Topology Optimization for the Light Rail Vehicle Body Based on Sub-Structure Technology

2013 ◽  
Vol 367 ◽  
pp. 145-150
Author(s):  
Jia Lian Cao ◽  
Jun Yong Li ◽  
Chao Yan Wan
Keyword(s):  
Topology Optimization ◽  
Large Scale ◽  
Volume Fraction ◽  
Element Model ◽  
Optimization Method ◽  
Practical Experience ◽  
Vehicle Body ◽  
Light Rail ◽  
Rail Vehicle ◽  
Technical Requirements

To complete the optimization of large-scale structure such as vehicle body efficiently, a new topology optimization method which combines with sub-structural analysis technology is proposed. With HyperWorks/Optistruct for a platform: first, the finite element model of the light rail vehicle body including sub-structure and non sub-structure is created; second, analyze the most dangerous condition using static reduction method which based on sub-structure technology, output the reduction matrix, generate the sub-structure; and then optimization model is defined including that design variables is the element density, objective function is the minimum volume fraction and constraint is the definition of stress, then enter the reduction matrix, and choose the non sub-structure area for topology optimization; Finally, based on the results, redesign the structure and get the improved one according to the technical requirements and practical experience.

Large-scale three-dimensional anisotropic topology optimization of variable-axial lightweight composite structures

2021 ◽  
pp. 1-15
Author(s):  
Yuqing Zhou ◽  
Tsuyoshi Nomura ◽  
Enpei Zhao ◽  
Kazuhiro Saitou
Keyword(s):  
Topology Optimization ◽  
Composite Structures ◽  
Large Scale ◽  
Volume Fraction ◽  
Three Dimensional ◽  
Optimization Method ◽  
Optimized Design ◽  
Adaptive Meshing ◽  
Design Synthesis ◽  
Fiber Placement

Abstract Variable-axial fiber-reinforced composites allow for local customization of fiber orientation and thicknesses. Despite their significant potential for performance improvement over the conventional multiaxial composites and metals, they pose challenges in design optimization due to the vastly increased design freedom in material orientations. This paper presents an anisotropic topology optimization method for designing large-scale, 3D variable-axial lightweight composite structures subject to multiple load cases. The computational challenges associated with large-scale 3D anisotropic topology optimization with extremely low volume fraction are addressed by a tensor-based representation of 3D orientation that would avoid the 2π periodicity of angular representations such as Euler angles, and an adaptive meshing scheme, which, in conjunction with PDE regularization of the density variables, refines the mesh where structural members appear and coarsens where there is void. The proposed method is applied to designing a heavy-duty drone frame subject to complex multi-loading conditions. Finally, the manufacturability gaps between the optimized design and the fabrication-ready design for Tailored Fiber Placement (TFP) is discussed, which motivates future work toward a fully-automated design synthesis.

Structural topology optimization of bridge girders in cable supported bridges

2018 ◽  
Author(s):  
Mads Baandrup ◽  
Ole Sigmund ◽  
Niels Aage
Keyword(s):  
Topology Optimization ◽  
Large Scale ◽  
Design Method ◽  
Optimization Method ◽  
Bridge Girders ◽  
Structural Topology ◽  
Box Girders ◽  
Box Girder ◽  
Fine Mesh ◽  
Further Development

<p>This work applies a ultra large scale topology optimization method to study the optimal structure of bridge girders in cable supported bridges.</p><p>The current classic orthotropic box girder designs are limited in further development and optimiza­ tion, and suffer from substantial fatigue issues. A great disadvantage of the orthotropic girder is the loads being carried one direction at a time, thus creating stress hot spots and fatigue problems. Hence, a new design concept has the potential to solve many of the limitations in the current state­ of-the-art.</p><p>We present a design method based on ultra large scale topology optimization. The highly detailed structures and fine mesh-discretization permitted by ultra large scale topology optimization reveal new design features and previously unseen eff ects. The results demonstrate the potential of gener­ ating completely different design solutions for bridge girders in cable supported bridges, which dif­ fer significantly from the classic orthotropic box girders.</p><p>The overall goal of the presented work is to identify new and innovative, but at the same time con­ structible and economically reasonable, solutions tobe implemented into the design of future cable supported bridges.</p>

