Crashworthiness Analysis,Optimization And Application,Research Of Large Deformation Structure

Large deformation mainly refers to the transportation vehicle safety-problems resulting in the collision has been an important research direction,how to strengthen the vehicle structure deformation crashworthiness has become a safety study in the field of an important part of.As the most important crashworthiness component of large deformation structure,thin-walled metal component is closely related to its geometric size and cross sectional shape in impact impact.Therefore,this paper through the research of thin-walled members with the above factors,the finite element method,show the response surface approximation model and the asymptotic structure optimization method for thin-walled structures and truss structure of Crashworthiness optimization based on.The main research work of this paper is as follows:1)Based on the response surface approximation theory,the geometry optimization of the crashworthiness of thin-walled members is studied.The finite element simulation of thin walled tube rigid wall collision,collision force displacement curve,test the accuracy of the model by numerical solution theory;with specific energy absorption as the objective function,the establishment of four response model of T and B thick section length.The optimal solution of specific energy absorption is obtained by fitting calculation.The error comparison between the calculated values and the finite element values shows that the proposed method is accurate and effective for the crashworthiness optimization of thin-walled tubes.2)Based on the thin-walled square tube,considering the crashworthiness and lightweight requirements,two thin-walled rectangular tubes with four cell and four flanges are designed.The optimal model and parameters of two cross sections are obtained by optimal design.Compared with the thin walled square tube,the specific energy absorption of the two section tubes is greatly improved,and the four cell section has better energy absorption effect.It shows that choosing the appropriate section shape can improve the crashworthiness of the component.3)Based on the progressive structural optimization method,the crashworthiness optimization of truss structures subjected to axial impact loads is investigated.The strain energy and deformation of truss structure are obtained by finite element simulation.The efficiency of material is defined by the ratio of each element to the maximum strain energy,and the specific energy absorption is used to determine whether the truss meets the optimization requirements.Numerical examples show that it is feasible to carry out topological optimization of truss structures by using progressive structural optimization method.4)The bus rollover crashworthiness optimization analysis as an example,using the above research results,the thin-walled member size,shape optimization and topology optimization of truss structure optimization method is applied to the analysis of bus body structure,and achieved good results.A column thin walled beam structure with stiffened columns of special shape is proposed.Compared with the simulation results of thin-walled square tubes,thin walled square tubes and foam aluminum filled square tubes,it is proved that the structure has better crashworthiness.Based on response surface method,the shape parameter optimization of square tubes with equal strength is optimized,and the optimal solution of specific energy absorption is obtained.The utility model can be used as a reinforcing member of a bus body upright column,and has high popularization value.The establishment of a set of bus rollover deformation crashworthiness optimization design of the system,through the finite element modeling,simulation,test sample design,approximate model,optimization and test validation,for vehicle rollover crashworthiness optimization design research.After optimization,the bus successfully passed the Rollover Safety Test certification.The successful engineering application of the cooperative project shows that the method presented in this paper is feasible and effective,and the crashworthiness of the large deformation structure is improved.It has important engineering application value.