Crashworthiness And Structural Improvement For B-pillar Based On Welding Technology

China’s urban traffic contains many cross intersections,thus leading to thefrequently occurrence of side impact, accounting for about one-third of the totalnumber of traffic accidents. The side body structure is less Crashworthiness whencompared with front and rear part of body structure,and it’s also closer to passenger.After the side impact,passenger would be oppressed and shocked caused by bodyretraction because of the small occupant space. As the main body side part towithstand and transmit the force of the collision, B pillar has a greater contribution tostructural the entire side crashworthiness. Whose intrusion and the intrusion velocityreflects the degree of damage to the vehicle occupants from indirect sources,and it’sdeformation mode also determines the injured site of the occupants. In addition, toreduce its retraction by simply increasing the stiffness of the B-pillar will hinder theits absorption of collision energy, and also inconsistent with the concept oflightweight body. Therefore, deformation mode of B-pillar should be underreasonable control in improvements, to reduce the degree of occupants injury during acollision.This article aims to optimized design the crashworthiness of B-pillar by usingtailor-welded blank structure. Control the intrusion and the intrusion velocity toachieve the occupant protection in side impact on the basis of light weight of B pillarassembly. Firstly,build the finite element simulation model of side impact and verifyits validity, assess the safety of this vehicle by the output curve and determine thedeformation mode of the B pillar of the vehicle. Compare the mechanical propertiesof tailor-welded blank with different thickness,and get the ratio of the safe range.Finally, use tailor-welded blank instead of the initial one to optimized design the B-pillar which use metal thickness and weld location as the design variables. Sample byorthogonal experimental design,use polynomial response surface model as a agentmodel, obtain the optimal solution by sequential quadratic programming. The mass ofoptimized B-pillar assembly decreased by15.2%, intrusion and intrusion velocitydecreased by10%and5.2%，and the deformation modes is perfect.The results show that the use of tailor-welded blank stamping as the materials ofB-pillar and optimized design its parameter can get can be an ideal B-pillar deformation mode improving side impact safety performance while maintaining itslightweight. The thoughts and optimization method in this study is feasible in bodystructure design and improvement,which has a certain reference value forcrashworthiness research.