Subjects -> ENGINEERING (Total: 2688 journals)
    - CHEMICAL ENGINEERING (229 journals)
    - CIVIL ENGINEERING (237 journals)
    - ELECTRICAL ENGINEERING (176 journals)
    - ENGINEERING (1325 journals)
    - ENGINEERING MECHANICS AND MATERIALS (452 journals)
    - HYDRAULIC ENGINEERING (56 journals)
    - INDUSTRIAL ENGINEERING (98 journals)
    - MECHANICAL ENGINEERING (115 journals)

ENGINEERING (1325 journals)            First | 1 2 3 4 5 6 7 | Last

Showing 601 - 800 of 1205 Journals sorted alphabetically
International Journal of Quality Assurance in Engineering and Technology Education     Full-text available via subscription   (Followers: 3)
International Journal of Quality Engineering and Technology     Hybrid Journal   (Followers: 4)
International Journal of Quantum Information     Hybrid Journal   (Followers: 6)
International Journal of Rapid Manufacturing     Hybrid Journal   (Followers: 3)
International Journal of Recent Contributions from Engineering, Science & IT     Open Access  
International Journal of Reliability, Quality and Safety Engineering     Hybrid Journal   (Followers: 14)
International Journal of Renewable Energy Technology     Hybrid Journal   (Followers: 8)
International Journal of Robust and Nonlinear Control     Hybrid Journal   (Followers: 10)
International Journal of Science and Innovative Technology     Open Access  
International Journal of Science Engineering and Advance Technology     Open Access  
International Journal of Sediment Research     Full-text available via subscription   (Followers: 2)
International Journal of Self-Propagating High-Temperature Synthesis     Hybrid Journal  
International Journal of Service Science, Management, Engineering, and Technology     Full-text available via subscription   (Followers: 2)
International Journal of Signal and Imaging Systems Engineering     Hybrid Journal  
International Journal of Six Sigma and Competitive Advantage     Hybrid Journal   (Followers: 4)
International Journal of Social Robotics     Hybrid Journal   (Followers: 3)
International Journal of Software Engineering and Knowledge Engineering     Hybrid Journal   (Followers: 6)
International Journal of Space Science and Engineering     Hybrid Journal   (Followers: 13)
International Journal of Speech Technology     Hybrid Journal   (Followers: 7)
International Journal of Spray and Combustion Dynamics     Full-text available via subscription   (Followers: 15)
International Journal of Student Project Reporting     Hybrid Journal   (Followers: 4)
International Journal of Surface Engineering and Interdisciplinary Materials Science     Full-text available via subscription   (Followers: 1)
International Journal of Surface Science and Engineering     Hybrid Journal   (Followers: 6)
International Journal of Sustainable Engineering     Hybrid Journal   (Followers: 4)
International Journal of Sustainable Lighting     Open Access  
International Journal of Sustainable Manufacturing     Hybrid Journal   (Followers: 4)
International Journal of Systems and Service-Oriented Engineering     Full-text available via subscription  
International Journal of Systems Assurance Engineering and Management     Hybrid Journal  
International Journal of Systems, Control and Communications     Hybrid Journal   (Followers: 6)
International Journal of Technoethics     Full-text available via subscription   (Followers: 2)
International Journal of Technology Management and Sustainable Development     Hybrid Journal   (Followers: 1)
International Journal of Technology Policy and Law     Hybrid Journal   (Followers: 6)
International Journal of Telemedicine and Applications     Open Access   (Followers: 4)
International Journal of Thermal Sciences     Hybrid Journal   (Followers: 18)
International Journal of Thermodynamics     Open Access   (Followers: 15)
International Journal of Transportation Engineering     Open Access   (Followers: 2)
International Journal of Turbomachinery, Propulsion and Power     Open Access   (Followers: 23)
International Journal of Ultra Wideband Communications and Systems     Hybrid Journal  
International Journal of Vehicle Autonomous Systems     Hybrid Journal  
International Journal of Vehicle Design     Hybrid Journal   (Followers: 6)
International Journal of Vehicle Information and Communication Systems     Hybrid Journal   (Followers: 1)
International Journal of Vehicle Noise and Vibration     Hybrid Journal   (Followers: 6)
International Journal of Vehicle Safety     Hybrid Journal   (Followers: 3)
International Journal of Virtual Technology and Multimedia     Hybrid Journal   (Followers: 2)
International Journal of Wavelets, Multiresolution and Information Processing     Hybrid Journal  
International Journal on Artificial Intelligence Tools     Hybrid Journal   (Followers: 9)
International Journal on Smart Sensing and Intelligent Systems     Open Access  
International Nano Letters     Open Access   (Followers: 6)
International Review of Applied Sciences and Engineering     Full-text available via subscription  
International Scholarly Research Notices     Open Access   (Followers: 121)
International Scientific and Vocational Studies Journal     Open Access  
International Scientific Journal of Engineering and Technology (ISJET)     Open Access  
Inventions     Open Access  
Inventum     Open Access  
Inverse Problems in Science and Engineering     Hybrid Journal   (Followers: 3)
Investiga : TEC     Open Access  
