fanuc CNC systems. Six test pieces are machined to validate the accuracy of the model and the effectiveness of the error compensation system. The result indicates that the accuracy of the pieces is significantly improved compared with that obtained without error compensation. The synthetic model of the entire screw shaft is demonstrated to be an effective approach to improve the accuracy of machine tools.


      PubDate: 2015-05-16T02:09:09Z
       
  • Precise contour following for biaxial systems via an A-type iterative
           learning cross-coupled control algorithm
    • Abstract: Publication date: June 2015
      Source:International Journal of Machine Tools and Manufacture, Volume 93
      Author(s): Jianhua Wu , Chao Liu , Zhenhua Xiong , Han Ding
      This paper proposes an A-type iterative learning cross-coupled control (CCC) algorithm for biaxial systems. An algebraic equation based contour error model is used as the CCC input. This model has the advantage that it is zero if and only if the real value vanishes. The iterative learning CCC is designed to make its input converge to zero. Hence, it is expected to that the contour error will converge to zero as well. After analyzing the control algorithm convergence condition in the frequency domain, the proposed method is implemented on a motion stage. Experimental results show that the algorithm perfectly follows contours as the cycles approach infinity regardless of whether tracking errors are small or large.


      PubDate: 2015-05-16T02:09:09Z
       
  • High-speed dry electrical discharge machining
    • Abstract: Publication date: June 2015
      Source:International Journal of Machine Tools and Manufacture, Volume 93
      Author(s): Yang Shen , Yonghong Liu , Yanzhen Zhang , Hang Dong , Wanyun Sun , Xiaolong Wang , Chao Zheng , Renjie Ji
      A novel high-speed dry electrical discharge machining (EDM) method was proposed in this study. Using this method, the material can be rapidly melted by extremely high discharge energy and flushed out of the discharge gap by high-pressure and high-speed air flow. The material removal rate (MRR) of dry EDM was significantly improved by the proposed method. The MRR of dry EDM is usually in tens mm3/min, whereas the MRR of the proposed method can be as high as 5162mm3/min, which improves the MRR by 2nd to 3rd order of magnitude. Investigation was conducted systemically. The influences of work piece polarity, discharge current, pulse duration time, gas pressure, and electrode rotation speed on machining performance were studied. The machining mechanism of this method was thoroughly analyzed. Moreover, the re-solidified layer, surface morphology, elementary composition, and phase of AISI 304 stainless steel for high-speed dry EDM were also investigated. Theoretical and technical foundations were laid for the industry application of dry EDM.


      PubDate: 2015-05-16T02:09:09Z
       
  • IFC - Editorial board
    • Abstract: Publication date: June 2015
      Source:International Journal of Machine Tools and Manufacture, Volume 93




      PubDate: 2015-05-16T02:09:09Z
       
  • Evaluation of measurement uncertainty in H-drive stage during high
           acceleration based on Monte Carlo method
    • Abstract: Publication date: June 2015
      Source:International Journal of Machine Tools and Manufacture, Volume 93
      Author(s): Yongmeng Liu , Maoqiang Yuan , Jieru Cao , Jiwen Cui , Jiubin Tan
      This paper presents an integrated error propagation analysis method to estimate the measurement uncertainty using Monte Carlo method in order to analyze the measurement accuracy of an H-drive stage with air bearing during high acceleration subjected to the influence of a variety of errors, including straightness errors, thermal errors, deformation errors and air bearing gap change errors caused by acceleration force. Firstly, the integrated error propagation model of an H-drive stage is built combined with the effects of the various error sources based on the multi-body system and instrument precision theory. Then these errors are identified by experiments and finite element analysis and the influence of each error in six degrees of freedom displacement is obtained. Finally, the displacement measurement uncertainty of the stage in the reference coordinate system is evaluated by Monte Carlo method, within 95% probability, the displacement measurement results and the expanded uncertainty in x and y directions are calculated x=(165.000±0.064)mm and y=(195.000±0.054)mm respectively. The proposed method can be used in the error budget of precise machine design and applied in error compensation to improve the measurement and control accuracy of precise machine workpiece stage.


      PubDate: 2015-05-16T02:09:09Z
       
  • Augmented Taylor's expansion method for B-spline curve interpolation for
           CNC machine tools
    • Abstract: Publication date: July 2015
      Source:International Journal of Machine Tools and Manufacture, Volume 94
      Author(s): Mo Chen , Wan-Sheng Zhao , Xue-Cheng Xi
      In computer numerical control (CNC) systems, parametric curves can be used instead of a large amount of linear blocks to describe tool paths for freeform surface or curve machining. However, existing parametric curve interpolation methods may cause large feed fluctuations or even a failure of the machining process near the sharp corners of a parametric curve. Therefore, a parametric curve interpolation method with an error correction and failure prevention scheme is required. In this paper, the augmented Taylor's expansion (ATE) method for computing B-spline curve parameters is proposed. A group of calibrators consisting of the knots and the arc lengths between adjacent knots are pre-computed before the interpolation starts. The parameter is computed based on Heun's method in a prediction–correction manner, and the accumulated errors caused by the cut-off errors of Taylor's expansion are eliminated by the calibrators at the knots. To cope with the extreme cases that usually occur near the sharp corners of a curve, a linear parametric interpolation between the previous parameter and its next calibrator is carried out when Heun's method fails to obtain a parameter in the domain. Simulation and experimental results show that, when the arc length increments are kept small enough near the sharp corners, the ATE method attains high accuracy and robust computation. The proposed method is also applicable to the NURBS curves.


