Research On Application Of Foam Aluminum Sandwich Plate In Crashworthiness Of Automotive Side Impact

In recent years,the number of car traffic accidents with the increase in car ownership also showed a trend of growth.Among them,the side of the collision accident has been more than a frontal crash,as the main form of car traffic accidents.Side collision accident occurs,often due to the side of the vehicle structure buffer space is small,poor collision performance,resulting in collision can not guarantee the occupant's living space,resulting in serious casualties.In order to improve the crashworthiness of the car in the side collision accident,this paper studies the method of applying the aluminum foam sandwich material to the body parts,and improves the collision resistance of the vehicle by structural design and optimization.First of all,according to the study of automobile safety regulations,this paper establishes the simulation test of automobile side touch with ECE R95 as the standard.Through the results of the simulation test,it is found that the B-pillars are the main body parts that bear the impact force when the vehicle side is touched,and the B-pillar is the important load-bearing part of the door,the threshold and the roof.Therefore,it is possible to improve the impact resistance of the vehicle by improving the crashworthiness of the B-pillar.Secondly,in order to study the properties of foam aluminum sandwich plate and its finite element model modeling method,foam aluminum and foam aluminum sandwich plate samples were prepared.Through the quasi-static compression test,it was found that the foamed aluminum material had three-stage stress-strain trend,and the foamed aluminum material and the foamed aluminum sandwich plate material showed a yield stage after the elastic change.Moreover,it was found that the foamed aluminum interlayer was higher than the foamed aluminum core.According to the stress and strain curves of the foamed aluminum core,the finite element model of the foamed aluminum core was established in LS-DYNA.The connection between the core and the outer plate was simulated by the method o f fixed connection.The stress and strain curves of the finite element model of the foamed aluminum sandwich plate are compared with the stress-strain curves obtained by the actual compression test to determine the effectiveness of the modeling method.After confirming the effectiveness of the modeling method,the foamed aluminum sandwich plate material was used to reconstruct the body B column,and the B-pillar finite element model with the foam aluminum interlayer as the outer plate was established.Then,the size of the B-pillar structure is chosen as the design variable.Based on the establishment of the approximate model,the B-pillar size is optimized by the combination of the quadratic programming algorithm and the multi-island genetic algorithm.The results of material improvement and size optimization show that the maximum incursions of B-pillars are reduced by 9.5%,the intrusion rate is reduced by 4.9% and the quality of B-pillars is reduced by 2.5%.Finally,this paper verifies that the improved B-pillar does not cause the decrease of the compressive performance of the car roof,but improves the compressive performance.This study shows that the use of foam aluminum sandwich board material in the automobile body B column structure can improve the vehicle side collision crashworthiness and car roof compression performance,and can reduce the quality of the body for the foam aluminum sandwich material in the body Resistance to improve the application of the contribution made.