The problem of topology optimization as a very general approach to obtain optimum structures is often addressed as a material distribution problem. Structural topology optimization using genetic algorithms. The goal of crashworthiness design is to maximize the energy absorption during a crash event. Oct 21, 2006 topology optimization has developed rapidly, primarily with application on linear elastic structures subjected to static loadcases.
Topology optimization crashworthiness heuristic approach graph theory optimization in nonlinear dynamics 3. Hierarchical topology and shape optimization of crashloaded. Crashworthiness design using topology optimization curatend. Several attempts have been made to use optimization methods in crashworthiness design problems. A new topology optimization approach for crashworthiness of passenger vehicles based on physically defined equivalent static loads, proceedings of the icrash conference, milano, italy, 2012. Optimization for structural crashworthiness and energy absorption has become an important topic of research attributable to its proven benefits to public safety and social economy. Among various structural optimization techniques, topology optimization techniques are usually preferred to address the issue of crashworthiness. A hybrid approach to structural topology optimization of.
Structural topology optimization for blast mitigation using hybrid cellular automata page 2 of 9. Optimization of structural crashworthiness is a challenging task due to the highly. Forsberg 5 has studied accuracy aspects of rsm using linear polynomials and kriging. There are three main types of structural optimization.
Introduction in many areas of the structural design methods for topology optimization are applied very successfully but up to now the topology synthesis of crashloaded structures is difficult. Lightweight hybrid electrical vehicle structural topology optimisation investigation focusing on crashworthiness jesper christensena,d, christophe bastiena,b, mike blundella,c, andrew gittense,f, and oliver tomline,g afaculty of engineering and computing,coventry university, uk. Benchmark of topology optimization methods for crashworthiness design c. A new method for crashworthiness optimization of vehicle structures is presented, where an early design. This domain is discretized into a large number of elements in which the optimization algorithm removes, adds, or maintains the amount of material. When an explicit finite element method is used to solve contactimpact problems. Result is embedded in an overall loop topology shape size optimization. Pdf crashworthiness design using topology optimization. Design optimization, safety, vehicle, topology, crashworthiness. Nested topology optimization methodology for designing twowheel chassis stefanos e. There are two methods to solve topology optimization problems.
Topology optimization has developed rapidly, primarily with. The results are compared with the dynamic response optimization method using esls eslso. Crashworthiness design using topology optimization 21 may 2009 journal of mechanical design, vol. This work introduces a clusterbased structural optimization cbso method for the design of categorical multimaterial structures subjected to crushing, dynamic loading. Keulen, levelset methods for structural topology optimiza. Pdf topology optimization has developed rapidly, primarily with application on linear elastic structures subjected to static loadcases. Mayer research and development center, general motors corporation bldg. A topology optimization algorithm of a shell structure for crashworthiness was presentdted.
In addition, strain constraints have to be provided in order to prevent structural failure. Topology optimization to is a mathematical method that optimizes material layout within a given design space, for a given set of loads, boundary conditions and constraints with the goal of maximizing the performance of the system. Today, rsm is the preferred optimization method in vehicle crashworthiness design. An efficient topology optimization strategy for structural. The editors hope that this special issue will give readers new perspectives and suggest especially fruitful directions. In crashworthiness design some drawback exists on the application of standard optimization methods, and particularly for topology optimization of crashworthiness designs the. Structural topology optimization for crashworthiness. Evolutionary crashworthiness topology optimization of thin. Topology optimization is a tool for nding a domain in which material is placed that optimizes a certain objective function subject to constraints. Request pdf structural topology optimization for crashworthiness this paper presents a method to obtain optimum topologies of structures subject to impact.
Although topology optimization is well established in most engineering fields, it is still in its infancy concerning highly nonlinear structural applications like vehicular crashworthiness. At the end of the topology optimization process, some finite elements in the design space will be kept and others are deleted. The structural material will be distributed to those remaining elements. Design optimization of vehicle structures for crashworthiness. On design optimization for structural crashworthiness and its.
