钢?CFRP异质复合B柱的弯曲实验分析

目的 为提高B柱的抗弯性能，通常会在B柱上额外焊接补丁板，但同时也增加了B柱的重量。在原始B柱上铺设碳纤维增强复合材料(CFRP)，获得钢?CFRP异质复合B柱，取消B柱的钢制加强板，实现B柱的轻量化。方法 通过热冲压制备原始B柱及带补丁板B柱，并以原始B柱为凹模，采用真空袋压工艺制备钢?CFRP异质复合B柱。基于2018版C?NCAP侧面碰撞实验要求，设计B柱三点弯曲夹具，进行原始B柱、带补丁板B柱及钢?CFRP异质复合B柱的三点弯曲实验，并对其重量及弯曲性能进行分析。结果 原始B柱重量4.1 kg，三点弯曲实验测得其刚度为0.763 kN/mm，最大载荷为21.59 kN，平均力为14.52 kN;带补丁板B柱质量为5.6 kg，三点弯曲实验测得其刚度为1.095 kN/mm，最大载荷为31.08 kN，平均力为18.38 kN;钢?CFRP异质复合B柱总质量4.7 kg，三点弯曲试验测得其刚度为1.071 kN/mm，最大载荷为31.76 kN，平均力为19.58 kN。结论 在保持刚度、最大载荷及平均力等弯曲力学性能不变的前提下，相对于带补丁板B柱，钢?CFRP异质复合B柱可以减轻质量0.9 kg，并且吸能更优，实现了B柱的轻量化。

Bending Test Analysis of Steel-CFRP Hybrid Composite B-Pillar

In order to improve the bending resistance of B-pillar, additional patch plates are usually welded to the B-pillar, which increases the weight of the B-pillar at the same time. The work aims to lay carbon fiber reinforced composite (CFRP) on the original B-pillar to obtain the steel-CFRP hybrid composite B-pillar, and eliminate the steel reinforced plate to realize the lightweight of B-pillar.The original B-pillar and B-pillar with patch plate were prepared by hot stamping. The steel-CFRP hybrid composite B-pillar was fabricated by vacuum bag pressure molding with the original B-pillar as the die. Based on the requirements of C-NCAP side impact test (2018 Edition), a three-point bending fixture for B-pillar was designed, and three-point bending test was carried out to original B-pillar, B-pillar with patch plate and steel-CFRP hybrid composite B-pillar. The original B-pillar had the weight of 4.1 kg, stiffness of 0.763 kN/mm measured by three-point bending test, maximum load of 21.59 kN and average force of 14.52 kN. The B-pillar with patch plate had the weight of 5.6 kg, stiffness of 1.095 kN/mm measured by three-point bending test, maximum load of 31.08 kN and average force of 18.38 kN. The steel-CFRP hybrid composite B-pillar had the total weight of 4.7 kg, stiffness of 1.071 kN/mm measured by three-point bending test, maximum load of 31.76 kN and average force of 19.58 kN. Under the premise of maintaining the bending mechanical properties such as stiffness, maximum load and average force, the weight of steel-CFRP hybrid B-pillar can be reduced by 0.9 kg compared with that of B-pillar with patch plate, and the energy absorption is better, which realizes the lightweight design of B-pillar.