Ionics     Hybrid Journal   (Followers: 2)
IPTEK The Journal for Technology and Science     Open Access  
Iranian Journal of Optimization     Open Access   (Followers: 2)
Iranian Journal of Science and Technology, Transactions A : Science     Hybrid Journal  
IRBM News     Full-text available via subscription  
Ironmaking & Steelmaking     Hybrid Journal   (Followers: 4)
ISA Transactions     Full-text available via subscription  
ISSS Journal of Micro and Smart Systems     Hybrid Journal   (Followers: 3)
IT Professional     Full-text available via subscription   (Followers: 24)
Iteckne     Open Access  
J-ENSITEC : Journal Of Engineering and Sustainable Technology     Open Access   (Followers: 4)
Johnson Matthey Technology Review     Open Access  
Journal of Advanced College of Engineering and Management     Open Access  
Journal of Advanced Joining Processes     Open Access  
Journal of Advanced Manufacturing Systems     Hybrid Journal   (Followers: 5)
Journal of Aerodynamics     Open Access   (Followers: 27)
Journal of Aerosol Science     Hybrid Journal   (Followers: 7)
Journal of Aerospace Engineering     Full-text available via subscription   (Followers: 66)
Journal of Alloys and Compounds     Hybrid Journal   (Followers: 16)
Journal of Analytical and Applied Pyrolysis     Hybrid Journal   (Followers: 5)
Journal of Analytical Science & Technology     Open Access   (Followers: 4)
Journal of Analytical Sciences, Methods and Instrumentation     Open Access   (Followers: 4)
Journal of Applied Engineering Sciences     Open Access  
Journal of Applied Physics     Hybrid Journal   (Followers: 69)
Journal of Applied Research and Technology     Open Access  
Journal of Applied Science and Technology     Full-text available via subscription   (Followers: 1)
Journal of Applied Sciences     Open Access   (Followers: 4)
Journal of Architectural and Engineering Research     Open Access   (Followers: 3)
Journal of Architectural Engineering     Full-text available via subscription   (Followers: 4)
Journal of Automation and Control     Open Access   (Followers: 9)
Journal of Aviation Technology and Engineering     Open Access   (Followers: 10)
Journal of Biological Dynamics     Open Access   (Followers: 1)
Journal of Biomedical Science     Open Access   (Followers: 4)
Journal of Biomolecular NMR     Hybrid Journal   (Followers: 6)
Journal of Biosciences     Open Access   (Followers: 1)
Journal of Building Pathology and Rehabilitation     Hybrid Journal  
Journal of Catalysis     Hybrid Journal   (Followers: 11)
Journal of Catalyst & Catalysis     Full-text available via subscription   (Followers: 2)
Journal of Central South University     Hybrid Journal   (Followers: 1)
Journal of Chemical and Petroleum Engineering     Open Access   (Followers: 1)
Journal of China Coal Society     Open Access  
Journal of China Universities of Posts and Telecommunications     Full-text available via subscription  
Journal of Cleaner Production     Hybrid Journal   (Followers: 27)
Journal of Coastal and Riverine Flood Risk (JCRFR)     Open Access   (Followers: 1)
Journal of Cold Regions Engineering     Full-text available via subscription   (Followers: 3)
Journal of Combinatorial Designs     Hybrid Journal   (Followers: 4)
Journal of Combustion     Open Access   (Followers: 40)
Journal of Computational and Nonlinear Dynamics     Full-text available via subscription   (Followers: 6)
Journal of Computational and Theoretical Nanoscience     Full-text available via subscription  
Journal of Computational Biology     Hybrid Journal   (Followers: 9)
Journal of Computational Design and Engineering     Open Access   (Followers: 1)
Journal of Computational Electronics     Hybrid Journal   (Followers: 5)
Journal of Computational Multiphase Flows     Open Access   (Followers: 1)
Journal of Computing and Information Science in Engineering     Full-text available via subscription   (Followers: 1)
Journal of Coupled Systems and Multiscale Dynamics     Full-text available via subscription  
Journal of Dairy Science     Open Access   (Followers: 12)
Journal of Delta Urbanism     Open Access   (Followers: 2)
Journal of Display Technology     Hybrid Journal   (Followers: 3)
Journal of Dynamic Systems, Measurement, and Control     Full-text available via subscription   (Followers: 14)
Journal of Dynamical and Control Systems     Hybrid Journal   (Followers: 7)
Journal of Earthquake Engineering     Hybrid Journal   (Followers: 14)
Journal of Elasticity     Hybrid Journal   (Followers: 7)
Journal of Electroceramics     Hybrid Journal  
Journal of Electromagnetic Waves and Applications     Hybrid Journal   (Followers: 10)
Journal of Electronic Testing     Hybrid Journal   (Followers: 2)
Journal of Electronics Cooling and Thermal Control     Open Access   (Followers: 9)
Journal of Electrostatics     Hybrid Journal   (Followers: 2)
Journal of Energy Engineering     Full-text available via subscription   (Followers: 7)
Journal of Energy Resources Technology     Full-text available via subscription   (Followers: 4)
Journal of Engineering     Open Access  
Journal of Engineering     Open Access   (Followers: 1)
Journal of Engineering and Applied Science     Open Access  
Journal of Engineering and Technological Sciences     Open Access   (Followers: 2)
Journal of Engineering Design     Hybrid Journal   (Followers: 17)
Journal of Engineering Education     Hybrid Journal   (Followers: 7)