The existing study in structural topology optimization mostly focuses on static analysis of the linear elastic structure. Structural optimization has turned out to be helpful in solving automative design problems in order to. The results show that, the proposed method can efficiently solve structural topology optimization problems for crashworthiness. To is different from shape optimization and sizing optimization in the sense that the design can attain any. Click the props entity selector box and select the property design. Lightweight hybrid electrical vehicle structural topology optimisation investigation focusing on crashworthiness. Development and evaluation of level set methods for. A numerical example is used to verify the reliability of the proposed method. Response from the automotive industry includes vehicles whose primary propulsion systems are not based upon fossil fuels. Design for crashworthiness of categorical multimaterial. Crashworthiness design using topology optimization. As focus on global climate rises, so does demand for ever more environmentally friendly technologies. Although topology optimization is well established for linear cases, there are only a few methods available for crashworthiness. Zeng, topology optimization for crashworthiness of thinwalled structures under axial impact using hybrid cellular automata, structural and multidisciplinary optimization, 543.
Pedersen, topology optimization design of crushed 2dframes for desired energy absorption history, structural and multidisciplinary optimization. Define a topology design variable for the design region 1. The optimal topol ogy in the design space is thus created. Topology optimization has developed rapidly, primarily with application on linear elastic structures subjected to static loadcases. Topology optimization for crash eslm may11 duddeck 32 equivalent static load method eslm and standard topology optimization linear fem. The primary goal of this dissertation is the development of a topology optimization approach for application to vehicle crashworthiness design that utilizes high fidelity crash simulations. Crashworthiness, topology optimization, thinwalled structures, hybrid cellular automata. It may be good to distinguish three main categories of crashworthiness optimization research. Cost and mass optimization for crashworthiness design of shellbased structure using hybrid cellular automata. Crashworthiness design using topology optimization journal. While such a manual tuning of the design via crush mode matching is. Lightweight hybrid electrical vehicle structural topology. Thickness based topology optimization for crashworthiness. Technical overview of the equivalent static loads method for nonlinear static response structural optimization, structural and multidisciplinary optimization 43.
Topology optimization based on graph theory of crash loaded. The difficulty of gradient calculation in crashworthiness design problem constitutes a major obstacle to apply the existing topology optimization methods such as. Multimaterial structural topology optimization for blast mitigation using hybrid cellular auomata. The optimization method utilized the homogenization technique. Topology optimization for crashworthiness of frame. Topology optimization in crashworthiness design article pdf available in structural and multidisciplinary optimization 331. Topology optimization for crashworthiness has been investigated during the last years, starting from methods based on linear elastic and static simulations 1 or socalled equivalent static loads. First, the design criteria used in crashworthiness and energy. Structural optimization of thin walled tubular structure. Thickness based topology optimization for crashworthiness design using hybrid cellular automata. Request pdf structural topology optimization for crashworthiness this paper presents a method to obtain optimum topologies of structures subject to impact loads that produce geometric and. A new topology optimization approach for crashworthiness. Crash simulations with fe models are computationally too expensive and noisy. Pedersen, crashworthiness design of transient frame structures using topology optimization, computer methods in applied mechanics and engineering, 193, 68, 653, 2004.
Topology design of vehicle structures for crashworthiness. On design optimization for structural crashworthiness and. Topology optimization for crashworthiness of thinwalled. Yang ford motor company abstract linear structural topology optimization has been widely studied and implemented into various engineering. This thesis considers topology optimization for structural mechanics problems, where the underlying pde is derived from linear elasticity. In its basic form, an approximated optimization problem is formulated using analytical or semianalytical methods to perform the sensitivity analysis.