Large-Scale Three-Dimensional Anisotropic Topology Optimization of Variable-Axial Composite Structures

2020 ◽  
Author(s):  
Yuqing Zhou ◽  
Tsuyoshi Nomura ◽  
Enpei Zhao ◽  
Wei Zhang ◽  
Kazuhiro Saitou
Keyword(s):  
Topology Optimization ◽  
Composite Structures ◽  
Large Scale ◽  
Volume Fraction ◽  
Three Dimensional ◽  
Optimized Design ◽  
Adaptive Meshing ◽  
Design Synthesis ◽  
Fiber Placement ◽  
Future Work

Abstract Variable-axial fiber-reinforced composites allow for local customization of fiber orientation and thicknesses. Despite their significant potential for performance improvement over the conventional multiaxial composites and metals, they pose challenges in design optimization due to the vastly increased design freedom in material orientations. This paper presents an anisotropic topology optimization (TO) method for designing large-scale, 3D variable-axial composite structures. The computational challenge for large-scale 3D TO with extremely low volume fraction is addressed by a tensor-based representation of 3D orientation that would avoid the 2π periodicity of angular representation such as Eular angles, and an adaptive meshing scheme, which, in conjunction with PDE regularization of the density variables, refines the mesh where structural members appear and coarsens where there is void. The proposed method is applied to designing a heavy-duty drone frame subject to complex multi-loading conditions. Finally, the manufacturability gaps between the optimized design and the fabrication-ready design for Tailored Fiber Placement (TFP) is discussed, which motivates future work toward fully-automated design synthesis.

scholarly journals A topology optimization method of robot lightweight design based on the finite element model of assembly and its applications

2020 ◽  
Vol 103 (3) ◽  
pp. 003685042093648
Author(s):  
Liansen Sha ◽  
Andi Lin ◽  
Xinqiao Zhao ◽  
Shaolong Kuang
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Topology Optimization ◽  
Lightweight Design ◽  
Element Model ◽  
Optimization Method ◽  
Maximum Displacement ◽  
Element Analysis ◽  
Upper Limb Exoskeleton ◽  
Topology Optimization Method

Topology optimization is a widely used lightweight design method for structural design of the collaborative robot. In this article, a topology optimization method for the robot lightweight design is proposed based on finite element analysis of the assembly so as to get the minimized weight and to avoid the stress analysis distortion phenomenon that compared the conventional topology optimization method by adding equivalent confining forces at the analyzed part’s boundary. For this method, the stress and deformation of the robot’s parts are calculated based on the finite element analysis of the assembly model. Then, the structure of the parts is redesigned with the goal of minimized mass and the constraint of maximum displacement of the robot’s end by topology optimization. The proposed method has the advantages of a better lightweight effect compared with the conventional one, which is demonstrated by a simple two-linkage robot lightweight design. Finally, the method is applied on a 5 degree of freedom upper-limb exoskeleton robot for lightweight design. Results show that there is a 10.4% reduction of the mass compared with the conventional method.

Research on Back Analysis of Parameters for Excavation of the Underground Cavern Group of a Large-Scale Hydro-Power Station by Using Orthogonal Optimization

2012 ◽  
Vol 170-173 ◽  
pp. 3356-3360
Author(s):  
Wen Dong Yang ◽  
Xi Chao Gao ◽  
Yan Mei Zhang ◽  
Jia Yang ◽  
Gang Wang ◽  
...  
Keyword(s):  
Rock Mass ◽  
Large Scale ◽  
Back Analysis ◽  
Element Model ◽  
Optimization Method ◽  
Orthogonal Experimental Design ◽  
Grey System ◽  
Power Station ◽  
Hydro Power ◽  
Underground Cavern

Engineering rock mass is a highly complex grey system, it is impossible to get all the parameters of rock mass by theoretical methods or field measurement approach. Underground engineering feedback analysis method is a reliable way to improve the design, optimization and construction. Based on the field data of underground cavern of a large-scale hydro-power station, the three-dimensional finite element model is established, and orthogonal experimental design and multi-objective optimization method are used for the rapid back analysis. This method could be used for obtaining the rock parameters by inversion calculating in the underground cavern construction of a large-scale hydro-power station. Meanwhile, the inversion parameters could also be applied in the excavation simulation for the next phase and the rock deformation and stability is predicted afterwards. The design and construction sectors are supposed to get its feedback in time, which effectively guarantees the stability of the surrounding rocks.