      PubDate: 2015-05-16T02:09:09Z
       
  • Dynamic electromechanical coupling resulting from the air-gap fluctuation
           of the linear motor in machine tools
    • Abstract: Publication date: July 2015
      Source:International Journal of Machine Tools and Manufacture, Volume 94
      Author(s): Xiaojun Yang , Dun Lu , Jun Zhang , Wanhua Zhao
      This paper investigates a dynamic electromechanical coupling resulting from the air-gap fluctuation of the linear motor in machine tools. The modes of the mechanical vibration are analyzed firstly in the linear motor feed system. Then the influence of mechanical vibration on the air-gap fluctuation is researched. Based on the Maxwell's equation and energy method, the analytical expression of the motor thrust is established considering the air-gap fluctuation. Then we discuss the effects of air-gap fluctuation on the motor thrust. At last, the dynamic electromechanical coupling caused by the air-gap fluctuation is theoretically analyzed and verified by experiments. The results show that the mechanical vibration can affect the characteristics of the motor thrust conversely causing the fluctuation of the motor air-gap. The air-gap fluctuation can produce new thrust harmonics. These new thrust harmonics excite mechanical system again, and then the electromechanical coupling loop is formed, leading to a worse dynamic precision of the feed system. In addition, the couplings will aggravate with the increase of velocity and load.


      PubDate: 2015-05-16T02:09:09Z
       
  • Shear-thickening polishing method
    • Abstract: Publication date: July 2015
      Source:International Journal of Machine Tools and Manufacture, Volume 94
      Author(s): Min Li , Binghai Lyu , Julong Yuan , Chenchen Dong , Weitao Dai
      A shear-thickening polishing (STP) method utilizing the shear thickening mechanism of non-Newtonian power-law fluid based slurry is proposed for curved surface polishing. The STP principle and micro-material removal action are analyzed. The high-performance STP slurry with the shear-thickening rheological behaviors has been prepared. To achieve the material removal mechanism of STP process, based on the Preston formula, fluid dynamics and shear thickening mechanism, the material removal rate (MRR) model is established and the difference of MRR between theoretical and experimental results is 6.12%. The experimental and theoretical tests of STP process are conducted to investigate the influences of polishing velocity, abrasive concentration and grain size on MRR and surface roughness. Compared with Newtonian fluid slurry, STP slurry can achieve much higher MRR and better surface quality due to shear-thickening effect. MRR of Cr12Mo1V1 (die steel) is up to 13.69μm/h, and surface roughness is reduced from R a 105.95nm to R a 5.1nm within 0.5h of processing. This indicates that STP is a promising processing method for precision finishing or polishing.


      PubDate: 2015-05-16T02:09:09Z
       
  • Prediction and identification of rotary axes error of non-orthogonal
           five-axis machine tool
    • Abstract: Publication date: July 2015
      Source:International Journal of Machine Tools and Manufacture, Volume 94
      Author(s): Dongju Chen , Lihua Dong , Yanhua Bian , Jinwei Fan
      This paper proposes an efficient and automated scheme to predict and identify the position and motion errors of rotary axes on a non-orthogonal five-axis machining centre using the double ball bar (DBB) system. Based on the Denavit-Hartenberg theory, a motion deviations model for the tilting rotary axis B and rotary C of a non-orthogonal five-axis NC machine tool is established, which considers tilting rotary axis B and rotary C static deviations and dynamic deviations that total 24. After analysing the mathematical expression of the motion deviations model, the QC20 double ball bar (DBB) from the Renishaw Company is used to measure and identify the motion errors of rotary axes B and C, and a measurement scheme is designed. With the measured results, the 24 geometric deviations of rotary axes B and C can be identified intuitively and efficiently. This method provides a reference for the error identification of the non-orthogonal five-axis NC machine tool.


      PubDate: 2015-05-16T02:09:09Z
       
  • On-machine measurement of location errors on five-axis machine tools by
           machining tests and a laser displacement senso
    • Abstract: Publication date: Available online 13 May 2015
      Source:International Journal of Machine Tools and Manufacture
      Author(s): Zhouxiang Jiang , Bao Song , Xiangdong Zhou , Xiaoqi Tang , Shiqi Zheng
      This paper proposes an on-machine measurement (OMM) of all location errors on five-axis machine tools. Five machining patterns are successively performed on a cubic workpiece. The basic idea is to use a set of large rotations of rotary axes to prolong the moving distance of linear axes when squareness errors of linear axes are identified. Then, a set of small rotations of rotary axes are used to decouple the squareness errors of linear and rotary axes. Based on this, the long and deep slots in previous machining tests are improved to be a set of short and shallow ones. These miniaturized slots reduce the material removal and minimize the influence of cutting force and thermal deformation on the measuring results. Then the cutting tool is substituted by a laser displacement sensor (LDS) to measure the mismatch between the finished surfaces of the corresponding slots. All the measured surfaces are located on the bottom of the slots to fit the LDS characteristic of one dimensional measurement. Three gestures of the rotary table and tilting head are used to implement the single-setup OMM and the influence of location errors on the measuring results is compensated. Validation of the identified values is also provided by a set of simple tests using different measuring instruments. The efficiency and accuracy of location errors measurement method on five-axis machine tools are improved.


      PubDate: 2015-05-16T02:09:09Z
       
  • Stiffness Analysis and Experiment of a Novel 5-DoF Parallel Kinematic
           Machine Considering Gravitational Effects
    • Abstract: Publication date: Available online 13 May 2015
      Source:International Journal of Machine Tools and Manufacture
      Author(s): Binbin Lian , Tao Sun , Yimin Song , Yan Jin , Mark Price
      In order to carry out high-precision machining of aerospace structural components with large size, thin wall and complex surface, this paper proposes a novel parallel kinematic machine (PKM) and formulates its semi-analytical theoretical stiffness model considering gravitational effects that is verified by stiffness experiments. From the viewpoint of topology structure, the novel PKM consists of two substructures in terms of the redundant and overconstrained parallel mechanisms that are connected by two interlinked revolute joints. The theoretical stiffness model of the novel PKM is established based upon the virtual work principle and deformation superposition principle after mapping the stiffness models of substructures from joint space to operated space by Jacobian matrices and considering the deformation contributions of interlinked revolute joints to two substructures. Meanwhile, the component gravities are treated as external payloads exerting on the end reference point of the novel PKM resorting to static equivalence principle. This approach is proved by comparing the theoretical stiffness values with experimental stiffness values in the same configurations, which also indicates equivalent gravity can be employed to describe the actual distributed gravities in an acceptable accuracy manner. Finally, on the basis of the verified theoretical stiffness model, the stiffness distributions of the novel PKM are illustrated and the contributions of component gravities to the stiffness of the novel PKM are discussed.


