Application of Topological Optimization Techniques to Structural Crashworthiness

1994 ◽  
Author(s):  
Robert R. Mayer ◽  
Noboru Kikuchl ◽  
Richard A. Scott
Keyword(s):  
Energy Absorption ◽  
Optimality Criteria ◽  
Homogenization Method ◽  
Optimization Techniques ◽  
Topological Optimization ◽  
Crash Analysis ◽  
Original Design ◽  
Element Analysis ◽  
Automotive Body ◽  
Design Variables

Abstract The topological optimization of components to maximize crash energy absorption for a given volume is considered. The crash analysis is performed using a DYNA3D finite element analysis. The original solid elements are replaced by ones with holes, the hole size being characterized by a so-called density (measure of the reduced volume). A homogenization method is used to find elastic moduli as a function of this density. Simpler approximations were developed to find plastic moduli and yield stress as functions of density. Optimality criteria were derived from an optimization statement using densities as the design variables. A resizing algorithm was constructed so that the optimality criteria are approximately satisfied. A novel feature is the introduction of an objective function based on strain energies weighted at specified times. Each different choice of weighting factors leads to a different structure, allowing a range of design possibilities to be explored. The method was applied to an automotive body rear rail. The original design and a new design of equal volume with holes were compared for energy absorption.

Simulation and Analysis on Pressure Resistance Experiments of Automotive Body

2012 ◽  
Vol 490-495 ◽  
pp. 1451-1455
Author(s):  
Guang Yao Zhao ◽  
Yi Feng Zhao ◽  
Chuan Yin Tang ◽  
Zhi Yuan Du
Keyword(s):  
Energy Absorption ◽  
The Body ◽  
Original Design ◽  
Element Analysis ◽  
Vehicle Simulation ◽  
Automotive Body ◽  
Safety Regulations ◽  
Vehicle Rollover ◽  
Pressure Resistance ◽  
Body Energy

Aimed at SUV-type vehicle, simulation and analysis of pressure resistance experiments on the body of automobile has been presented in the paper, according to the vehicle safety regulations and standards of FMVSS216. A limited SUV vehicle model is created; simulation is obtained with the help of software LS-DYNA, based on the principle of finite element analysis method. Assessment of pressure resistance and safety of the automobile has been presented, from the aspect of the deformation of body, the energy absorption of the vehicle and components, and the pressure on the body, etc. By rational improving of the original design of body structure, the reasonable distribution of pressure absorbability of the body of the SUV-type automobile is achieved. The effect of the overall energy absorption of the body is fully exerted, and then the safety of the driver and the passenger in a rollover accident is improved. Research methods and conclusions of this paper provide useful ways and references to the research of the safety of vehicle rollover and design of rationality of body energy absorption

Application of Topological Optimization Techniques to Automotive Front Structure Design

2001 ◽  
Author(s):  
Robert R. Mayer
Keyword(s):  
Optimization Technique ◽  
Shell Element ◽  
Optimality Criteria ◽  
Structure Design ◽  
Optimization Techniques ◽  
Design Concept ◽  
Topological Optimization ◽  
Shell Elements ◽  
Front Structure ◽  
Design Variables

Abstract An application of topological optimization techniques to automotive front structure design was considered, for the case of crashworthiness performance. An earlier developed topological optimization technique was used by first deriving an optimality criteria. To develop an optimality criteria, a functional relationship was developed between microstructure design variables, and both strain energy and volume, for shell element structures. Its previous application was the location of holes to lighten a rear longitudinal rail. The present application applies this theory to the actual layout of automotive front structure. The nonlinear code, LS-DYNA, was used for the simulations. An observation of various automotive front structural topologies, sometimes called structural layouts or architectures, reveals that many different design approaches are possible. In order to numerically assess the optimum layout the design space available for front structure design is built up from layers of shell elements, and the method of constructing these models using LS-INGRID is discussed. Some of these elements are deleted at each optimization iteration, resulting in a design concept. The design concept is interpreted as a number of structural load paths, and a unique design was then identified.

Shape Optimal Design of Contact Springs of Electronic Connectors

2002 ◽  
Vol 124 (3) ◽  
pp. 178-183 ◽  
Author(s):  
Yeh-Liang Hsu ◽  
Yuan-Chan Hsu ◽  
Ming-Sho Hsu
Keyword(s):  
Contact Force ◽  
Printed Circuit Boards ◽  
Normal Force ◽  
Optimization Techniques ◽  
Contact Forces ◽  
Design Parameters ◽  
Original Design ◽  
Insertion Force ◽  
Element Analysis ◽  
Normal Contact

An electronic connector provides a separable interface between two subsystems of an electronic system. The contact spring is probably the most critical component in an electronic connector. Mechanically, the contact spring provides the contact normal force, which establishes the contact interface as the connector is mated. However, connector manufacturers have a basic struggle between the need for high normal contact forces and low insertion forces. Designing connectors with large numbers of pins that are used with today’s integrated circuits and printed circuit boards often results in an associated rise in connector insertion force. It is possible to lower the insertion force of a connector by redesigning the geometry of the contact spring, but this also means a decrease in contact normal force. In this paper, structural shape optimization techniques are used to find the optimal shape of the contact springs of an electronic connector. The process of the insertion of a PCB into the contact springs of a connector is modeled by finite element analysis. The maximum insertion force and the contact normal force are calculated. The effects of several design parameters are discussed. The geometry of the contact springs is then parameterized and optimized. The required insertion force is minimized while the normal contact force and the resulting stress are maintained within specified values. In our example, the insertion force of the final contact spring design is reduced to 68.3% of that of the original design, while the contact force and the maximum stress are maintained within specified values.