Journal of Engineering for Gas Turbines and Power     Full-text available via subscription   (Followers: 15)
Journal of Engineering Mathematics     Hybrid Journal   (Followers: 2)
Journal of Engineering Mechanics     Full-text available via subscription   (Followers: 16)
Journal of Engineering Physics and Thermophysics     Hybrid Journal   (Followers: 2)
Journal of Engineering Research     Open Access   (Followers: 1)
Journal of Engineering Research and Reports     Open Access  
Journal of Engineering Technology and Applied Sciences     Open Access  
Journal of Engineering Thermophysics     Hybrid Journal   (Followers: 4)
Journal of Engineering, Design and Technology     Hybrid Journal   (Followers: 17)
Journal of Engineering, Project, and Production Management     Open Access  
Journal of Environmental & Engineering Geophysics     Hybrid Journal   (Followers: 2)
Journal of Environmental Engineering     Full-text available via subscription   (Followers: 49)
Journal of Environmental Engineering and Landscape Management     Open Access   (Followers: 8)
Journal of Environmental Engineering and Science     Hybrid Journal   (Followers: 2)
Journal of Experimental Nanoscience     Hybrid Journal  
Journal of Fire Sciences     Hybrid Journal   (Followers: 6)
Journal of Flood Risk Management     Hybrid Journal   (Followers: 14)
Journal of Flow Control, Measurement & Visualization     Open Access   (Followers: 1)
Journal of Fluids Engineering     Full-text available via subscription   (Followers: 30)
Journal of Fourier Analysis and Applications     Hybrid Journal   (Followers: 3)
Journal of Fuel Cell Science and Technology     Full-text available via subscription   (Followers: 2)
Journal of Functional Analysis     Full-text available via subscription   (Followers: 3)
Journal of Fundamental and Applied Sciences     Open Access  
Journal of Geological Research     Open Access   (Followers: 1)
Journal of Geotechnical and Geoenvironmental Engineering     Full-text available via subscription   (Followers: 30)
Journal of Geotechnical Engineering     Full-text available via subscription   (Followers: 4)
Journal of Geovisualization and Spatial Analysis     Hybrid Journal  
Journal of Global Optimization     Hybrid Journal   (Followers: 6)
Journal of Graduate School of Natural and Applied Sciences of Mehmet Akif Ersoy University     Open Access  
Journal of Hazardous Materials Advances     Open Access  
Journal of Healthcare Engineering     Open Access   (Followers: 3)
Journal of Heat Transfer     Full-text available via subscription   (Followers: 66)
Journal of Humanitarian Engineering     Open Access   (Followers: 1)
Journal of Hydraulic Engineering     Full-text available via subscription   (Followers: 27)
Journal of Hyperspectral Remote Sensing     Open Access   (Followers: 23)
Journal of Imaging     Open Access   (Followers: 3)
Journal of Industrial and Production Engineering     Hybrid Journal   (Followers: 4)
Journal of Industrial Engineering and Management     Open Access   (Followers: 5)
Journal of Industrial Safety Engineering     Full-text available via subscription   (Followers: 6)
Journal of Inequalities and Applications     Open Access  
Journal of Infrared, Millimeter and Terahertz Waves     Hybrid Journal   (Followers: 3)
Journal of Infrastructure Preservation and Resilience     Open Access   (Followers: 1)
Journal of Institute of Science and Technology     Open Access  
Journal of Intelligent and Connected Vehicles     Open Access   (Followers: 1)
Journal of Intelligent Systems : Theory and Applications     Open Access  
Journal of International Maritime Safety, Environmental Affairs, and Shipping     Open Access   (Followers: 1)
Journal of Iron and Steel Research International     Hybrid Journal   (Followers: 7)
Journal of Irrigation and Drainage Engineering     Full-text available via subscription   (Followers: 24)
Journal of King Saud University - Engineering Sciences     Open Access  
Journal of KONBiN     Open Access   (Followers: 4)
Journal of Liquid Chromatography & Related Technologies     Hybrid Journal   (Followers: 7)
Journal of Management in Engineering     Full-text available via subscription   (Followers: 9)
Journal of Manufacturing Science and Engineering     Full-text available via subscription   (Followers: 32)
Journal of Manufacturing Systems     Full-text available via subscription   (Followers: 3)
Journal of Manufacturing Technology Management     Hybrid Journal   (Followers: 3)
Journal of Mechanical Design and Testing     Open Access   (Followers: 4)
Journal of Mechatronics     Full-text available via subscription   (Followers: 3)
Journal of Mega Infrastructure & Sustainable Development     Hybrid Journal  
Journal of Metallurgy     Open Access   (Followers: 8)
Journal of Mining Institute     Open Access  
Journal of Motor Behavior     Hybrid Journal   (Followers: 8)
Journal of Multivariate Analysis     Hybrid Journal   (Followers: 15)
Journal of Nanoengineering and Nanomanufacturing     Full-text available via subscription  
Journal of Nanoparticle Research     Hybrid Journal   (Followers: 3)
Journal of Nanoscience     Open Access  
Journal of Nanoscience and Nanotechnology     Full-text available via subscription   (Followers: 8)
Journal of NanoScience, NanoEngineering & Applications     Full-text available via subscription  
Journal of Nanotechnology     Open Access   (Followers: 10)
Journal of Nanotechnology in Engineering and Medicine     Full-text available via subscription   (Followers: 4)