      PubDate: 2015-05-16T02:09:09Z
       
  • Laser polishing of selective laser melted Components
    • Abstract: Publication date: Available online 12 May 2015
      Source:International Journal of Machine Tools and Manufacture
      Author(s): S. Marimuthu , A. Triantaphyllou , M. Antar , D. Wimpenny , H. Morton
      The shape complexities of aerospace components are continuously increasing, which encourages industries to refine their manufacturing processes. Among such processes, the selective laser melting (SLM) process is becoming an economical and energy efficient alternative to conventional manufacturing processes. However, dependent on the component shape, the high surface roughness observed with SLM parts can affect the surface integrity and geometric tolerances of the manufactured components. To account for this, laser polishing of SLM components is emerging as a viable process to achieve high-quality surfaces. This report details an investigation carried out to understand the basic fundamentals of continuous wave laser polishing of SLM samples. A numerical model, based on a computational fluid dynamic formulation, was used to assist the understanding of melt pool dynamics, which significantly controls the final surface roughness. The investigation identified the input thermal energy as the key parameter that significantly affect the melt pool convection, and essentially controls the surface quality. Minimum meltpool velocity is essential to achieve wider laser polished track width with good surface finish. Experimental results showed a reduction of surface roughness from 10.2μm to 2.4μm after laser polishing with optimised parameters. Strategies to control the surface topology during laser polishing of SLM components are discussed.


      PubDate: 2015-05-16T02:09:09Z
       
  • Optimal Process Parameters for Parallel Turning Operations on Shared
           Cutting Surfaces
    • Abstract: Publication date: Available online 12 May 2015
      Source:International Journal of Machine Tools and Manufacture
      Author(s): C. Brecher , A. Epple , S. Neus , M. Fey
      To enhance productivity in industrial settings, turning machines are increasingly being used with multiple turrets. This machine configuration enables parallel machining at different or at the same cutting surface using independent tools. However, there is a dynamic interaction between the cutting processes due to the waviness induced on the shared cutting surface as well as due to the dynamic coupling through the machine structure. This dynamic interaction can lead to a significant reduction of the chip removal rate compared to two conventional processes. To utilize the productivity advantage of parallel turning processes, an examination of the process-machine-interaction considering the dynamic coupling of the cutting processes is required. Hence, this paper discusses parametrization for stable processing of parallel turning operations. Therefore, time and frequency domain-based simulation models are developed and matched with experimental cutting tests. Additionally, the influence of the radial angle between the tools is investigated. This angle influences the dead time between two successive cuts for parallel turning processes on the same cutting surface. The dead time in turn directly affects the process stability limit. Thus, with the help of the developed simulation models, an optimal process parametrization for parallel turning operations can be determined.


      PubDate: 2015-05-16T02:09:09Z
       
  • Stochastic modelling of abrasive waterjet footprints using finite element
           analysis
    • Abstract: Publication date: Available online 12 May 2015
      Source:International Journal of Machine Tools and Manufacture
      Author(s): P. Lozano Torrubia , D.A. Axinte , J. Billingham
      The proposal of erosion models to predict the jet footprint during abrasive waterjet machining is a key element for the development of this technology, but it is very challenging because of the inherent fluctuations of the process. This issue becomes critical when the size of the cutting systems is reduced, since the relative size of these deviations increases. The present paper considers for the first time a modelling framework capable of predicting the average shape of AWJM footprints and, of great novelty, the variability along the trench, combining finite element analysis and Monte Carlo methods, and verifying the model using different feed speeds and tilt angles. For that purpose, the relevance of each random parameter, such as shape (sharpness), size and relative orientation of the abrasive particles, has been investigated through parametric studies on these variables. Multiple particle simulations with randomly generated input were performed to determine the effect of operating parameters in the overall variability of the jet footprint. The process was simulated using Abaqus 6.14 as multiple garnet particles hitting a target of Ti-6Al-4V at very high velocity, eroding the target by plastic deformation and material removal. The model shows successfully the influence of single particle parameters, such as the shape, on the surface variability. The results for the footprint variability show that stochastic methods are suitable to model these fluctuations, and it is also shown that this approach yields accurate estimates of the average profile after multiple jet passes with error less than 5%.


      PubDate: 2015-05-16T02:09:09Z
       
  • A Position Independent Geometric Errors Identification and Correction
           Method for Five–Axis Serial Machines based on Screw Theory
    • Abstract: Publication date: Available online 4 May 2015
      Source:International Journal of Machine Tools and Manufacture
      Author(s): Jixiang Yang , J.R.R. Mayer , Yusuf Altintas
      Position independent geometric errors (PIGEs), which are caused by imperfect assembly of five-axis machine tools, need to be identified and compensated to improve the accuracy of machined parts. This paper presents the identification and correction of serial five-axis machine tools based on screw theory. The proposed identification model is based on a generalized Jacobian function for a variety of five-axis machine configurations as opposed to the models based on homogeneous transformation matrices (HTMs). The screw theory allows a global description of rigid body motion without constructing the local frames on each drive module as required by the HTMs method. An explicit inverse kinematics model is proposed to compensate the geometric errors directly as opposed to the existing approximate linearized or iterative methods. The proposed identification and correction of PIGEs methods are verified through simulations and experiments with ball-bar tests on a five-axis machine tool.


