Research On Topological Configuration Design Of Energy Absorbing Structures

In recent years,how to improve the crashworthiness and lightweight of energy-absorbing structures has become a hot topic.But for now,majority of existing studies on the energy-absorbing structures have concentrated on those with a uniform wall thickness and/or a pre-defined sectional configuration.First,most of existing thin-walled structures optimization approaches are based on specific cross-sectional configurations,which are restrictive for generating more general structure configurations.Second,a uniform thickness of thin-walled structures may not necessarily make the best use of the material for meeting the requirements of crashworthiness and structural lightweight.Therefore,how to rationally design the cross-sectional configurations and material distribution of energy absorbing structures to maximize their crashworthiness is a key issue for researchers.In order to provide some useful methods for topological configuration design of energy-absorbing structures,and develop a series of new energy-absorbing structure,this paper carried out the research on topological configuration design of energy absorbing structures.In this paper,an improved orthogonal discrete optimization method was developed for the typical discrete optimization problems in the crashworthiness research of automobile body.Then,the non-linear topological configuration design of energy-absorbing structures was systematically studied.The work of this paper mainly includes the following four parts:First,Multi-objective discrete crashworthiness optimization based on successive orthogonal method: This paper firstly proposes a two-stage design method(first,select the best solution,then further optimize it)to generate an optimal to pological configuration for crashworthiness design of foam filled multi-cell tubes.Then in order to solve the multi-objective discrete optimization problem better,this paper presents a variable step size multi-objective successive orthogonal algorithm,and uses this method to study the discrete optimization of energy-absorbing structure based on crashworthiness.Second,topological configuration design based on intelligent algorithm: In order to better optimize the cross-section configuration and material distribution of energy absorbing structures,a discrete topological configuration optimization method based on intelligent algorithm is proposed in this paper.This method is applied to generate the best possible design of multi-cell tubes and stiffened plates for crashworthiness and anti-explosive performance.The results show that the proposed algorithm not only provides a useful method for discrete topology of energy absorbing structures with variable thickness,but also develops a series of new thin-walled topologies.Third,multi-cell topological configuration design based on discrete surrogate model: A discrete optimization strategy based on Kriging model is proposed for multi-cell topological configuration design involving large non-linear deformation.To improve the computational efficiency,the strategy presents a multiple-point adding criterion based on non-dominated individuals sorting policy.Several standard test functions are used to test the performance of the proposed strategy.And then the optimization strategy is applied to the multi-cell topological configuration design problem.Fourth,topological configuration design of energy absorbing structures based on element energy: A topology optimization algorithm based on element energy is proposed in this paper.And this method does not need sensitivity analysis by gradient derivation.The elemental energy density is used to optimize structural thickness distribution of geometrical and material nonlinear structures.Firstly,this method is successfully applied to the design of multi-tube and automobile bumper.Then the method is applied to the topographical design of stiffened plates under explosive loading.Numerical results demonstrate that the proposed optimization method is capable and effective to achieve the best material distribution for the crashworthiness of energy-absorbing structures.