Performance Analysis And Door Lightweight Optimization Based On Parametric Method

Car doors,as an important part of the vehicle,almost occupy the entire body of the side,and its performance directly affects the performance of the whole vehicle.Therefore,It is quite necessary to do the simulation analysis of car doors,find and correct their defects in time.In addition,the door takes a large proportion in the whole vehicle weight and reducing the door weight is of great help to lessen the overall weight.However,the previous door lightweight research only optimize the thickness of the door plate,not focusing on the shape and position of the door parts,which have great influence on the door performance.So it is of great significance to study the lightweight optimization based on shape,position and thickness of car doors.This paper takes a domestic car door as the research object,analyzing the modal,lateral stiffness,the outer surface of the plate and the concave resistance firstly based on the traditional finite element method.The paper is mainly for the following two purposes: for one thing,it is to check whether the structural design of the door is reasonable;for another thing,it provides some references for other door performance analyses based on parametric method.The results show that the surface rigidity of the outer panel is unqualified;the rigidity of the door surface is improved after remodeling the door structure and other performance indexes of the door meet the design requirements.Secondly,the door performance analysis was carried out based on the parametric method.The parametric geometric model and parameterized finite element model of the door are established by using the parametric software SFE-Concept,and the modal and lateral stiffness analysis of the door are carried out.By comparing and analyzing the door performance data calculated by the traditional finite element method,The reliability of the parametric model is verified.On the basis of this model,the influence of the door handle arrangement on the door performance is also studied.Finally,the single-objective optimization of the door structure is carried out based on the parametric method.The first order bending mode frequency,the first order torsional modal frequency and the lateral stiffness are taken as the constraints.And the five thickness variables and the four shape variables are taken as the main design variables.The approximate model is established based on the highest accuracy of the model.Finally,the approximate model of each output response is defined as the radial basis function model,and the accuracy of each approximation model is evaluated by using the optimized Latin hypercube test design method.Then,the hybrid integer sequence quadratic programming method(MISQP)is used to solve the single weight optimization problem of the door,and the simulation results are verified.The results show that the approximate model is reliable.And without reducing but improving a little the performance of the door,the weight of car door is reduced bby 0.58%.In order to further reduce the weight of the door,this model forces to thinen the thickness of some door parts,and make some manual adjustments according to the engineering experience,which successfully solve the decline problems in car performance caused by thinner door parts.The results of the final simulation show that,with all the performance indexes unchanged or even improved,the weight of car door is reduced by 648g(3.50%),which also means the effect is quite obvious.