for Journals by Title or ISSN for Articles by Keywords help
 Subjects -> ENGINEERING (Total: 2251 journals)     - CHEMICAL ENGINEERING (188 journals)    - CIVIL ENGINEERING (179 journals)    - ELECTRICAL ENGINEERING (98 journals)    - ENGINEERING (1194 journals)    - ENGINEERING MECHANICS AND MATERIALS (387 journals)    - HYDRAULIC ENGINEERING (55 journals)    - INDUSTRIAL ENGINEERING (61 journals)    - MECHANICAL ENGINEERING (89 journals) CIVIL ENGINEERING (179 journals)
 Showing 1 - 0 of 0 Journals sorted alphabetically ACI Structural Journal       (Followers: 14) Acta Polytechnica : Journal of Advanced Engineering Acta Structilia : Journal for the Physical and Development Sciences       (Followers: 1) Advances in Civil Engineering       (Followers: 31) Advances in Structural Engineering       (Followers: 24) Ambiente Construído       (Followers: 1) American Journal of Civil Engineering and Architecture       (Followers: 24) Architectural Engineering       (Followers: 4) Archives of Civil and Mechanical Engineering Archives of Civil Engineering       (Followers: 8) Archives of Hydro-Engineering and Environmental Mechanics       (Followers: 1) ATBU Journal of Environmental Technology       (Followers: 2) Australian Journal of Structural Engineering       (Followers: 6) Baltic Journal of Road and Bridge Engineering       (Followers: 1) BER : Building and Construction : Full Survey       (Followers: 8) BER : Building Contractors' Survey       (Followers: 4) BER : Building Sub-Contractors' Survey       (Followers: 3) BER : Survey of Business Conditions in Building and Construction : An Executive Summary       (Followers: 4) Berkeley Planning Journal       (Followers: 5) Bioinspired Materials       (Followers: 2) Bridge Structures : Assessment, Design and Construction       (Followers: 14) Building and Environment       (Followers: 15) Building Women Built Environment Project and Asset Management       (Followers: 15) Bulletin of Pridniprovsk State Academy of Civil Engineering and Architecture       (Followers: 4) Canadian Journal of Civil Engineering       (Followers: 9) Case Studies in Engineering Failure Analysis       (Followers: 6) Case Studies in Nondestructive Testing and Evaluation       (Followers: 8) Case Studies in Structural Engineering       (Followers: 8) Cement and Concrete Composites       (Followers: 15) Challenge Journal of Structural Mechanics       (Followers: 4) Change Over Time       (Followers: 2) Civil and Environmental Engineering       (Followers: 7) Civil And Environmental Engineering Reports       (Followers: 4) Civil and Environmental Research       (Followers: 16) Civil Engineering = Siviele Ingenieurswese       (Followers: 4) Civil Engineering and Architecture       (Followers: 11) Civil Engineering and Environmental Systems       (Followers: 2) Civil Engineering and Technology       (Followers: 8) Civil Engineering Dimension       (Followers: 7) Cohesion and Structure       (Followers: 2) Composite Structures       (Followers: 224) Computer-aided Civil and Infrastructure Engineering       (Followers: 8) Computers & Structures       (Followers: 29) Concrete Research Letters       (Followers: 3) Construction Economics and Building       (Followers: 1) Construction Engineering       (Followers: 7) Construction Management and Economics       (Followers: 18) Construction Science       (Followers: 3) Constructive Approximation Curved and Layered Structures       (Followers: 1) DFI Journal : The Journal of the Deep Foundations Institute       (Followers: 1) Earthquake Engineering and Structural Dynamics       (Followers: 15) Enfoque UTE       (Followers: 1) Engineering Project Organization Journal       (Followers: 5) Engineering Structures       (Followers: 12) Engineering Structures and Technologies       (Followers: 1) Engineering, Construction and Architectural Management       (Followers: 12) Environmental Geotechnics       (Followers: 3) European Journal of Environmental and Civil Engineering       (Followers: 6) Fatigue & Fracture of Engineering Materials and Structures       (Followers: 14) Frattura ed Integrità Strutturale : Fracture and Structural Integrity Frontiers in Built Environment Frontiers of Structural and Civil Engineering       (Followers: 6) Geomaterials       (Followers: 2) Geosystem Engineering       (Followers: 1) Geotechnik       (Followers: 1) Géotechnique Letters       (Followers: 4) HBRC Journal       (Followers: 1) Hormigón y Acero HVAC&R Research Indoor and Built Environment       (Followers: 2) Infrastructure Asset Management       (Followers: 1) Insight - Non-Destructive Testing and Condition Monitoring       (Followers: 18) International Journal for Service Learning in Engineering International Journal of 3-D Information Modeling       (Followers: 2) International Journal of Advanced Structural Engineering       (Followers: 13) International Journal of Concrete Structures and Materials       (Followers: 9) International Journal of Condition Monitoring       (Followers: 2) International Journal of Construction Engineering and Management       (Followers: 5) International Journal of Geo-Engineering International Journal of Geosynthetics and Ground Engineering       (Followers: 2) International Journal of Masonry Research and Innovation International Journal of Pavement Research and Technology       (Followers: 2) International Journal of Protective Structures       (Followers: 5) International Journal of Steel Structures       (Followers: 2) International Journal of Structural Engineering       (Followers: 10) International Journal of Structural Integrity       (Followers: 2) International Journal of Structural Stability and Dynamics       (Followers: 6) International Journal of Sustainable Built Environment       (Followers: 3) International Journal of Sustainable Construction Engineering and Technology       (Followers: 7) International Journal on Pavement Engineering & Asphalt Technology       (Followers: 5) Journal of Bridge Engineering       (Followers: 15) Journal of Building Engineering Journal of Building Materials and Structures       (Followers: 1) Journal of Building Performance Simulation       (Followers: 6) Journal of Civil Engineering and Construction Technology       (Followers: 9) Journal of Civil Engineering and Management       (Followers: 6) Journal of Civil Engineering and Science       (Followers: 7) Journal of Civil Engineering Research       (Followers: 6) Journal of Civil Society       (Followers: 3) Journal of Civil Structural Health Monitoring       (Followers: 4) Journal of Composites       (Followers: 77) Journal of Composites for Construction       (Followers: 13) Journal of Computing in Civil Engineering       (Followers: 23) Journal of Construction Engineering       (Followers: 5) Journal of Construction Engineering and Management       (Followers: 19) Journal of Construction Engineering, Technology & Management       (Followers: 2) Journal of Constructional Steel Research       (Followers: 8) Journal of Earth Sciences and Geotechnical Engineering       (Followers: 2) Journal of Fluids and Structures       (Followers: 6) Journal of Frontiers in Construction Engineering       (Followers: 3) Journal of Green Building       (Followers: 11) Journal of Highway and Transportation Research and Development (English Edition)       (Followers: 12) Journal of Infrastructure Systems       (Followers: 20) Journal of Legal Affairs and Dispute Resolution in Engineering and Construction       (Followers: 5) Journal of Marine Science and Engineering       (Followers: 1) Journal of Materials in Civil Engineering       (Followers: 10) Journal of Multifunctional Composites       (Followers: 4) Journal of Nondestructive Evaluation       (Followers: 9) Journal of Offshore Structure and Technology Journal of Performance of Constructed Facilities       (Followers: 4) Journal of Pipeline Systems Engineering and Practice       (Followers: 7) Journal of Rehabilitation in Civil Engineering       (Followers: 1) Journal of Solid Waste Technology and Management Journal of Structural Engineering       (Followers: 37) Journal of Structural Fire Engineering       (Followers: 6) Journal of Sustainable Architecture and Civil Engineering       (Followers: 1) Journal of Sustainable Design and Applied Research in Innovative Engineering of the Built Environment       (Followers: 2) Journal of the South African Institution of Civil Engineering       (Followers: 4) Jurnal Teknik Sipil dan Perencanaan KSCE Journal of Civil Engineering       (Followers: 1) Latin American Journal of Solids and Structures       (Followers: 1) Materiales de Construcción Mathematical Modelling in Civil Engineering       (Followers: 3) Nondestructive Testing And Evaluation       (Followers: 15) Obras y Proyectos       (Followers: 1) Open Journal of Civil Engineering       (Followers: 6) Photonics and Nanostructures - Fundamentals and Applications       (Followers: 3) Practice Periodical on Structural Design and Construction       (Followers: 4) Proceedings of the Institution of Civil Engineers - Bridge Engineering       (Followers: 7) Proceedings of the Institution of Civil Engineers - Civil Engineering       (Followers: 11) Proceedings of the Institution of Civil Engineers - Management, Procurement and Law       (Followers: 6) Proceedings of the Institution of Civil Engineers - Municipal Engineer       (Followers: 3) Proceedings of the Institution of Civil Engineers - Structures and Buildings       (Followers: 4) Random Structures and Algorithms       (Followers: 3) Recent Trends In Civil Engineering & Technology       (Followers: 4) Research in Nondestructive Evaluation       (Followers: 5) Revista IBRACON de Estruturas e Materiais       (Followers: 1) Road Materials and Pavement Design       (Followers: 8) Russian Journal of Nondestructive Testing       (Followers: 4) Science and Engineering of Composite Materials       (Followers: 58) Selected Scientific Papers - Journal of Civil Engineering       (Followers: 3) Slovak Journal of Civil Engineering       (Followers: 2) Soils and foundations       (Followers: 2) Steel Construction - Design and Research       (Followers: 2) Structural and Multidisciplinary Optimization       (Followers: 8) Structural Concrete       (Followers: 9) Structural Control and Health Monitoring       (Followers: 6) Structural Engineering International       (Followers: 10) Structural Safety       (Followers: 7) Structural Survey Structure       (Followers: 25) Structure and Infrastructure Engineering: Maintenance, Management, Life-Cycle Design and Performance       (Followers: 11) Structures Study of Civil Engineering and Architecture       (Followers: 7) Superlattices and Microstructures       (Followers: 2) Surface Innovations Technical Report Civil and Architectural Engineering Teknik The IES Journal Part A: Civil & Structural Engineering       (Followers: 5) The Structural Design of Tall and Special Buildings       (Followers: 5) Thin Films and Nanostructures       (Followers: 1) Thin-Walled Structures       (Followers: 3) Transactions of the VŠB - Technical University of Ostrava. Construction Series       (Followers: 1) Transportation Geotechnics       (Followers: 1) Transportation Infrastructure Geotechnology       (Followers: 8) Water Science & Technology       (Followers: 23) Water Science and Technology : Water Supply       (Followers: 21)

