考虑顶压与侧碰安全性的轿车车身B柱结构优化设计

Structural Optimization Design of B-pillar Considering Roof Crush and Side Impact Requirements in Passenger Car

综合考虑车顶强度和侧面碰撞的安全性能,对某型轿车的B柱结构进行了优化设计。采用高强度钢结构和拼焊板技术将B柱内外板分成上下两部分进行焊接。将4块拼焊板的高强度钢选型和厚度作为离散设计变量,同时对材料成本、车顶最大承载作用力、B柱侵入速度和侵入量进行约束,建立了B柱结构优化的数学模型。采用移动最小二乘法构造近似模型,结合遗传算法对B柱拼焊板结构进行了优化设计。结果表明:在材料成本基本不变的情况下,B柱结构总质量减小了13.8%,B柱侵入速度、侵入量分别减小了5.6%和3.8%,车顶承载能力提高18.53%,有效地提高了车顶强度和侧面碰撞的安全性能。

The optimization design ol B-pillar was carried out by considering tne roof strength and the safety of side impact. The inner plate of B-pillar,as well as the outer plate, consisted of two different parts which were welded together by tailor-welded blank technology and formed by high strength steel. The type of material and the thickness of steel were treated as discrete design varia- bles. The optimization model of the structural crashworthiness of B-pillar was established by consid ering the material cost, the impact force,the intrusion and its velocity at B--pillar. The moving least square response surface and genetic algorithm were utilized to improve the crashworthiness of B-pil- lar. The results show that the intrusion and its velocity at B-pillar are reduced by 3.8% and 5.6 % respectively. The roof strength is enhanced by 18.53% and the mass is reduced by 13.8% ,while the material cost is unchanged. Thus, the roof strength and the safety of side impact are improved effec- tively.