Topological Optimization on the Board which above Flexible Clamping Stent Fixture

2012 ◽  
Vol 482-484 ◽  
pp. 784-787
Author(s):  
Da Wei Wu ◽  
Jing Li ◽  
Chang Qing Su
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Topology Optimization ◽  
Design Method ◽  
Substantial Reduction ◽  
Topological Optimization ◽  
Original Design ◽  
Optimum Distribution ◽  
Element Analysis ◽  
Better Than

Topology optimization is a design method to seek an optimum distribution of material according to loading, restraint and objective. Topology optimization was carried out for board – finite element analysis is compared with the original design. The study shows that the stress which on the board was reduced to a great extent. The distribution of the stress was better than before .substantial reduction of quality achieves lightweight. It provides an important technical message for improvement design of the flexible clamping stent fixture.

Optimum Design of Structures with Reference to Space Structures

1995 ◽  
Vol 10 (4) ◽  
pp. 205-214 ◽  
Author(s):  
E. Salajegheh
Keyword(s):  
Optimum Design ◽  
Computational Cost ◽  
Optimization Techniques ◽  
Space Structures ◽  
Continuous Variables ◽  
Original Design ◽  
Approximate Design ◽  
Design Variables ◽  
Discrete Design Variables ◽  
Intermediate Variables

This study presents an efficient method for optimum design of large skeletal and continuum structures, such as space structures, when the design variables are continuous or discrete. Both sizing and shape design variables are considered. First the structural responses such as element forces are approximated in terms of some intermediate variables. By substituting these approximate relations into the original design problem, an explicit nonlinear approximate design task with high quality approximation is achieved. This problem with continuous variables, can be solved by means of numerical optimization techniques very efficiently, the results of which are then used for discrete variable optimization. Now, the approximate problem is converted into a sequence of second level approximation problems of separable form and each of which is solved by a dual strategy with discrete design variables. The approach is efficient in terms of the number of required structural analyses, as well as the overall computational cost of optimization. Examples are offered and compared with other methods to demonstrate the features of the proposed method.

Structural Optimization Based on Stochastic Finite Element Analysis and Optimality Criteria Methods

2011 ◽  
Vol 295-297 ◽  
pp. 2526-2530
Author(s):  
Wei Zhao ◽  
Ji Ke Liu ◽  
Zhong Rong Lu
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Structural Optimization ◽  
Optimality Criteria ◽  
Structural Failure ◽  
Stochastic Finite Element ◽  
Element Analysis ◽  
Design Variables ◽  
Optimality Criteria Method ◽  
Stochastic Finite Element Analysis

An approach for structural optimization with uncertainty is proposed in this paper, which is based on stochastic finite element analysis and an optimality criteria method. The sensitivity analysis of the structural failure probability via design variables are performed by difference method according to stochastic finite element analysis. The information of the partial derivatives is incorporated into the optimality criteria method. The optimization of the section of a beam with uncertainty, as a numerical example, is illustrated by the approach. The results demonstrate the efficiency of the approach.

scholarly journals Topological Optimization of Auxetic Coronary Stents Considering Hemodynamics

2021 ◽  
Vol 9 ◽  
Author(s):  
Huipeng Xue ◽  
Suvash C. Saha ◽  
Susann Beier ◽  
Nigel Jepson ◽  
Zhen Luo
Keyword(s):  
Optimization Method ◽  
Homogenization Method ◽  
Coronary Stents ◽  
Topological Optimization ◽  
Stent Restenosis ◽  
Fluid Permeability ◽  
Design Variables ◽  
New Type ◽  
Mechanical Factors ◽  
New Generation

This paper is to design a new type of auxetic metamaterial-inspired structural architectures to innovate coronary stents under hemodynamics via a topological optimization method. The new architectures will low the occurrence of stent thrombosis (ST) and in-stent restenosis (ISR) associated with the mechanical factors and the adverse hemodynamics. A multiscale level-set approach with the numerical homogenization method and computational fluid dynamics is applied to implement auxetic microarchitectures and stenting structure. A homogenized effective modified fluid permeability (MFP) is proposed to efficiently connect design variables with motions of blood flow around the stent, and a Darcy-Stokes system is used to describe the coupling behavior of the stent structure and fluid. The optimization is formulated to include three objectives from different scales: MFP and auxetic property in the microscale and stenting stiffness in the macroscale. The design is numerically validated in the commercial software MATLAB and ANSYS, respectively. The simulation results show that the new design can not only supply desired auxetic behavior to benefit the deliverability and reduce incidence of the mechanical failure but also improve wall shear stress distribution to low the induced adverse hemodynamic changes. Hence, the proposed stenting architectures can help improve safety in stent implantation, to facilitate design of new generation of stents.