 Structural and Multidisciplinary Optimization   [SJR: 1.603]   [H-I: 77]   [8 followers]  Follow         Hybrid journal (It can contain Open Access articles)    ISSN (Print) 1615-1488 - ISSN (Online) 1615-147X    Published by Springer-Verlag  [2336 journals]
• Level set-based topology optimization for the design of a peltier effect
thermoelectric actuator
• Authors: Kozo Furuta; Kazuhiro Izui; Kentaro Yaji; Takayuki Yamada; Shinji Nishiwaki
Abstract: Abstract Thermoelectric actuators are a type of thermal actuator that generates motion through the input of thermal energy by thermoelectric devices. Thermoelectric actuators utilize thermal expansion and contraction effects, achieved by heating and cooling appropriate parts of the mechanism, which enables specified motions to be carried out and can provide quicker response times than those of typical thermal compliant mechanisms that rely on thermal expansion effects alone. However, the need to consider both thermal expansion and contraction effects makes the design process more complex. This paper proposes a topology optimization method, especially appropriate for the conceptual design of thermoelectric actuators, that uses a level set function to represent structural shape profiles so that optimized configurations have clear structural boundaries. Several numerical examples of thermoelectric actuator design problems are presented to confirm the effectiveness and utility of the proposed method.
PubDate: 2016-10-20
DOI: 10.1007/s00158-016-1609-9