The effect of spotwelds and structural adhesives on static and dynamic characteristics of vehicle body design

2021 ◽  
pp. 095440702110044
Author(s):  
Gozde Tuncer ◽  
Deniz Mansouri ◽  
Polat Şendur
Keyword(s):  
Topology Optimization ◽  
Element Model ◽  
Vehicle Body ◽  
Functional Requirements ◽  
Performance Indices ◽  
Potential Cost ◽  
Vehicle Performance ◽  
Structural Adhesives ◽  
Body Design ◽  
Structural Adhesive

Spotwelding and structural adhesive applications are two important processes in the automotive industry as they are closely associated with the functional requirements, weight, and cost of the vehicle. Even though there is a vast body of literature on their mathematical models, the effect of these processes on key vehicle performance indices and optimization is rather limited. Besides, the weight benefit of these processes in terms of functional requirements has not been investigated. There are multiple objectives of the paper to fill this gap: (i) to quantify the effect of structural adhesives on the key performance indices (KPIs) of a vehicle body, (ii) to rank the components based on their gauge sensitivities for body KPIs using topometry optimization, (iii) to assess the weight impact of the structural adhesive applications using the gauge sensitivity results, (iv) to determine the optimum layout of the structural adhesive applications using topology optimization, (v) to present a methodology for automotive original equipment manufacturers (OEMs) to determine the “critical welds” on the vehicle body and reduce the number of spotwelds as a potential cost reduction action. For this purpose, a validated finite element model of 2010 Toyota Yaris has been used. Optimization of the structural adhesives and spotwelds was carried-out using SIMP (Solid Isotropic Material with Penalization) based topology optimization. The thickness of each panel is ranked using topometry optimization results. Automotive OEMs can use the proposed methodology to optimize the structural adhesives or spotwelding processes in their product development cycle.

scholarly journals Simulation Analysis of a Multiple-Vehicle, High-Speed Train Collision Using a Simplified Model

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Suchao Xie ◽  
Weilin Yang ◽  
Ping Xu
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
High Speed ◽  
Large Scale ◽  
Computing Time ◽  
Element Model ◽  
Vehicle Body ◽  
Railway Vehicle ◽  
Storage Space ◽  
High Speed Train

To solve the problems associated with multiple-vehicle simulations of railway vehicles including large scale modelling, long computing time, low analysis efficiency, need for high performance computing, and large storage space, the middle part of the train where no plastic deformation occurs in the vehicle body was simplified using mass and beam elements. Comparative analysis of the collisions between a single railway vehicle (including head and intermediate vehicles before, and after, simplification) and a rigid wall showed that variations in impact kinetic energy, internal energy, and impact force (after simplification) are consistent with those of the unsimplified model. Meanwhile, the finite element model of a whole high-speed train was assembled based on the simplified single-vehicle model. The numbers of nodes and elements in the simplified finite element model of the whole train were 63.4% and 61.6%, respectively, compared to those of the unsimplified model. The simplified whole train model using the above method was more accurate than the multibody model. In comparison to the full-size finite element model, it is more specific, had more rapid computational speed, and saved a large amount of computational power and storage space. Finally, the velocity and acceleration data for every car were discussed through the analysis of the collision between two simplified trains at various speeds.