A STUDY ON DESIGN AND CRASH ANALYSIS OF AUTOMOTIVE ENERGY ABSORPTION TUBES

2019 ◽  
Vol 14 (4) ◽  
Author(s):  
Maurya Manishkumar H ◽  
Chinmay K Desai
Keyword(s):  
Numerical Simulation ◽  
Finite Element Analysis ◽  
Energy Absorption ◽  
Human Life ◽  
Crash Analysis ◽  
Element Analysis ◽  
Engineering And Technology ◽  
Stress Energy ◽  
Different Shapes ◽  
Circular Design

In engineering and technology safety of human life has always been a top priority. With the increasing usage of vehicles in everyday life, probability of deaths and injuries has also increased, but safety is important too. The main aim of this study is for designing an energy absorption tubes (Crush Can) of different shapes, thickness, at 10 km/hr speed and checking its performance by numerical simulation on the basis of FMVSS by using Finite Element Analysis and evaluate the result by changing design of Crush Can in the form of stress, energy graphs are plotted, by comparison of results, we can suggest that 1mm thickness and circular design absorb optimum stress and more energy than other. The HYPERMESH software is used in meshing and LS-DYNA software is used as a solver

Application of Computational Mechanics to Tire Design—Yesterday, Today, and Tomorrow

2011 ◽  
Vol 39 (4) ◽  
pp. 223-244 ◽  
Author(s):  
Y. Nakajima
Keyword(s):  
Finite Element ◽  
New Technologies ◽  
Computational Mechanics ◽  
Design Procedure ◽  
Side Wall ◽  
Rolling Resistance ◽  
Optimization Techniques ◽  
Stress Strain ◽  
Element Analysis ◽  
Crown Shape

Abstract The tire technology related with the computational mechanics is reviewed from the standpoint of yesterday, today, and tomorrow. Yesterday: A finite element method was developed in the 1950s as a tool of computational mechanics. In the tire manufacturers, finite element analysis (FEA) was started applying to a tire analysis in the beginning of 1970s and this was much earlier than the vehicle industry, electric industry, and others. The main reason was that construction and configurations of a tire were so complicated that analytical approach could not solve many problems related with tire mechanics. Since commercial software was not so popular in 1970s, in-house axisymmetric codes were developed for three kinds of application such as stress/strain, heat conduction, and modal analysis. Since FEA could make the stress/strain visible in a tire, the application area was mainly tire durability. Today: combining FEA with optimization techniques, the tire design procedure is drastically changed in side wall shape, tire crown shape, pitch variation, tire pattern, etc. So the computational mechanics becomes an indispensable tool for tire industry. Furthermore, an insight to improve tire performance is obtained from the optimized solution and the new technologies were created from the insight. Then, FEA is applied to various areas such as hydroplaning and snow traction based on the formulation of fluid–tire interaction. Since the computational mechanics enables us to see what we could not see, new tire patterns were developed by seeing the streamline in tire contact area and shear stress in snow in traction.Tomorrow: The computational mechanics will be applied in multidisciplinary areas and nano-scale areas to create new technologies. The environmental subjects will be more important such as rolling resistance, noise and wear.

Finite Element Modeling for Steel Cord Analysis in Radial Tires

2013 ◽  
Vol 41 (1) ◽  
pp. 60-79 ◽  
Author(s):  
Wei Yintao ◽  
Luo Yiwen ◽  
Miao Yiming ◽  
Chai Delong ◽  
Feng Xijin
Keyword(s):  
Finite Element ◽  
High Efficiency ◽  
Force Measurement ◽  
Three Dimensional ◽  
Local Stress ◽  
Tension Force ◽  
Center Line ◽  
Element Analysis ◽  
Design Variables ◽  
Steel Cord

ABSTRACT: This article focuses on steel cord deformation and force investigation within heavy-duty radial tires. Typical bending deformation and tension force distributions of steel reinforcement within a truck bus radial (TBR) tire have been obtained, and they provide useful input for the local scale modeling of the steel cord. The three-dimensional carpet plots of the cord force distribution within a TBR tire are presented. The carcass-bending curvature is derived from the deformation of the carcass center line. A high-efficiency modeling approach for layered multistrand cord structures has been developed that uses cord design variables such as lay angle, lay length, and radius of the strand center line as input. Several types of steel cord have been modeled using the developed method as an example. The pure tension for two cords and the combined tension bending under various loading conditions relevant to tire deformation have been simulated by a finite element analysis (FEA). Good agreement has been found between experimental and FEA-determined tension force-displacement curves, and the characteristic structural and plastic deformation phases have been revealed by the FE simulation. Furthermore, some interesting local stress and deformation patterns under combined tension and bending are found that have not been previously reported. In addition, an experimental cord force measurement approach is included in this article.

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