• Robust topology optimization for dynamic compliance minimization under
uncertain harmonic excitations with inhomogeneous eigenvalue analysis
• Authors: Xiaopeng Zhang; Zhan Kang; Wenbo Zhang
Abstract: Abstract Variability of load magnitude/direction is a most significant source of uncertainties in practical engineering. This paper investigates robust topology optimization of structures subjected to uncertain dynamic excitations. The unknown-but-bounded dynamic loads/accelerations are described with the non-probabilistic ellipsoid convex model. The aim of the optimization problem is to minimize the absolute dynamic compliance for the worst-case loading condition. For this purpose, a generalized compliance matrix is defined to construct the objective function. To find the optimal structural layout under uncertain dynamic excitations, we first formulate the robust topology optimization problem into a nested double-loop one. Here, the inner-loop aims to seek the worst-case combination of the excitations (which depends on the current design, and is usually to be found by a global optimization algorithm), and the outer-loop optimizes the structural topology under the found worst-case excitation. To tackle the inherent difficulties associated with such an originally nested formulation, we convert the inner-loop into an inhomogeneous eigenvalue problem using the optimality condition. Thus the double-loop problem is reformulated into an equivalent single-loop one. This formulation ensures that the strict-sense worst-case combination of the uncertain excitations for each intermediate design be located without resorting to a time-consuming global search algorithm. The sensitivity analysis of the worst-case objective function value is derived with the adjoint variable method, and then the optimization problem is solved by a gradient-based mathematical programming method. Numerical examples are presented to illustrate the effectiveness and efficiency of the proposed framework.
PubDate: 2016-10-19
DOI: 10.1007/s00158-016-1607-y