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Similar Journals
Journal Cover
International Journal of Precision Engineering and Manufacturing
Number of Followers: 8  
 
  Hybrid Journal Hybrid journal (It can contain Open Access articles)
ISSN (Print) 2234-7593 - ISSN (Online) 2005-4602
Published by Springer-Verlag Homepage  [2469 journals]
  • Influence of Thermal Processing Conditions on Mechanical and Material
           Properties of 3D Printed Thin-Structures Using PEEK Material

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      Abstract: Poly-ether-ether-ketone (PEEK) was one of the most promising engineering plastics, which had been widely employed in the aerospace, biomedical and automotive industry and manufacturing. The design of various 3D printing (3DP) parameters had a significant impact on its mechanical and thermal properties. This study aimed to investigate the thermodynamic properties of thin-structure PEEK samples by printing them under various conditions, including varying substrate and ambient temperature parameters, under a control- method. Numerous critical properties such as interlayer bonding force, tensile and bending properties, dynamic mechanical properties, and crystallization had been investigated in this work. The results indicated that the maximum relative interlayer bonding force was 989.91 N, while comparing to the lowest initial ambient and substrate temperature 60 °C and 90 °C, the optimal tensile and bending strengths both increased by 28.46% and 13.86% to 86.62 MPa and 113.21 MPa under ambient and substrate temperature 90 °C and 160 °C, respectively. Concurrently, the crystallinity increased by 6.67% to 31.56%. Mechanical and thermal properties had been significantly improved when appropriate substrate temperature parameters were used during the printing process, demonstrating the enormous potential in printing PEEK material. Thermal processing was another critical factor in achieving higher performance of 3D printing PEEK components.
      PubDate: 2022-05-09
       
  • Fabrication and Properties of Mo2FeB2 Cermet Coating on Stainless Steel
           Surface via One-Step Forming Technology of Powder Metallurgy

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      Abstract: Abstract Mo2FeB2 cermet coating and stainless steel substrate were integrally fabricated by one-step forming technology of powder metallurgy. The phase and microstructure of the coating and interface were analysed through X-ray diffraction and scanning electron microscopy. Microhardness, bending strength, and wear resistance were also measured by Vickers tester, the electronic universal testing machine and wear tester. The microstructure of Mo2FeB2 cermet coating showed Mo2FeB2 hard phase and Fe binder phase, which was uniform and dense. A compacted interface without pores or defects was formed between the cermet coating and stainless steel substrate. The formation of eutectic liquid phase and applied pressure in sintering process promoted densification of the coating. Mo2FeB2 cermet coating presented a microhardness of 1275 HV200, which was obviously higher than that of 316L stainless steel substrate. The results of three-point bending test and wear test showed that Mo2FeB2 cermet coating on steel substrate maintained good metallurgical interface bonding with the substrate, and the coating exhibited high bending strength and excellent wear resistance.
      PubDate: 2022-05-04
       
  • Identifying Abnormal CFRP Holes Using Both Unsupervised and Supervised
           Learning Techniques on In-Process Force, Current, and Vibration Signals

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      Abstract: Abstract This study aims to conduct abnormality detection by applying machine learning algorithms when drilling a carbon fiber reinforced plastic laminate. In-process signals including current, thrust force, and vibration were captured during the dry drilling experiments using a 6 mm physical vapor deposit diamond-coated drill at the consistent spindle speed of 6500 RPM and 0.05 mm/rev. Across measurements from out-of-process variables, including hole diameter, roundness, surface roughness, entry/exit delamination, and entry/exit uncut fiber area, in-process measurements were most able to find outliers with respect to diameter. Both Principal Component Analysis, an unsupervised dimensionality reduction technique, and Linear Discriminant Analysis, a supervised dimensionality reduction technique, could separate oversize or undersize holes from average-sized holes when using fast Fourier transformation data of in-process vibration. Predictive performance with k-Nearest Neighbors shows that our machine learning pipeline can predict oversized vs. non-oversized holes with over 85% accuracy in this dataset. Peak prediction performance is obtained when in-process measurement data is viewed from the frequency domain, and predictions are weighted based on the relative distances of the nearest neighbors.
      PubDate: 2022-05-03
       
  • A Dual Difference Method for Identification of the Inherent Spindle Axis
           Parallelism Errors of Machine Tools