Fully Coupled Three-Scale Finite Element Model for the Mechanical Response of a New Bio-Inspired Composite

2011 ◽  
Author(s):  
Erick I. Saavedra Flores ◽  
Senthil Murugan ◽  
Michael I. Friswell ◽  
Eduardo A. de Souza Neto
Keyword(s):  
Finite Element ◽  
Magnesium Alloy ◽  
Finite Element Model ◽  
Large Scale ◽  
Mechanical Response ◽  
Volume Fraction ◽  
Element Model ◽  
Crystalline Cellulose ◽  
Gauss Point ◽  
Fully Coupled

This paper proposes a fully coupled three-scale finite element model for the mechanical description of an alumina/magnesium alloy/epoxy composite inspired in the mechanics and architecture of wood cellulose fibres. The constitutive response of the composite (the large scale continuum) is described by means of a representative volume element (RVE, corresponding to the intermediate scale) in which the fibre is represented as a periodic alternation of alumina and magnesium alloy fractions. Furthermore, at a lower scale the overall constitutive behavior of the alumina/magnesium alloy fibre is modelled as a single material defined by a large number of RVEs (the smallest material scale) at the Gauss point (intermediate) level. Numerical material tests show that the choice of the volume fraction of alumina based on those volume fractions of crystalline cellulose found in wood cells results in a maximisation of toughness in the present bio-inspired composite.

Frequency-based dynamic topology optimization methodology for improved door closing sound quality

2019 ◽  
Vol 234 (7) ◽  
pp. 1311-1322 ◽  
Author(s):  
Gozde Tuncer ◽  
Polat Sendur
Keyword(s):  
Topology Optimization ◽  
Element Model ◽  
Optimization Method ◽  
Sound Quality ◽  
Sum Of Squares ◽  
Design Parameters ◽  
Design Constraint ◽  
Front Door ◽  
Optimization Methodology ◽  
Material Layout

Door closing sound quality of a vehicle has become one of the most important customer-related quality metrics in the recent years. There has been a vast amount of information on the design parameters contributing to this attribute in the literature. Amongst them, damping pad on the door outer panel emerges as one of the most significant factors on the door closing sound quality. In this paper, we apply solid isotropic material with penalization topology optimization method to determine the optimum material layout for within a given volume constraint on a front door of a typical vehicle. The objective function of the topology optimization is chosen as the minimization of residual sum of squares of the accelerance of the door outer panel up to 200 Hz. The optimization problem is subject to design constraint to use a predetermined percentage of the full damping pad. The methodology is demonstrated on the finite element model of front door of a Toyota vehicle. Two optimization case studies using 60% and 45% of the damping pad on the door outer panel are introduced as a result of the application of the proposed topology optimization methodology. In addition, more manufacturable optimization configurations with the same % of the damping pad are suggested as a means for more feasible application by automotive original equipment manufacturers. All the optimization configurations are compared to each other on (i) accelerance spectrum up to 200 Hz, (ii) residual sum of squares of the accelerance, and (iii) weight of the damping pad. The results show that it is possible to improve the aforementioned metrics significantly by the application of topology optimization.

scholarly journals Topology optimization of transmission gearbox under multiple working loads

2018 ◽  
Vol 10 (11) ◽  
pp. 168781401881345 ◽  
Author(s):  
Mingxuan Liang ◽  
Jianhong Hu ◽  
Shuqing Li ◽  
Zhigao Chen
Keyword(s):  
Finite Element ◽  
Topology Optimization ◽  
Finite Element Model ◽  
Lightweight Design ◽  
Dynamic Performance ◽  
Reference Value ◽  
Element Model ◽  
Optimization Method ◽  
Dynamic Excitation ◽  
Topology Optimization Method

This article is concerned with topology optimization of transmission gearbox under multiple working loads by taking dynamic performance as research object. First, the dynamic excitation model and finite element model are established, the vibration responses of the key points on gearbox are obtained by applying dynamic excitation on finite element model based on modal dynamic method, and the simulation responses are compared with testing results to validate finite element model. Finally, the gearbox structure is optimized by utilizing topology optimization method, and the lightweight model of transmission gearbox structure is redesigned. The dynamic performance indexes such as natural frequency are improved obviously, which indicates that the topology optimization method is very effective in optimizing dynamic performance of complex gearbox structure. The research has an important theoretical significance and reference value for lightweight design of transmission gearbox structure.

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