• On curvature approximation in 2D and 3D parameter–free shape
optimization
• Authors: Oliver Schmitt; Paul Steinmann
Abstract: Abstract Manufacturing constraints considered in shape optimization often need to be expressed in terms of curvature. Within the scope of a sensitivity–based parameter–free shape optimization approach, curvature constraints have to be formulated in terms of the FE node coordinates in order to derive the required first order gradients with respect to the design node coordinates. In this contribution we introduce approaches to approximate the curvature of a FE model using the coordinates of the FE nodes at the boundary of the geometry, as a smooth representation of the design boundary is not available. Therefore, in the 2D case we present two different smooth curves which represent the design boundary and for which the curvature can be computed analytically. In a third 2D, as well as in our 3D approach, we use geometric information of the discretization such as the distance to neighboring boundary nodes and edge normals to approximate the curvature at the respective boundary node under consideration.
PubDate: 2016-10-18
DOI: 10.1007/s00158-016-1595-y

• Reliability-based design optimization applied to structures submitted to
• Authors: Younès Aoues; Emmanuel Pagnacco; Didier Lemosse; Leila Khalij
Abstract: Abstract The reliability-based design optimization (RBDO) aims to find the most balanced design through a compromise between cost and safety when uncertainties affecting the system are considered. This strategy involves the evaluation of probabilistic constraints performed by the reliability analysis, leading to an expensive computational effort in order to solve the problem. For this reason, it is not trivial to take into account the high cycle fatigue in a RBDO method. This work deals with this problem, considering stationary Gaussian random load processes and the Sines multiaxial fatigue criterion. The efficiency is achieved through spectral tools related to the fatigue analysis. Therefore, the probabilistic constraints of the fatigue life in the RBDO problem are transformed in the frequency domain. The limit state function of the reliability analysis is defined by the mechanical component endurance submitted to random loads. The numerical application demonstrates the interest and the effectiveness of our proposal.
PubDate: 2016-10-17
DOI: 10.1007/s00158-016-1604-1

• Multi-objective and multi-case reliability-based design optimization for
tailor rolled blank (TRB) structures
• Authors: Guangyong Sun; Huile Zhang; Jianguang Fang; Guangyao Li; Qing Li
PubDate: 2016-10-17
DOI: 10.1007/s00158-016-1592-1

• Identifying boundaries of topology optimization results using basic
parametric features
• Authors: Guilian Yi; Nam H. Kim
Abstract: Abstract Topology optimization yields an overall layout of a structure in the form of discrete densities or continuous boundaries. One of important drawbacks, however, is that a serious gap exists between the topology results (e.g., greyscale images with irregular shapes) and parameterized CAD models that are ready for subsequent optimization and manufacturing. Without the corresponding CAD model, topology optimization design is difficult to be interpreted for manufacturing, as well as to be utilized in subsequent applications such as section and shape optimization. It is considered the most significant bottleneck to interpret topology optimization results and to produce a parameterized CAD model that can be used for subsequent optimization. The objective of this paper is to extract geometric features out of topology designs for parameterized CAD models with minimal manual intervention. The active contour method is first used to extract boundary segments from topology geometry. Using the information of roundness and curvature of segments, basic geometric features, such as lines, arcs, circles and fillets, are then identified. An optimization method is used to find parameters of these geometric features by minimizing errors between the boundary of geometric features and corresponding segments. Lastly, using the parameterized CAD model, section optimization is performed for beam-like structures, and surrogate-based shape optimization is employed to determine the final shapes. The entire process is automated with MATLAB and Python scripts in Abaqus, while manual intervention is needed only when defining geometric constraints and design parameters. Three examples are presented to demonstrate effectiveness of the proposed methods.
PubDate: 2016-10-15
DOI: 10.1007/s00158-016-1597-9