Applications of shape and topology optimization reach from crashworthiness of transport vehicles and tunnel design to biomechanical applications such as bone remodelling. In this paper, a heuristic approach to continuumbased topology optimization is developed for crashworthiness design. To is different from shape optimization and sizing optimization in the sense that the design can attain any shape within the design space, instead. Structural topology optimization of vehicle for crashworthiness is a challenging subject because it involves geometric and material nonlinearity as well as transit dynamic analysis. Structural optimization of thin walled tubular structure for. Topology optimization based on graph theory of crash. Although many gradient based and heuristic methods for topology and topometry based crashworthiness design are available these days, most of them result in stiff structures that are suitable only for a set of vehicle components in which maximizing the energy absorption or minimizing the intrusion is the main concern. Nested topology optimization methodology for designing two. Topology optimization, explicit finite element analysis, contactimpact. One of the approaches recently proposed and based on hybrid cellular automata is modified here such that it can be applied for the first time to thinwalled structures. Topology optimization of structural members for crashworthiness. On design optimization for structural crashworthiness and its state of the art. The hybrid cellular automaton hca is a truly nonlinear explicit topology design method developed for obtaining conceptual designs of crashworthy vehicle components. Before solving an optimization problem, an optimization formulation has to be made and a model for calculation created.
Furthermore, topology optimization in vehicle structure generally provides a concept, not a. Pedersen cbw 2004 crashworthiness design of transient frame structures using topology optimization. The methodology utilizes the cellular automata paradigm to generate threedimensional design concepts. Crashworthiness topology optimization of thinwalled. Topology optimization is an iterative process that determines the best arrangement of material so as to obtain an optimal performance of the concept design. Optimization has been successfully used in many fields of science, for example, see. A magic cube approach for crashworthiness and blast protection designs of structural and material systems by chang qi a dissertation submitted in partial fulfillment of the requirements for the degree of doctor of philosophy mechanical engineering in the university of michigan 2008 doctoral committee. The existing study in structural topology optimization focuses on static analysis of the linear elastic mostly structure. Furthermore, topology optimization in vehicle structure generally provides a concept. Incorporation of nonlinearities to the optimization. Optimization analysis on the crashworthiness of light aircrafts. American institute of aeronautics and astronautics 12700 sunrise valley drive, suite 200 reston, va 201915807 703.
May 21, 2009 in this paper, a heuristic approach to continuumbased topology optimization is developed for crashworthiness design. Apr, 2016 although topology optimization is well established in most engineering fields, it is still in its infancy concerning highly nonlinear structural applications like vehicular crashworthiness. This is due to the high nonlinearity of the problem. Although equivalent static loads esls provides a relatively effective way to solve nonlinear dynamic response topology optimization problems, efficiency is still required to improve. On design optimization for structural crashworthiness 1093. Topology optimization of transient nonlinear structures. Structural topology optimization for crashworthiness request pdf. Optimality conditions of the hybrid cellular automata for. Topology optimization in crashworthiness design springerlink. To protect passengers, large aircraft are equipped with multiple mechanisms to absorb impact energy during a crash. Optimization analysis on the crashworthiness of light.
Design for structural topology optimization is a method of distributing material within a design domain of prescribed dimensions. In this study, topology optimization of a thinwalled square tube subjected to an axial crushing load was carried out to enhance its crashworthiness performance, utilizing the modified bidirectional evolutionary structural optimization beso procedure. Yang ford motor company abstract linear structural topology optimization has been widely studied and implemented into various engineering applications. Topology optimization in crashworthiness design dynalook. Crashworthiness design using topology optimization neal m. Pdf topology optimization in crashworthiness design. A hybrid approach to structural topology optimization of vehicle for. Structural topology optimization is a powerful and wellestablished technique to determine the optimal geometry to design efficient systems. Equivalent loads are defined for different time steps based on energy considerations. Crashworthiness design using topology optimization, phd thesis, university of. The difficulty of crashworthiness analysis is widely recognized, because it involves highly nonlinear and dynamic effects of the vehicle structure. Employment of the density method density on the nodeemployment of the density method density on the node. In the topology panel under the optimization section of the analysis page, under desvar, enter the name design. While such a manual tuning of the design via crush mode.
Hierarchical topology and shape optimization of crash. This paper presents an efficient structural topology optimization strategy for crashworthiness. Under the dropdown selector for type, select psolid. When an explicit finite element method is used to solve contactimpact problems, the sensitivities cannot. Crashworthiness topology optimization of thinwalled square.