      PubDate: 2015-05-16T02:09:09Z
       
  • IFC - Editorial board
    • Abstract: Publication date: May 2015
      Source:International Journal of Machine Tools and Manufacture, Volume 92




      PubDate: 2015-05-16T02:09:09Z
       
  • Hyper-third order full-discretization methods in milling stability
           prediction
    • Abstract: Publication date: May 2015
      Source:International Journal of Machine Tools and Manufacture, Volume 92
      Author(s): C.G. Ozoegwu , S.N. Omenyi , S.M. Ofochebe
      Full-discretization methods beyond the third order is not yet explored except for this work in which the fourth and fifth order methods are presented. It is seen in earlier works that accuracy of milling stability analysis using the full-discretization method rises from the first order method to the second order method and continues to rise to the third order method. It is seen in this work that the rise in accuracy of the full-discretization method with order continues to the proposed fourth order method where it (accuracy) peaks before a decline to the proposed fifth order method.


      PubDate: 2015-05-16T02:09:09Z
       
  • Tube electrode high-speed electrochemical discharge drilling using
           low-conductivity salt solution
    • Abstract: Publication date: May 2015
      Source:International Journal of Machine Tools and Manufacture, Volume 92
      Author(s): Yan Zhang , Zhengyang Xu , Di Zhu , Jun Xing
      Film cooling holes are widely used in the aerospace industry, and their fabrication requires high machining speed and accuracy, as well as good surface quality. Tube electrode high-speed electrochemical discharge drilling (TSECDD) is a promising hybrid machining method for the fabrication of film cooling holes in difficult-to-machine superalloys. An electrochemical reaction can occur if a low-conductivity salt solution is used in the drilling. Materials can also be removed at a high speed using electrical discharge machining (EDM). Thus, TSECDD and electrochemical machining (ECM) can be combined into a unique machining process using a low-conductivity salt solution. This machining process achieves both a high machining speed and good surface finish. In this study, the material removal mechanism of TSECDD was studied using a low-conductivity salt solution, and comparisons with high-speed electrical discharge drilling were made. The performance of the process was investigated using salt solutions of various conductivities. The results show that there are different material removal mechanisms in the frontal gap and the lateral gap and that, in the latter, there is a transition from EDM to ECM. Experiments conducted using TSECDD confirm that the use of this process with a low-conductivity salt solution can improve the machining surface and machining efficiency achieved. The results also show that the use of a low-conductivity solution improves the material removal rate, the hole diameter, and the taper angle.


      PubDate: 2015-05-16T02:09:09Z
       
  • Optimal spindle speed determination for vibration reduction during
           ball-end milling of flexible details
    • Abstract: Publication date: May 2015
      Source:International Journal of Machine Tools and Manufacture, Volume 92
      Author(s): Krzysztof J. Kalinski , Marek A. Galewski
      In the paper a method of optimal spindle speed determination for vibration reduction during ball-end milling of flexible details is proposed. In order to reduce vibration level, an original procedure of the spindle speed optimisation, based on the Liao–Young criterion [1], is suggested. As the result, an optimal, constant spindle speed value is determined. For this purpose, non-stationary computational model of machining process is defined. As a result of modelling, a hybrid system is described. This model consists of following subsystems, i.e. stationary model of one-side-supported flexible workpiece (modal subsystem), non-stationary discrete model of ball-end mill (structural subsystem) and conventional contact point between tool and workpiece (connective subsystem). The method requires identification of some natural frequencies of stationary modal subsystem. To determine them, appropriate modal experiments have to be performed on the machine tool, just before machining. Examples of vibration surveillance during cutting process on two high speed milling machines Mikron VCP 600 and Alcera Gambin 120CR are illustrated.


      PubDate: 2015-05-16T02:09:09Z
       
  • Prediction of frequency response function (FRF) of asymmetric tools from
           the analytical coupling of spindle and beam models of holder and tool
    • Abstract: Publication date: May 2015
      Source:International Journal of Machine Tools and Manufacture, Volume 92
      Author(s): O. Özşahin , Y. Altintas
      The prediction of chatter stability diagrams in milling requires accurate frequency response functions (FRF) at the tool – workpiece contact zone. Traditionally, the most accurate FRFs are best obtained through the experimental modal testing of each tool, which is costly. This paper presents analytical modeling and coupling procedures for spindle–holder–tool assemblies with asymmetric tools. Tools and holders are analytically modeled with continuous Timoshenko beams, while considering variation of the cross section geometry of the fluted sections and helix angle. While each solid part segments with varying geometry are assembled with rigid receptance coupling, the holder–spindle and tool–holder are coupled using contact stiffness and damping. The asymmetric cross sections of the helical end mills cause the variation of FRF as a function of the spindle's angular position. It is experimentally proven that the proposed method can predict the FRFs as the asymmetric tools rotate.


      PubDate: 2015-05-16T02:09:09Z
       
  • A new geometric error modeling approach for multi-axis system based on
           stream of variation theory
    • Abstract: Publication date: May 2015
      Source:International Journal of Machine Tools and Manufacture, Volume 92
      Author(s): Hao Tang , Ji-an Duan , Shuhuai Lan , Huanyi Shui
      This paper introduces a new geometric error modeling approach for multi axes system (MAS) based on stream of variation (SOV) theory, especially for multi-axis precision stage. SOV is used for measuring product quality for some complicated multi operations system, which is widely used in error propagation in engineering field. This paper introduces SOV concept into geometric error modeling for MAS. Instead of different process in manufacture, the new error modeling approach regards each axis as a station in MAS, and calculates the deviations after each station which is considered as upstream factor to next station. It is clear to observe how geometric errors give influence and how deviations accumulate. Different with conventional methods which are only used for error compensation in machine tools, the new error model is beneficial for sensitive error control and optimal configuration selection in design part. In addition, the new error modeling has some merits such as debugging easily due to observe the deviations after every station. A case study of new error modeling procedure for six-axis stage (SAS) in optoelectronic packaging system (OPS) is developed, and applications related to error reduction order and optimal configuration selection are processed based on the new error model.