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      Abstract: Abstract It is essential to identify spindle axis parallelism errors because such errors trigger volumetric errors when tools of different lengths are used. However, only a few works have addressed this issue. Thus, we identified the inherent spindle axis parallelism errors of machine tools relative to the end-point reference straight line of the Z-axis (according to ISO 230-1) using a dual difference method. Here, “inherent” refers to parallelism errors of the spindle axis that are not affected by the geometric errors of other axes controlled during the measurements, and “dual difference” refers to the difference in the differences of measuring data. The dual difference method uses two pairs of circular tests performed with the aid of a double ball-bar (DBB); the tool lengths differ during each test and the DBB set-up is shared by the pairs. Parallelism errors are then identified based on the dual differences within and between the two pairs. Experimentally, the maximum peak-to-valley (PV) values were 54.5 and 48.7 μm for differences in radial deviations within the two pairs when the parallelism errors were not compensated. After tool-center-point compensation by the identified errors, the PV values improved to 8.0 and 9.2 μm, respectively, showing that compensation was successful. In addition, the concentricity of two holes machined using tools of different lengths improved from 31.2 μm without compensation to 15.9 μm with compensation, further demonstrating the effectiveness of the method.
      PubDate: 2022-05-02
       
  • User Intention Based Intuitive Mobile Platform Control: Application to a
           Patient Transfer Robot

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      Abstract: Abstract This study proposes a user’s intuitive intention-based control system for mobile robot platforms. As an application of the control scheme, we focused on a robot that transports patients in medical facilities. However, since most of the people who operate the patient transfer robot (PTR) are not robotics experts, an intuitive control method is needed to enable easy operation of the robot system. Also minimizing the discomfort experienced by the patient in the process of transferring the patient through the patient transfer robot is another important issue to consider. Therefore, the main contributions of this are developing an intuitive user interface and proposing a sway reduction control scheme. To accomplish the first issue, the intuitive control is implemented by proposing a robot control interface, where four force-sensing resistor (FSR) sensors are installed on a robot’s handle (where a user holds a robot). Through this, the robot can be easily moved with only a simple and intuitive operation of the user. Therefore forward, backward, left movement, right movement, left turn, and right turn operation can be controlled through the intuitive movement of the user input through the developed user interface. Additionally, in order to satisfy the second requirement, the patient’s sway reduction strategy is suggested by applying fuzzy logic-based control command generation method to the user intention. Through this method, the sway that occurs during the movement of the robot is reduced. In this study, the mecanum wheel was applied to the driving platform of the patient transfer robot to enable omnidirectional movement. The performance of the proposed control method is verified through simulations and experiments. Simulation and experimental results confirm that the proposed method reduced the acceleration and jerk root mean square values of the robot compared to a comparison method.
      PubDate: 2022-05-02
       
  • Operating Cost Savings in the Atomic Layer Deposition Process of Ultrathin
           Electrolyte for Solid Oxide Fuel Cells by Applying Oxygen Plasma

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      Abstract: Abstract The impact of operating cost savings in a plasma-enhanced atomic layer deposition (P-ALD) process to fabricate the ultrathin yttria-stabilized zirconia (YSZ) electrolyte for low-temperature solid oxide fuel cells is quantitatively evaluated by comparison with a thermal atomic layer deposition (T-ALD) process considering the two cost factors: (1) operating costs of power consumption and precursor/gas usages and (2) capital costs of plasma generator installations. Because of lower precursor/gas usages and lower power consumption of the P-ALD YSZ process, it is evaluated that the specific operating costs of the P-ALD YSZ process is ~ 47% lower than that of the T-ALD YSZ process. For annual production of 2.6 kW fuel cell systems of 100 units, it is estimated that the cumulative cost savings of the P-ALD YSZ process versus the T-ALD YSZ process amounts to $678,000 in the fifth year.
      PubDate: 2022-05-01
       
  • Realization of Enhanced Mechanical Properties of Solid-State Welded Ti
           Alloy with Commercial Purity

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      Abstract: Abstract In this study, we investigated the solid-state weldability of Ti alloys with commercial purity (grade 2). First, as a solid-state welding approach, we conducted friction welding at a rotation speed of 1600 rpm and a friction pressure of 15 kgf on rod-type specimens with a size of 15 mm (dia.) × 50 mm (length). Subsequently, the grain boundary characteristic distributions such as the grain size, shape, orientation, and misorientation angle of the welds were clarified by means of the electron backscatter diffraction method. To study the mechanical properties of the welds, we conducted Vickers microhardness and tensile tests. We found that the application of friction welding to Ti alloy led to a significantly refined grain size in the weld zone (0.84 μm) relative to that in the base material (11.4 μm), accompanied by an orientation change from <0001> in the base material to <2–1–10> in the weld zone. In addition, the mechanical properties of the welds were more enhanced than those of the base material: the microhardness and yield strength of the weld were approximately 20% and 2% higher, respectively, than those of base material. These enhanced mechanical properties are mainly due to grain refinement and orientation development during welding.
      PubDate: 2022-05-01
       
  • Investigation on Spraying Uniformity in Etching Process of FPCB with
           18 μm Line Pitch