• A VF-SLP framework using least squares hybrid scaling for RBDO
• Authors: Xiaoke Li; Haobo Qiu; Zheng Jiang; Liang Gao; Xinyu Shao
Abstract: Abstract Using computationally cheap low-fidelity (LF) model and more accurate but expensive high-fidelity (HF) model, variable fidelity (VF) model has been widely used in engineering design to replace the actual computationally expensive experiments or computer simulations. To further extend the application of VF to reliability-based design optimization (RBDO), a new framework based on sequential linear programming (SLP) is proposed in this paper. Combining the advantages of additive scaling method and multiplicative scaling method, a hybrid scaling method based on least squares (LSHS) is developed. In LSHS method, the VF model is introduced to replace the implicit performance function in RBDO by using the HF function values and gradient values at all evaluated points around the current design. With the failure probability and its gradient calculated by Monte Carlo Simulation (MCS) at current design, SLP is adopted to calculate the next design. A novel method which considers the target reliability index and the influence domain at the current design is also developed to determine the step size in every sub-optimization problem. Two numerical examples and the shape optimization problem of a curved beam are analyzed in order to demonstrate the performance of the proposed methodology. The comparison results show that the proposed method is very accurate and efficient.
PubDate: 2016-10-13
DOI: 10.1007/s00158-016-1588-x

• Design of pipeline opening layout through level set topology optimization
• Authors: Jikai Liu; Yongsheng Ma
Abstract: Abstract Perforated pipeline structure is widely utilized in the oil industry for its special functionality of communicating media with the ambient environment. A typical application is the slotted liner in SAGD (Steam Assisted Gravity Drainage) process, where the pipeline structure is manufactured with open slots to spread hot steam and collect the melted oil. Generally, a dense opening layout is employed to reduce flow resistance. On the other hand, inclusion of the many openings severely reduces the structural strength and stiffness, which causes the pipeline prone to deformation or even failure. Therefore, there exist the two conflicting requirements for design of the pipeline opening layout, and an interesting solution is proposed in this paper. To be specific, the pipeline structure is discretized into shell elements which are categorized into multiple types: without opening, with opening type 1, with opening type 2, etc. These element types are treated as different material phases, and design of the pipeline opening layout is transformed into a multi-material topology optimization problem. Multi-material level set method is employed to solve it, subject to the compliance minimization objective. In addition, a lower bound of opening quantity is applied by properly configuring the material fraction constraint, which ensures the low flow resistance. The effectiveness of the proposed method is proven through a few numerical case studies.
PubDate: 2016-10-12
DOI: 10.1007/s00158-016-1602-3

• Drop test simulation and surrogate-based optimization of a dishwasher
mechanical structure and its packaging module
• Authors: O. Mülkoğlu; M. A. Güler; E. Acar; H. Demirbağ
Abstract: Abstract A drop test simulation of the mechanical structure of a redesigned dishwasher is performed by using a detailed finite element (FE) model. The nonlinear explicit FE code LS-DYNA® is used for the drop impact simulations. The FE model is validated through real tests of two drop scenarios (vertical and inclined to the side). An optimization study is performed in order to determine the optimum design variables for better crash performance. The effects of geometric parameters and material properties on the weights of certain components (ie, dogleg plate and bottom foam) are investigated. A surrogate-based optimization approach is used to find optimum values for the dogleg plate thickness, bottom foam density and increment of the bottom foam height to minimize the weights of both components. Two different surrogate models are used to predict optimization problem constraints that have a crucial role in the crash performance of the dishwasher mechanical structure and packaging module: the polynomial response surface and radial basis functions. The results showed that the dogleg plate mass can be slightly reduced and the bottom foam mass can be significantly reduced in order to obtain the optimum dishwasher configuration and better crashworthiness. The weights of the dogleg plate and bottom foam could be lowered by as much as 5.95 and 24.8 %, respectively. Finally, multi-objective optimization is performed by minimizing a composite objective function that provides a compromise between the weights of both components. The results showed that weight reductions of 2.3 and 21.5 % could be obtained for the dogleg plate and bottom foam, respectively.
PubDate: 2016-10-12
DOI: 10.1007/s00158-016-1585-0

