Research And Optimization On Rollover Performance Of Minivan Based On MADYMO Multi-rigid Body Model

In recent years,there has been a rapid increase in domestic SUV and MPV ownership.The number of extraordinarily serious safety accidents in Minivans has caused a lot of attention in China.The Ministry of Public Security has included Minivans as key models for prevention and control in the next decade.In 2014,the China Machine Center submitted the “Some Suggestions on Combating and Improving Safety of Van's Safety Regulations “to the Ministry of Industry and Information Technology,which proposed the research and establishment of safety standards for Minivans.In order to cope with roll-out related standards,it is of great significance to improve the core competitiveness of auto enterprises.This article takes a minivan as the research object,and explores the test method,simulation,rollover performance and optimization algorithm involved in roll collision.(1)The explosion of Vehicle rollover test methods: In response to the lack of domestic tumbling laws and regulations,the minivan tumbling test capability was established to respond to the implementation of relevant laws and regulations.Combining with the current domestic roll test capability,the target vehicle model tests are performed on platform rollover,screw rollover,side rollover,and top pressure,etc.Finally,this study determines that the platform rollover test method is used in this study.Based on FMVSS 208 regulations,an improvement plan for the platform tumbling test program was proposed,the vehicle counterweight before the test was improved,and the intrusion amount of the vehicle body and the key structural movement parameter test content were increased.(2)Simulation analysis of tumbling crash simulation of minivan: For the shortcomings of the finite element simulation time-consuming calculation,using a mini vehicle as an example,Using MADYMO software to establish a refined multi-body model.The body is divided into a suspension system,a deformable upper body,and a rigid lower body,and a detailed modeling method for each part is provided.The model parameters were determined based on the finite element simulation model,suspension test,and tire impact test.The upper body fine model was calibrated by the results of top pressure test,and the accuracy of the MADYMO model was verified by tumbling test results.(3)The research on the law and factors affecting of rollover characteristic: According to the results of experiments and simulations,four response parameters,namely the maximum flip angle of the center of mass,the maximum value of the linear velocity,the maximum value of the angular acceleration,and the number of turns,were selected to reflect the rollover characteristic of the vehicle.Through the joint simulation of finite element and refined multi-rigid bodies,the single-factor study of vehicle parameters: center of mass height,body height,vehicle wheelbase and initial test conditions: platform angle,initial lift speed,baffle height,and lift-off height for the influence.of rollover characteristic.(4)Tumble crashworthiness optimization of vehicles: For the problem of excessive intrusion of the top and side of the vehicle in the tumbling test,the key structure is determined by analyzing the deformation,the stress cloud diagram,force transfer path,and specific energy absorption of the top structure.Design and change the critical structural material and thickness of finite element through Latin sampling test,extract the relationship curve of M-?,and give it to the refined multi-rigid body model for calculation.The rollover crashworthiness optimization scheme for the top structure of the target vehicle model is proposed,and the optimal scheme is selected for simulation verification calculation,and the simulation optimization effect is significant.