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      Abstract: Abstract In the wet etching process of the flexible printed circuit board (FPCB), to obtain a symmetrical and stable circuit structure and improve the yield, it is necessary to control the uniformity of the etchant velocity and pressure on the surface of the FPCB as far as possible. In this paper, a numerical method implemented with Euler multiphase flow model is proposed to study the spraying uniformity of the wet etching process of the FPCB. A 3D full model of the multi-nozzle array is established to study the velocity distribution of the etchant in the spraying domain. The FPCB sample is manufactured based on the process parameters obtained by the parametric study. In the experiment, pressure sensors are applied to monitor the etchant pressure on the surface of the FPCB and the cross-section of the FPCB circuit is observed, which validates the numerical simulation method. The results of simulations demonstrate that when the nozzle rotation angle θ is 1.3°, the distribution of the low-speed flow zone on the surface of the FPCB is about 60 mm along the X axis direction, and the standard deviation of the pressure is reduced by 67.6% compared to 0°. The cross-section of the FPCB circuit is close to an isosceles trapezoid with an 18 μm line pitch, which is the center-to-center distance between the adjacent circuit lines.
      PubDate: 2022-05-01
       
  • Optimization: Drone-Operated Metal Detection Based on Machine Learning and
           PID Controller

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      Abstract: Abstract This paper proposes a methodology to detect metals using a drone equipped with a metal detector and programmed by machine learning (ML) models. Our proposed research process could be considered a safe and efficient unmanned mine detection technology for the eventual removal of landmines. Users of this methodology can remotely control the drones without entering the minefield to detect the metal buried and to distinguish whether the metal is mine or not. To realize this idea, we have first stabilized and improved the attitude control of a drone with an attached metal detector by using the micro genetic algorithm-based optimization of proportional–integral–differential control gains. Next, for metal detection, ML models such as a support vector machine and a back-propagation neural network were trained using the annotated dataset. Finally, we have built a controlled drone equipped with a metal detector and trained ML models and experimentally validated our methodology. According to the experimental results, the present study secured the flight stability of the unmanned metal detection drones and the high detection success rate.
      PubDate: 2022-05-01
       
  • Error Compensation Through Analysis of Force and Deformation in
           Non-circular Grinding

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      Abstract: Abstract With industrial advancement, the demand for precision parts is increasing. A crankshaft is the main part of an engine, which determines the life and quality of the engine, and is one of the precision parts whose demand is growing. Non-circular grinding is the grinding method used for crankshafts, and it is different from conventional grinding methods. In this study, the grinding force, considering the characteristics of the non-circular grinding, was obtained, and the bending and torsional deformation of the crankshaft caused by the grinding force was predicted. By applying the deformation to the grinding force, a real depth of the cut prediction model that can calculate the grinding force and predict the real depth of cut was proposed. A compensation model that can estimate the set depth of cut was proposed to obtain the desired real depth of cut. Various grinding characteristics related to force and deformation in non-circular grinding were analyzed. It was observed that the grinding force has different values at all grinding points, even if one pin is ground because the change in the workpiece velocity depends on the grinding point. Unlike in general grinding, the tangential force affects the depth of cut. The real depth of cut obtained through the prediction model proposed in this study differed from the set depth of cut by up to 45%. Comparing the compensation model of this study to the conventional method, the former showed approximately 20% improved compensation performance.
      PubDate: 2022-04-27
       
  • Design and Validation of a Passive Motion Scaling Mechanism Prototype for
           Microsurgery

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      Abstract: Abstract Since the advent of the commercial da Vinci surgical system, microsurgical robotic systems have been increasingly investigated. These systems improve the accuracy and dexterity of surgeries using a computerized motion scaling function between a surgeon’s hand and surgical instrument. However, the manufacturing process of these systems is expensive owing to the use of multiple sensors, actuators, and controllers. Additionally, certain limitations exist, such as an increase in the size of the operating room to accommodate the robotic system and the absence of tactile force feedback. To address these problems, we propose a passive motion scaling mechanism for microsurgery. Based on the pantograph mechanism, we downscale the linear displacement of the surgeon’s hand and transfer it to the surgical instrument. Furthermore, the rotational displacement of the surgeon’s hand in an actual surgery is transmitted to the surgical instrument on a 1:1 scale by applying a parallelogram mechanism. We designed and fabricated a prototype capable of transmitting linear and rotational displacements (pitch and yaw) of the surgeon’s hand with three degrees of freedom (DOFs) and two DOFs, respectively, by combining the two mechanisms. The obtained experimental results verify the motion scaling function of the developed prototype.
      PubDate: 2022-04-25
       
  • Development of a Variable Stiffness Modulating Mechanism Based on
           Phase-Change Material and a Temperature Control System

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      Abstract: Abstract One of the challenges of using an endoscopic robot for natural orifice transluminal endoscopic surgery (NOTES) is the ability to adjust its joint stiffness. The endoscopic robot joint needs low stiffness to move through paths in the human body without damaging tissues and high stiffness to keep its shape. This paper presents a variable stiffness manipulator for the endoscopic robot in NOTES. The manipulator has a backbone tube that uses a thermoplastic material, polyethylene terephthalate glycol (PETG), with a temperature effect to change the stiffness. The backbone of the robot is designed with a heating coil, cooling tube, and thermal sensor to adjust the temperature. Analysis and experiments were conducted to evaluate and find the backbone structure with a large range of stiffness modulations, a short heating time, and a short cooling time. This paper also presents a temperature control system that controls the temperature to maintain the stiffness of the robot in real-time. The stiffness characterization, heating time, and cooling time of the robot and the response of the temperature controller, are tested experimentally. The results confirm that the endoscopic robot can be changed and maintained at some stiffness values.
      PubDate: 2022-04-21
       
