Lightweight Design Of Front Door Based On Structure And Safety Performance

As a powerful way to reduce energy consumption and pollution emissions,automobile lightweight has increasingly become a research hotspot in the automotive industry.As an important part of the vehicle,the rigidity and crashworthiness of the door have a greater impact on the performance of the vehicle.The lightweight of the door is a complex problem with multiple parameters and multiple working conditions.The previous lightweight is often based on part of the work.The conditions were optimized without comprehensive consideration of the structure and safety performance of the door.Therefore,based on the rigidity and crash safety of the door,the lightweight design of the door under multiple working conditions has certain research significance.This paper takes a passenger car as the object,and studies the lightweight design of the front door of this model according to the performance requirements of the door’s modal,rigidity,strength and crash resistance.The main research contents of the paper are as follows:(1)Firstly,the finite element model of the left front door is established,and the modal analysis conditions of the door are constructed according to the corresponding specifications for analysis,and the modal vibration shape of the door is judged to provide performance reference for subsequent optimization.(2)In order to comprehensively evaluate the structure and safety performance of the door,in accordance with relevant analysis standards,establish the corner stiffness of the door and window frame,the stiffness of the window frame,the sag stiffness,the waistline stiffness of the inner panel,the waistline stiffness of the outer panel,the upper torsional stiffness and the lower torsional stiffness,etc.Analyze the working conditions to determine the rigidity performance of the original door,and at the same time provide optimization targets and constraint conditions for the subsequent lightweight design.Refer to GB15743-1995 to build the strength analysis condition of the car side door,analyze the performance of the door strength,and judge whether the strength meets the standard.With reference to Euro-NCAP,an analysis model of side column collision was established to analyze the crashworthiness of the original door.(3)From the door strength analysis,it can be seen that the strength of the original door of this model is poor,and there is room for optimization.Based on the door strength analysis to determine the test factors,indicators and the level of each factor,the orthogonal experimental design and simplified model method are used to optimize the initial compression force of the door,so that the door meets the strength under the premise of lower weight gain.(4)Based on the existing modal and stiffness results,the goal and constraints of the door lightweight are determined.Carry out sensitivity analysis on the thickness of door components,calculate the relative sensitivity of each component’s performance to quality,select 7 key components as optimization variables based on the relative sensitivity results,use Optistruct to complete the parameter optimization,and obtain the optimized plate thickness parameters,and verify the performance of modal,stiffness,strength and crashworthiness of the lightweight scheme.