      PubDate: 2015-05-16T02:09:09Z
       
  • Chatter identification in end milling process based on EEMD and nonlinear
           dimensionless indicators
    • Abstract: Publication date: May 2015
      Source:International Journal of Machine Tools and Manufacture, Volume 92
      Author(s): Hongrui Cao , Kai Zhou , Xuefeng Chen
      Vibration analysis is widely used to reveal the fundamental cutting mechanics in machining condition monitoring. In this work, vibration signals generated in different chatter conditions as well as stable cutting are studied to understand chatter characteristics. Considering the nonlinear and non-stationary properties of chatter vibration in milling process, a self-adaptive analysis method named ensemble empirical mode decomposition (EEMD) is adopted to analyze vibration signals and two nonlinear indices are extracted as chatter indicators. Firstly, the vibration signal is preprocessed with a comb filter to eliminate the interference of rotation frequency, tooth passing frequency and their harmonics. Secondly, EEMD is applied to decompose the filtered signal into a set of intrinsic mode functions (IMFs). Sensitive IMFs containing rich chatter information are selected. With the development of chatter, an accumulation phenomenon appears in the spectrum of sensitive IMFs and chatter frequencies are modulated by the rotation frequency and tooth passing frequency. Finally, two nonlinear dimensionless indices within the range of [0, 1], i.e., C 0 complexity and power spectral entropy, are extracted from the sensitive IMFs in both time domain and frequency domain. The proposed method is verified with well-designed cutting tests. It is found that, the stochastic noise dominates in the sensitive IMFs of stable cutting and both the C 0 complexity value and power spectral entropy are the largest; with the increase of chatter severity level, the periodic chatter components dominate gradually and the proportion of stochastic noise decreases, and thus these two indicators decrease.


      PubDate: 2015-05-16T02:09:09Z
       
  • Kinematics and trajectory of both-sides cylindrical lapping process in
           planetary motion type
    • Abstract: Publication date: May 2015
      Source:International Journal of Machine Tools and Manufacture, Volume 92
      Author(s): Julong Yuan , Weifeng Yao , Ping Zhao , Binghai Lyu , Zhixiang Chen , Meipeng Zhong
      The both-sides lapping process in planetary motion type is proposed in this paper to lap and polish the cylindrical surface of bearing roller. The rolling speed of roller is the key kinematical parameter that affects the generation of cylindrical surface of roller. Through analysis of friction forces and pure rolling motion, it was discovered that the rolling speed of roller only depends on the rotation speed of lower plate rather than upper plate. Based on the above result, the geometry and kinematics of workpiece in this method is described, and the functions are proved valid by an experiment in which the rolling speed of roller is observed in video. By theoretical tests under different speed conditions, it is indicated that the roller's rolling speed varies with respect to time along a nonstandard cosine curve with an offset, its amplitude depends on the speeds of lower plate rotation and carrier circulation, and its offset depends on the speeds of lower plate rotation and carrier rotation. Based on geometry and kinematics, the trajectories on the cylindrical surface of roller and on the flat surface of plate are both described and simulated. The standard deviation and the range of path curve length distribution density are applied to numerically evaluate and analyze the trajectory distribution. The effect of speed parameters on the trajectory distribution, and the generation of trajectory with respect to time are investigated.


      PubDate: 2015-05-16T02:09:09Z
       
  • A method to predict position-dependent structural natural frequencies of
           machine tool
    • Abstract: Publication date: May 2015
      Source:International Journal of Machine Tools and Manufacture, Volume 92
      Author(s): Bo Luo , Dawei Pan , Hui Cai , Xinyong Mao , Fangyu Peng , Kuanmin Mao , Bin Li
      Machine tool structure has a strong influence on the dynamic properties of the tool. The change of a machine tool's structure will cause variations in the dynamic parameters of the entire tool, such as its natural frequency, which will result in changes to the stability of the tool and poor machining quality. Thus, a study on the variations of machine tool dynamics is essential for high performance cutting. In this paper, using the mass change method, a basic mathematical model for predicting the natural frequency change resulting from structural change was presented followed by an experimental validation of the model. The mathematical model indicates that structural change will lead to the outward variation of the natural frequency, which is essentially related to the change of the squared mode shape values between the original position and the modified position of the moving component. With this natural frequency change rate prediction model, the natural frequency in the case of structural change can be easily predicted. The predicted results indicate that the positional change of different moving components has differing influences on the natural frequency of the machine tool.


      PubDate: 2015-05-16T02:09:09Z
       
  • Three-dimensional characteristics analysis of the wire-tool vibration
           considering spatial temperature field and electromagnetic field in WEDM
    • Abstract: Publication date: May 2015
      Source:International Journal of Machine Tools and Manufacture, Volume 92
      Author(s): Zhi Chen , Yu Huang , Hao Huang , Zhen Zhang , Guojun Zhang
      In this paper, a three-dimensional multi-physics coupling model (thermal model, electromagnetic field model and structural model) is proposed for analyzing and controlling the vibration of wire electrode in cutting thin plate process. Firstly, a three-dimensional thermal model is developed to evaluate temperature distribution of wire electrode considering heat convection and heat conduction, and the numerical solutions of wire temperature increment are performed under different process parameters. Secondly, the mechanism of electromagnetic force acting on wire tool is clarified in detail, and a spacial finite element method (FEM) program is designed to analyze the electromagnetic field considering electromagnetic induction. Then, combining thermal model with electromagnetic field model, and conventional structural model, a multi-physics coupling model is established to acquire the frequency and amplitude of wire vibration under random multiple-spark discharges. Furthermore, the simulational results of multi-physics coupling model on wire vibration show a good agreement with experimental data, and the influencing rules of processing parameters on wire vibration are also illustrated to seek the best parameter combination. Eventually, three practical methods are presented to restrain wire vibration performance, and the significant effects on suppressing the wire vibration and improving geometric accuracy have been obtained.