  • Development of Plantar Pressure Distribution Measurement Shoe Insole with
           Built-in Printed Curved Sensor Structure

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      Abstract: Abstract Foot plantar pressure measurement is one of the most promising approaches for diagnosing foot problems at an early stage for injury prevention and general wellbeing. Information can be derived from the pressure created between the human foot and the support surface in contact with it. This data can be used in gait and posture monitoring for research applications in medical fields, sports, and footwear design. Therefore, it is important to develop an accurate and reliable foot plantar pressure measurement system. This paper presents the development of a plantar pressure measurement insole with embedded printed flexible piezoresistive sensors. The sensing elements of the insole were made from the dispensing of a carbon-based composite with curvilinear shapes. The insole was proved to be suitable for measuring the high-pressure distribution of the different areas of a subject’s foot. Tests to compare the effect of the length of the printed sensors on their performance were carried out. Based on the found results, customizable flexible insoles can be fabricated following the pressure of different regions under the foot.
      PubDate: 2022-04-21
       
  • A Numerical Approach for Predicting the Springback of Intersecting
           High-Stiffened Integral Panel in Spherical Die Forming

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      Abstract: Abstract Taking advantage of the high specific strength, structural efficiency, and rigidity of spherical multi-intersecting high-stiffened integral panels, they have been used on a manned space station as the main load-bearing structure. Due to their large size and complex structure, a new incremental die forming approach was proposed, where the panel is pressed by a relatively small die at devised positions multiple times in proper order. However, the springback behavior of the panel after each depression is extremely complicated due to the interactions between multi-intersecting ribs. In this paper, a numerical approach of springback prediction for a typical intersecting stiffened panel in spherical die forming was proposed and the corresponding algorithm was developed. The approach quantifies the influence between multi-intersecting ribs by a novel definition of a bending neutral layer on the panel: the 3-D springback of whole panel is equivalent to the 2-D springback of the ribs. The strain component led by skin deformation and its elastic release are considered. A plasticity model with a nonlinear strain hardening of material was adopted. The approach was employed to predict the springback of panels with different forming radii, different rib sizes, and local large-rigidity structures. A rapid springback compensation based on the approach was achieved. The calculated results are in strong agreement with the results of FEM simulations based on ABAQUS software and experiments, accurately predicting profiles error within 2 mm.
      PubDate: 2022-04-21
       
  • Kerosene Supply Effect on Performance of Aluminum Nitride Micro-Electrical
           Discharge Machining

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      Abstract: Abstract As interest in aluminum nitride (AlN), a high-performance ceramic, has been rapidly increasing, many researchers studied the possibilities of machining it. Since AlN is classified as a difficult-to-cut material, the electrical discharge machining (EDM) process using an assisting electrode is emerging as an effective machining method. Kerosene, as a dielectric fluid, plays an important role in forming a successive conductive carbon layer on the surface of the workpiece to induce and maintain discharge. Most previous methods used tubular electrodes to stably feed the dielectric fluids through their center hole. However, in the case of micro-EDM, the extremely small electrode diameter makes it difficult to fabricate a through-hole in the electrode, and a very narrow gap prevents the flow of dielectric fluid. In order to overcome dielectric fluid flow problems in micro-EDM, in this study, two kinds of flow-promoting methods are introduced: one is to use a D-shaped solid electrode to obtain a wider asymmetric flow channel, and the other is to use an O-shaped solid electrode with graphite-powder-mixed kerosene (GPMK) under a relatively wider discharge gap. Flow simulation results show that both methods promote kerosene flow, and the experimental results show similar results as well. When using the D-shaped section, the material removal rate increased, but increased tool wear was observed. In the case of GPMK, the metal removal rate increased 64%, and relative wear ratio decreased 73% compared to conventional methods. Through voltage scheduling, the problem of precision degradation that occurs during deep-hole drilling with the O-shaped solid electrode GPMK configuration was solved without sacrificing machinability.
      PubDate: 2022-04-19
       
  • A Study on Tool Breakage Detection During Milling Process Using
           LSTM-Autoencoder and Gaussian Mixture Model

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      Abstract: Abstract In the milling process, a rotating cutting tool is used to cut the raw material into the desired shape. Since tool breakage adversely affects productivity, real-time tool breakage detection is required. In this study, a tool breakage monitoring system using AE signals and a deep learning model was investigated. First, LSTM-Autoencoder was constructed and trained using the AE signal, cutting speed, spindle speed, and depth of cut as input data. In order to distinguish between tool normality and anomalies, the largest value among the normal cutting data set was determined as the threshold to determine if the tool was broken. As the result of the experiment, we obtained the accuracy of 82.1% during normal cutting, but the accuracy was significantly reduced to 63.1% and 63.6% at the time of entry/exit. This is because the AE value that occurs during normal entry/exit is so large that it is mistaken for breakage. To overcome this problem, a combined model that uses both LSTM-Autoencoder and Gaussian Mixture Model was developed. First LSTM-Autoencoder was used to determine the breakage, and then Gaussian Mixture Model was used to determine the authenticity of the breakage. As a result of the experiment using the developed model, 52 out of 57 cuttings including entry/exit cutting were detected as failures, showing a high reliability of 91.2%, proving the superiority of the combined model.
      PubDate: 2022-04-12
       