• Special issue dedicated to Founding Editor George Rozvany
• Authors: Ming Zhou; Gregoire Allaire; Gengdong Cheng; Jianbin Du; Matthew Gilbert; Xu Guo; James Guest; Raphael Haftka; Alicia Kim; Thomas Lewinski; Kurt Maute; Julian Norato; Niels Olhoff; Glaucio H Paulino; Tomasz Sokol; Michael Wang; Ren-Jye Yang; Byeng Dong Youn
PubDate: 2016-10-11
DOI: 10.1007/s00158-016-1591-2

• Time-variant global reliability sensitivity analysis of structures with
both input random variables and stochastic processes
• Authors: Pengfei Wei; Yanyan Wang; Chenghu Tang
Abstract: Abstract The ubiquitous uncertainties presented in the input factors (e.g., material properties and loads) commonly lead to occasional failure of mechanical systems, and these input factors are generally characterized as random variables or stochastic processes. For identifying the contributions of the uncertainties presented in the input factors to the time-variant reliability, this work develops a time-variant global reliability sensitivity (GRS) analysis technique based on Sobol’ indices and Karhunen- Loève (KL) expansion. The proposed GRS indices are shown to be effective in identifying the individual, interaction and total effects of both the random variables and stochastic processes on the time-variant reliability, and can be especially useful for reliability-based design. Three numerical methods, including the Monte Carlo simulation (MCS), the first order envelope function (FOEF) and the active learning Kriging Monte Carlo simulation (AK-MCS), are introduced for efficiently estimating the proposed GRS indices. A numerical example, a beam structure and a ten-bar structure under time-variant loads are introduced for demonstrating the significance of the time-variant GRS analysis technique and the effectiveness of the numerical methods.
PubDate: 2016-10-08
DOI: 10.1007/s00158-016-1598-8

• Coupling the cross-entropy with the line sampling method for risk-based
design optimization
• Authors: Ivan Depina; Iason Papaioannou; Daniel Straub; Gudmund Eiksund
Abstract: Abstract An algorithm for risk-based optimization (RO) of engineering systems is proposed, which couples the Cross-entropy (CE) optimization method with the Line Sampling (LS) reliability method. The CE-LS algorithm relies on the CE method to optimize the total cost of a system that is composed of the design and operation cost (e.g., production cost) and the expected failure cost (i.e., failure risk). Guided by the random search of the CE method, the algorithm proceeds iteratively to update a set of random search distributions such that the optimal or near-optimal solution is likely to occur. The LS-based failure probability estimates are required to evaluate the failure risk. Throughout the optimization process, the coupling relies on a local weighted average approximation of the probability of failure to reduce the computational demands associated with RO. As the CE-LS algorithm proceeds to locate a region of design parameters with near-optimal solutions, the local weighted average approximation of the probability of failure is refined. The adaptive refinement procedure is repeatedly applied until convergence criteria with respect to both the optimization and the approximation of the failure probability are satisfied. The performance of the proposed optimization heuristic is examined empirically on several RO problems, including the design of a monopile foundation for offshore wind turbines.
PubDate: 2016-10-07
DOI: 10.1007/s00158-016-1596-x

• Topology design of thermomechanical actuators
• Abstract: Abstract The paper deals with topology design of thermomechanical actuators. The goal of shape optimization is to maximize the output displacement in a given direction on the boundary of the elastic body, which is submitted to a thermal excitation that induces a dilatation/contraction of the thermomechanical device. The optimal structure is identified by an elastic material distribution, while a very compliant (weak) material is used to mimic voids. The mathematical model of an actuator takes the form of a semi-coupled system of partial differential equations. The boundary value problem includes two components, the Navier equation for linear elasticity coupled with the Poisson equation for steady-state heat conduction. The mechanical coupling is the thermal stress induced by the temperature field. Given the integral shape functional, we evaluate its topological derivative with respect to the nucleation of a small circular inclusion with the thermomechanical properties governed by two contrast parameters. The obtained topological derivative is employed to generate a steepest descent direction within the level set numerical procedure of topology optimization in a fixed geometrical domain. Finally, several finite element-based examples for the topology design of thermomechanical actuators are presented.
PubDate: 2016-10-04
DOI: 10.1007/s00158-016-1593-0