      PubDate: 2015-05-16T02:09:09Z
       
  • Corrigendum to: “An efficient linear approximation of acceleration
           method for milling stability prediction” [Int. J. Mach. Tools Manuf.
           74 (2013) 56–64]
    • Abstract: Publication date: May 2015
      Source:International Journal of Machine Tools and Manufacture, Volume 92
      Author(s): Tao Huang , Xiaoming Zhang , Xiaojian Zhang , Han Ding



      PubDate: 2015-05-16T02:09:09Z
       
  • A review on spindle thermal error compensation in machine Tools
    • Abstract: Publication date: Available online 24 April 2015
      Source:International Journal of Machine Tools and Manufacture
      Author(s): Yang Li , Wanua Zhao , Shuhuai Lan , Jun Ni , Wenwu Wu , Bingheng Lu
      Thermal error caused by the thermal deformation is one of the most significant factors influencing the accuracy of the machine tool. Among all the heat sources which lead to the thermal distortions, the spindle is the main one. This paper presents an overview of the researches about the compensation of the spindle thermal error. Thermal error compensation is considered as a more convenient, effective and cost-efficient way to reduce the thermal error compared with other thermal error control and reduction methods. Based on the analytical calculation, numerical analysis and experimental tests of the spindle thermal error, the thermal error models are established and then applied for implementing the thermal error compensation. Different kinds of methods adopted in testing, modeling and compensating are listed and discussed. In addition, because the thermal key points are vital to the temperature testing, thermal error modeling, and even influence the effectiveness of compensation, various approaches of selecting thermal key points are introduced as well. This paper aims to give a basic introduction of the whole process of the spindle thermal error compensation and presents a summary of methods applied on different topics of it.


      PubDate: 2015-05-16T02:09:09Z
       
  • IFC - Editorial board
    • Abstract: Publication date: April 2015
      Source:International Journal of Machine Tools and Manufacture, Volume 91




      PubDate: 2015-05-16T02:09:09Z
       
  • The effect of the welding parameters and tool size on the thermal process
           and tool torque in reverse dual-rotation friction stir welding
    • Abstract: Publication date: April 2015
      Source:International Journal of Machine Tools and Manufacture, Volume 91
      Author(s): L. Shi , C.S. Wu , H.J. Liu
      Reverse dual-rotation friction stir welding (RDR-FSW) is a novel variant of conventional friction stir welding (FSW) process. The key feature is that the tool pin and the assisted shoulder are separated and rotate reversely and independently during welding process, thus it has great potential to improve the weld quality and lower the welding loads through adjusting the rotation speeds of the tool pin and the assisted shoulder independently. A 3D model of RDR-FSW process is developed to analyze the effect of welding parameters and tool size on the thermal process and the tool torque quantitatively. The model considers the effect of the welding parameters on the dimensionless slip rate and the friction coefficient between the tool-workpiece contact interfaces. It is found that with an increase of the radial distance, the locations of peak and valley values of heat generation rate at the shoulder-workpiece contact interfaces vary from the retreating side (RS) to the advancing side (AS) and from the AS to the RS, respectively. Although the reverse rotation of the tool pin and the assisted shoulder has little effect on the total heat generation, the corresponding material flow pattern and the distribution of heat generation rate lead to a more homogeneous temperature distribution and a much lower torque exerted on the workpiece in RDR-FSW process. The model is experimentally validated by comparing the measured thermal cycles with the calculated data.


      PubDate: 2015-05-16T02:09:09Z
       
  • Effect of grinding wheel spindle vibration on surface roughness and
           subsurface damage in brittle material grinding
    • Abstract: Publication date: April 2015
      Source:International Journal of Machine Tools and Manufacture, Volume 91
      Author(s): Jianbin Chen , Qihong Fang , Ping Li
      The external interference and vibration can seriously affect the machining errors in brittle materials grinding process. This paper proposes a new model to analyze the relationship between surface roughness (SR) and subsurface damage (SSD) depth on the basis of grinding kinematics analysis and indentation fracture mechanics of brittle materials taking the wheel spindle vibration into account. The basic equations, for example, equations of grain trajectory and penetration depth are derived in new forms. Based on the basic equations above, the existing SR and SSD formulae are modified for further study. The effects of grinding and vibration parameters on SR and SSD are respectively analyzed in detail. Results show that both SR and SSD increase with the increase of table speed and vibration amplitude resulting in bad surface and subsurface quality. On the other hand, both the increasing grinding speed and decreasing vibration frequency can improve the quality of ground surface and subsurface with small SR and SSD. In addition, the increase of initial grinding depth and vibration initial phase increase the depth of SSD but have little effect on SR. The penetration depth and distance between grain's tip and finished surface are the two main factors considered to cause the different effect laws on SR and SSD among these parameters. Experiment is carried out to validate the rationality of proposed model. The effect trends of various grinding parameters on SR obtained by our model consist with measured experimental data. The typical subsurface crack system is clearly revealed through the experimental observation on SSD using SEM. Finally, the relationship between the two is fitted utilizing quadratic polynomial. Results show that the SSD depth is nonlinear monotone increasing with SR and the fitting accuracy is more or less affected by both grinding and vibration parameters.