  • Contact Load and Stiffness of Four-Point Contact Ball Bearings Under
           Loading

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      Abstract: Abstract Four-point contact ball bearings (X-ACBBs) are highly effective in applications requiring support for shafts that feature a high ratio of diameter to unsupported axial length and axial loading in two directions. In an effort to predict and understand problems that have been reported in X-ACCB usage, new modeling and analysis of the contact load and stiffness of X-ACBBs has been presented. The new model features a quasi-static model for X-ACBBs subjected to five degrees-of-freedom loading and displacement. The model was validated against numerical ball contact loads available in the literature. A numerical investigation was then performed to study the effects on ball contact loads and stiffness of rotational speed, external loads, and various geometric parameters of bearings such as arching dimension and unloaded contact angle. Under pure axial load, increasing the rotational speed causes an abrupt change in X-ACBB stiffness when the ball contact changes from two-point to three-point contact. Gyroscopic moment reduces the speed at which transition from two-point to three-point contact occurs. The dependence of X-ACBB stiffness on arching dimension and unloaded contact angle reveals that those parameters are critical for the design of X-ACBBs.
      PubDate: 2022-04-11
       
  • Research on Control Technology of Variable Curvature Bending Springback
           Based on Iterative Compensation Method

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      Abstract: Abstract The springback control method is usually based on surface compensation to make the shape of the springback consistent with the target. At present, it is mainly realized by theoretical calculation or numerical simulation, but the difference between material model and theoretical model leads to unstable compensation accuracy. In this paper, a compensation mechanism which based on the iterative principle of implicit equation is proposed from the point of view of mathematical analysis. The final shape of the part converges to the target shape by means of finite compensation with the iterative method. In this paper, the iterative compensation mechanism is applied to the free bending and stretch-bending processes under plane stress state, and the uniform curvature and variable curvature are compensated iteratively. The next iteration compensation profile is predicted according to the convergence of the iterative principle. Experimental results show that the iterative compensation method can predict the next compensation value, and the error is less than the target value after 2–3 iterations. The error convergence of the method studied in this project is directional and the convergence speed is fast. The compensation value can be quantitatively predicted, which has theoretical significance and application value for engineering design, mold repair and numerical simulation.
      PubDate: 2022-03-22
       
  • Research on Machining Deformation of 7050 Aluminum Alloy Aircraft Rib
           Forging

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      Abstract: Abstract T-type rib strip was the key connective component between the fuselage and wing of the aircraft and the main processes for preparation of T-type rib strip consisted of forging forming, solution quenching, cold pressing and machining. The variation of residual stress and its effect on the deformation during the final machining process was quite complex. In this study, the numerical models of solution quenching, cold pressing and machining of T-type rib strip was established. The variation of residual stress on the deformation of T-type rib strip was studied. The results show that the maximum quenching stress of the T-type rib was about − 200 MPa at the surface and 150 MPa in the core. A reduction of 60% of the average residual stress can be achieved during the cold pressing process with a reduction rate of 3% and a friction coefficient of 0.3. Compared with direct machining after quenching, the deformation of machining after solution quenching and cold pressing was greatly reduced and the reduction rate reached 65.04%.
      PubDate: 2022-03-21
       
  • The Focused Electrode Ring for Electrohydrodynamic Jet and Printing on
           Insulated Substrate

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      Abstract: Abstract Drop-on-demand electrohydrodynamic jet (DoD E-Jet) printing is considered a well-known type of fabrication method contemporary since it can be used to print high-resolution microstructures (< 1 μm) on various insulating substrates. This paper presents a numerical study of DoD E-Jet printing using a novel combination of needle and focused electrode ring to print stable and consistent microdroplets on a Polyethylene terephthalate substrate. Primarily, a phase field method was used to generate a stable cone-jet morphology that can allow the production of high-resolution micron/nano structures on PET substrates. The numerical simulation of cone-jet morphology was performed by COMSOL multiphysics software. Further, the impact of key parameters such as flow rate and dc positive pulse voltage was studied on cone-jet morphology through numerical simulation. Subsequently, optimized operating parameters i.e., f = 5.3 × 10–15 m3 s−1, Vn = 1.9 kV and Vr = 0.7 kV were achieved by performing a series of numerical experiments. Then, optimized parameters by simulation were directly used to print arrays of stable droplets on PET substrate using the focused electrode ring in different locations by regulating distance 0.2 mm to 1.3 mm between needles to focused electrode ring. The minimum size of stable microdrop was measured 3 μm on PET substrate (thickness = 0.2 mm) using a 50 μm size quartz capillary maintaining a distance of 0.2 mm between combined needle and focused electrode ring. The experimental results proved that the simulation model is useful for printing different microstructures on insulating substrates and creating a promising production path for micro-electro mechanical system and nano-electro mechanical system (MEMS and NEMS).
      PubDate: 2022-03-21
       
 
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