• A new approach to optimization of viscoelastic beams: minimization of the
input/output transfer function H ∞ $\boldsymbol {H}_{\infty }$ -norm
• Abstract: A new approach to structural optimization in dynamic regime is presented that is based on the minimization of the $$H_{\infty }$$ norm of the transfer function between the external loads and the structural response. The method is successfully applied to the sizing optimization of viscoelastic beams as shown by extensive numerical investigations that are presented in much detail. The abstract nature of the proposed approach makes it applicable to a wide class of dynamical systems including 2D and 3D systems within general topology optimization frameworks that are object of ongoing analysis.
PubDate: 2016-10-03
DOI: 10.1007/s00158-016-1600-5

• Improving topology optimization intuition through games
• Authors: Morten Nobel-Jørgensen; David Malmgren-Hansen; J. Andreas Bærentzen; Ole Sigmund; Niels Aage
Abstract: Abstract This paper describes the educational game, TopOpt Game, which invites the player to solve various optimization challenges. The main purpose of gamifying topology optimization is to create a supplemental educational tool which can be used to introduce concepts of topology optimization to newcomers as well as to train human intuition of topology optimization. The players are challenged to solve the standard minimum compliance problem in 2D by distributing material in a design domain given a number of loads and supports with a material constraint. A statistical analysis of the gameplay data shows that players achieve higher scores the more they play the game. The game is freely available for the iOS platform at Apple’s App Store and at http://www.topopt.dtu.dk/?q=node/909 for Windows and OSX.
PubDate: 2016-10-01
DOI: 10.1007/s00158-016-1443-0

• Topology design of compliant mechanisms with stress constraints based on
the topological derivative concept
• Authors: Cinthia G. Lopes; Antonio A. Novotny
Abstract: Abstract Compliant mechanisms are mechanical devices composed by one single piece that transforms simple inputs into complex movements. This kind of multi-flexible structure can be manufactured at a very small scale. Therefore, the spectrum of applications of such microtools has become broader in recent years including microsurgery, nanotechnology processing, among others. In this paper, we deal with topology design of compliant mechanisms under von Mises stress constraints. The topology optimization problem is addressed with an efficient approach based on the topological derivative concept and a level-set domain representation method. The resulting topology optimization algorithm is remarkably efficient and of simple computational implementation. Finally, some numerical experiments are presented, showing that the proposed approach naturally avoids the undesirable flexible joints (hinges) by keeping the stress level under control.
PubDate: 2016-10-01
DOI: 10.1007/s00158-016-1436-z

• Obtaining a hyperelastic non-linear orthotropic material model via inverse
bubble inflation analysis
• Authors: Charles F. Jekel; Gerhard Venter; Martin P. Venter
Abstract: Abstract An inverse bubble inflation test is proposed utilizing full displacement field matching to obtain non-linear material models suitable for the Finite Element (FE) method. In this paper a known non-linear orthotropic material model is assumed as the solution for the inverse method to illustrate the process. A bubble inflation FE analysis is performed with the known material model to determine the load and displacement field from the assumed material. Polynomial surfaces are fit to the nodal displacement values of the FE model, such that the entire displacement field is stored as three unique polynomial surfaces. An error formulation was established to quantify the quality of fit between different bubble inflation displacement fields. Gradient based optimization is used to obtain the assumed material model by matching the full displacement field. The inverse bubble inflation test successful produces a non-linear orthotropic model that is analogous to the assumed non-linear orthotropic material, and thus demonstrates that the inverse bubble inflation analysis would be able to characterize other non-linear orthotropic materials.
PubDate: 2016-10-01
DOI: 10.1007/s00158-016-1456-8