      PubDate: 2015-05-16T02:09:09Z
       
  • Analytical modeling of turn-milling process geometry, kinematics and
           mechanics
    • Abstract: Publication date: April 2015
      Source:International Journal of Machine Tools and Manufacture, Volume 91
      Author(s): Umut Karagüzel , Emre Uysal , Erhan Budak , Mustafa Bakkal
      This paper presents an analytical approach for modeling of turn-milling which is a promising cutting process combining two conventional machining operations; turning and milling. This relatively new technology could be an alternative to turning for improved productivity in many applications but especially in cases involving hard-to-machine material or large work diameter. Intermittent nature of the process reduces forces on the workpiece, cutting temperatures and thus tool wear, and helps breaking of chips. The objective of this study is to develop a process model for turn-milling operations. In this article, for the first time, uncut chip geometry and tool–work engagement limits are defined for orthogonal, tangential and co-axial turn-milling operations. A novel analytical turn-milling force model is also developed and verified by experiments. Furthermore, matters related to machined part quality in turn-milling such as cusp height, circularity and circumferential surface roughness are defined and analytical expressions are derived. Proposed models show a good agreement with the experimental data where the error in force calculations is less than 10% for different cutting parameters and less than 3% in machined part quality analysis.


      PubDate: 2015-05-16T02:09:09Z
       
  • A review of machine-tool vibration and its influence upon surface
           generation in ultra-precision machining
    • Abstract: Publication date: April 2015
      Source:International Journal of Machine Tools and Manufacture, Volume 91
      Author(s): S.J. Zhang , S. To , G.Q. Zhang , Z.W. Zhu
      Vibration in ultra-precision machining (UPM) is an intrinsic physical phenomenon, which is a key factor influencing surface generation. With a focus on passive vibration, this paper reviews the latest research into vibration characteristics and the effect of vibration on surface generation in UPM. The opportunities and challenges facing researchers are also discussed and suggestions are made for future related studies. It is found that active vibration can possibly be employed to improve surface quality influenced by passive vibration in UPM.
      Graphical abstract image

      PubDate: 2015-05-16T02:09:09Z
       
  • Surface plastic deformation and surface topography prediction in
           peripheral milling with variable pitch end mill
    • Abstract: Publication date: April 2015
      Source:International Journal of Machine Tools and Manufacture, Volume 91
      Author(s): Dong Yang , Zhanqiang Liu
      Peripheral milling with variable pitch end mills is available to improve the surface integrity during final machining. Among the indicators of surface integrity, surface plastic deformation and surface topography are the foremost characteristics. In this paper, two main aspects are included. On the one hand, a unique generic technique in terms of depth of plastic deformation, plastic strains distribution for analyzing the plastic deformations on the work piece is presented. The presented technique applies the problem of the Flamant–Boussinesq in the plastic deformation problem. Through experimental verification, the analytical results have a higher accuracy. On the other hand, the surface generation mechanism in peripheral milling with variable pitch end mills is studied. Corresponding surface generation model, which is used to predict the generated surface topography with incorporating the cutting process parameters and several sources of machining error such as tilting, run-out, deflection of the tool and work piece displacement, is proposed. Through a set of cutting tests, it is confirmed that the presented model predicts the surface texture and roughness parameters precisely. By the sensitivity analysis, Helix angle and feed rate have significant influences on surface topography, while the effects of cutting speed on surface topography can be neglected when the effects of the machining error sources on the behavior and performance of the model are not considered. Among the sources of machining errors, the deflection of the tool has the most significant impact on the surface profile. The sequence is the displacement of the work piece and the run-out of the tool.


      PubDate: 2015-05-16T02:09:09Z
       
  • Model predictive control to mitigate chatters in milling processes with
           input constraints
    • Abstract: Publication date: April 2015
      Source:International Journal of Machine Tools and Manufacture, Volume 91
      Author(s): Hai-Tao Zhang , Yue Wu , Defeng He , Huan Zhao
      Due to the rigidity-flexibility coupling and self-excitation mechanism, chatters are often encountered in machining processes. They severely limit the productive capacity of machine tools, and lead to inferior work piece quality, cutting disturbances and quick tool wear. In recent years, the increasing industrial demand of high quality and high efficiency machining motivates us to develop a niche active control method to mitigate the chatter dynamics with input constraints. In this work, an active model predictive control (MPC) method for the milling process is developed such that the chatter-free domain of stable operation is substantially enlarged and a higher efficiency can be thus achieved. Therein, the complex perturbation dynamics including time-delay and periodical excitation is transformed into a linear time-varying (LTI) system, and afterwards both model-based prediction and receding horizon optimization are implemented by the proposed MPC scheme to address the system uncertainties and input constraints to guarantee the chatter-free stability and feasibility. Effectiveness and superiority of the proposed MPC are finally demonstrated by means of illustrative examples.


      PubDate: 2015-05-16T02:09:09Z
       
  • An investigation of energy loss mechanisms in water-jet assisted
           underwater laser cutting process using an analytical model
    • Abstract: Publication date: April 2015
      Source:International Journal of Machine Tools and Manufacture, Volume 91
      Author(s): Suvradip Mullick , Yuvraj K. Madhukar , Subhransu Roy , Ashish K. Nath
      The water-jet assisted underwater laser cutting processes has relatively low overall efficiency compared to gas assisted laser cutting process due to high convective loss in water-jet from the hot melt layer and scattering loss of laser radiation by the water vapour formed at the laser–workpiece–water interaction region. However, the individual contribution of different losses and their dependency on process parameters are not fully investigated. Therefore, a lumped parameter analytical model for this cutting process has been formulated considering various laser–material–water interaction phenomena, different loss mechanisms and shear force provided by the water-jet, and has been used to predict various output parameters including the maximum cutting speed, cut front temperature, cut kerf and the loss of laser power through different mechanisms as functions of laser power and water-jet speed. The predictions of cutting speed, kerf-width and cut front temperature were validated with the experimental results. The modeling revealed that the scattering in water vapour is the dominant loss mechanism, causing ~40–50% of laser power loss. This also predicted that the percentage losses are lower for higher laser powers and lower water-jet speeds. In order to minimize the deleterious effect of vapour, dynamics of its formation due to laser heating and its removal by water-jet was experimentally studied. And, the cutting was done with modulated power laser beam of different pulse on- and off-times to determine the pulse on-time sufficiently short to disallow growth of vapour layer, still cutting be effected and the off-time enough long for water-jet to remove the vapour layer from the interaction zone before next pulse arrives. Compared to CW laser beam the modulated laser beam of same average power yielded higher process efficiency.