• Topology optimization of industrial robots for system-level stiffness
maximization by using part-level metamodels
• Authors: Byung Jun Kim; Dae Kyu Yun; Sang Hun Lee; Gang-Won Jang
Abstract: Abstract This investigation presents a topology optimization method for the design of lightweight serial robots for industrial applications such as welding robots and painting robots. It might be numerically efficient to perform topology optimization of a robot structure by dividing the problem into part-level optimization problems. However, the robot structure whose parts are separately optimized is not necessarily the optimized structure in the system level. For example, a robot whose parts are separately designed to have maximum stiffness-to-mass ratio cannot have the maximum stiffness in the system level. This is because it is impossible to know in the stage of the problem formulation how the total mass should be divided into each part to have maximized system stiffness. To deal with this, a metamodel relating the stiffness and the mass usage is constructed in each part-level optimization problem. The proper division of a mass in the part level is determined by solving the system-level optimization problem which is formulated by using the part-level metamodels. Optimized robot structures obtained by the proposed approach are shown to have performances close to system-level optimized ones in test problems with two- and three-dimensional static and dynamic cases. Based on the proposed idea, topology optimization of a painting robot is performed; a base frame, a lower frame and an upper frame of the robot are optimized to lower the maximum system strain energy during the motion.
PubDate: 2016-10-01
DOI: 10.1007/s00158-016-1446-x

• Accurate analysis and thickness optimization of tailor rolled blanks based
on isogeometric analysis
• Authors: C. S. Ding; X. Y. Cui; G. Y. Li
Abstract: Abstract Combined isogeometric analysis (IGA) and shape optimization, this paper provides a method that can accurately analyze Tailor Rolled Blanks (TRB) and optimize its thickness profile continuously. While existed traditional methods can hardly solve these problems. TRB has a continuous transition between the thick and thin and a better surface quality. We found in IGA, two-dimension NURBS could present TRB geometry model exactly, but Kirchhoff shell element whose control points are allocated different thicknesses could not simulate TRB effectively. So, this paper uses three-dimension NURBS element to exactly present and accurately analyze TRB. It could avoid error caused by inaccurate presentation of geometry model and decrease error caused by solution field (displacement) approximation in numerical computation. Meanwhile, the positions of control points are taken as design variables in process of optimizing thickness profile. It can avoid the appearance of “unrealistic” shape and save lots of time spent in traditional tediously mesh updating as well as having better accuracy. This method makes accurate analysis and continuous thickness optimization of TRB become possible. It pushes the development of TRB engineering and extends the applications of IGA optimization. Several examples including benchmarks and application used the proposed method verified its effectivity, reliability and efficiency.
PubDate: 2016-10-01
DOI: 10.1007/s00158-016-1448-8

• Multidisciplinary design optimization of tunnel boring machine considering

• Authors: Wei Sun; Xiaobang Wang; Lintao Wang; Jie Zhang; Xueguan Song
Abstract: Abstract A Tunnel Boring Machine (TBM) is an extremely large and complex engineering machine that usually works under a complicated geological environment to excavate tunnel underground. Considering the large number of sub-systems that usually belong to different disciplines, it is a challenging task to define, model, and optimize the whole TBM from the perspective of system engineering. Also, due to the complex mechanism and geological environment, the flexibility and efficiency of existing TBM excavation strategies are generally limited. To address these challenges, a multidisciplinary modeling is presented so that corresponding analytical or empirical models of each sub-system are formulated, and a multidisciplinary design optimization (MDO) method is applied to the TBM system optimization. Four excavation strategies are studied and compared, including: (i) two existing excavation strategies, and (ii) two new proposed excavation strategies by making control and/or structure parameters adaptive to geological conditions. Two case studies with these four excavation strategies are presented to illustrate the effectiveness and benefits of designing TBM using MDO methodologies. Wherein, Case I aims to minimize the construction period taking into account the restriction of sub-systems, and Case II simultaneously minimizes construction period, cost, and energy consumption. Since the resulting MDO formulation is straightforward to be solved as a single problem, the All-At-Once (AAO) method is utilized in this paper. The optimization results obtained by modeling the problem as MDO show that the excavation strategy with adaptive control and structure parameters can significantly reduce the total construction time, with lower cost and energy consumption.
PubDate: 2016-10-01
DOI: 10.1007/s00158-016-1455-9

JournalTOCs
School of Mathematical and Computer Sciences
Heriot-Watt University
Edinburgh, EH14 4AS, UK
Email: journaltocs@hw.ac.uk
Tel: +00 44 (0)131 4513762
Fax: +00 44 (0)131 4513327

Home (Search)
Subjects A-Z
Publishers A-Z
Customise
APIs