      PubDate: 2015-05-16T02:09:09Z
       
  • A review of surface roughness generation in ultra-precision machining
    • Abstract: Publication date: April 2015
      Source:International Journal of Machine Tools and Manufacture, Volume 91
      Author(s): S.J. Zhang , S. To , S.J. Wang , Z.W. Zhu
      Ultra-precision machining (UPM) is capable of manufacturing a high quality surface at a nanometric surface roughness. For such high quality surface in a UPM process, due to the machining complexity any variable would be possible to deteriorate surface quality, consequently receiving much attention and interest. The general factors are summarized as machine tool, cutting conditions, tool geometry, environmental conditions, material property, chip formation, tool wear, vibration etc. This paper aims to review the current state of the art in studying the surface roughness formation and the factors influencing surface roughness in UPM. Firstly, the surface roughness characteristics in UPM is introduced. Then in UPM, a wide variety of factors for surface roughness are then reviewed in detail and the mechanism of surface roughness formation is concluded thoroughly. Finally, the challenges and opportunities faced by industry and academia are discussed and several principle conclusions are drawn.
      Graphical abstract image

      PubDate: 2015-05-16T02:09:09Z
       
  • Analytical curvature-continuous dual-Bézier corner transition for
           five-axis linear tool path
    • Abstract: Publication date: April 2015
      Source:International Journal of Machine Tools and Manufacture, Volume 91
      Author(s): QingZhen Bi , Jing Shi , YuHan Wang , LiMin Zhu , Han Ding
      A novel analytical five-axis path-smoothing algorithm is developed for the high speed machining of a linear five-axis tool path. Segment junctions of the linear tool path in the machine tool coordinate system, which are tangent-discontinuous points, are all blended by two transition cubic Bézier curves. One cubic Bézier curve is used to smooth the segment junction of the translational path, and the other Bézier curve is used to smooth the segment junction of the rotational path. The tangency and curvature continuities are both guaranteed in the new path. The dual-Bézier transition algorithm has three advantages: (1) Compared with the path-smoothing method in the workpiece coordinate system, the new dual-Bézier transition method directly and simultaneously smooths the machine tool axis trajectories of both translational path and rotational path. The feed speed and stability will both be improved because the tool path discontinuities are the most important source of feed fluctuation. (2) The constraints of approximation error and the synchronization of parametrization of two smoothed curves, which are the most challenging problems in the smoothing of 5-axis tool path, are both considered. (3) The transition cubic Bézier curve pair has an analytical solution and can be easily integrated in the real-time interpolator. Computational examples and the cutting experiment of an impeller blade show that the novel path-smoothing method has obvious advantages in both feed smoothness and cutting efficiency over the original linear interpolator.


      PubDate: 2015-05-16T02:09:09Z
       
  • Identification of two different geometric error definitions for the rotary
           axis of the 5-axis machine tools
    • Abstract: Publication date: April 2015
      Source:International Journal of Machine Tools and Manufacture, Volume 91
      Author(s): Nuodi Huang , Qingzhen Bi , Yuhan Wang
      Geometric errors are clearly among the critical error sources in 5-axis machine tools and directly contribute to the machining inaccuracies. According to the definition of geometric errors of the rotary axis, different understandings have been exist in published studies. It is extremely dangerous as it makes the comprehension of the geometric errors ambiguous and may make the geometric error identification and compensation less effective. This phenomenon has not been noticed so far. In this paper, two different commonly used geometric error definition and modeling methods are firstly identified and analyzed, named as “Rotary axis component shift” and “Rotary axis line shift”. The features and relationships of these two error modeling methods are analyzed. After a detailed comparison, “Rotary axis component shift” is more suitable to definite the geometric errors of rotary axis. An experiment has been conducted on a 5-axis machine tool to show the correctness of our work. The results show that the identified geometric errors of rotary axis based on the two error models are greatly different and need to be concerned.


      PubDate: 2015-05-16T02:09:09Z
       
  • Corrigendum to: “Threshold tool-radius condition maximizing the
           formability in SPIF considering a variety of materials: Experimental and
           FE investigations” [Int. J. Mach. Tools Manuf. 88 (2015)
           82–94]
    • Abstract: Publication date: April 2015
      Source:International Journal of Machine Tools and Manufacture, Volume 91
      Author(s): K.A. Al-Ghamdi , G. Hussain



      PubDate: 2015-05-16T02:09:09Z
       
  • IFC - Editorial board
    • Abstract: Publication date: March 2015
      Source:International Journal of Machine Tools and Manufacture, Volume 90




      PubDate: 2015-05-16T02:09:09Z
       
  • The interactive effects on deformation behavior in laser thermal
           adjustment of two-bridge actuators
    • Abstract: Publication date: March 2015
      Source:International Journal of Machine Tools and Manufacture, Volume 90
      Author(s): Hong Shen , Jun Hu , Zhenqiang Yao
      Laser thermal adjustment of two-bridge actuators by heating one bridge attracts much attention. However, the interactive influence of heating two bridges on the in-plane and out-of-plane deformations of actuators has not been explored. In this study, a 3D thermo-mechanical analysis is conducted to study the laser thermal adjustment of actuators under heating two bridges. The effects of the time gap between the heating two bridges on temperature, stress distribution and deformation behavior are investigated. The results show that there are some interactions between stress and temperature in the two heating bridges, which can significantly affect the deformations of actuators. To validate the present numerical model experimental work is also performed and reported in the paper.


      PubDate: 2015-05-16T02:09:09Z
       
 
 
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