基于小偏置碰的乘员二次碰撞分析及约束系统仿真优化

Occupant secondary impact analysis and restraint system simulation optimization under small offset impact

研究64 km/h小偏置碰的乘员动态响应及约束系统参数影响。通过建立50 km/h全正碰与64 km/h小偏置碰的约束系统模型,比对两种工况中的乘员二次碰撞运动姿态与损伤特点。仿真结果表明小偏置碰中乘员上躯干相对车体产生较大的横向加速度,导致头部和颈部等部位损伤加剧。基于上述损伤特点,导入侧气帘模块并分析其对乘员损伤的影响;优化驾驶员侧气囊袋形并通过代理模型方法匹配其参数。CAE优化结果显示小偏置碰中假人头部HIC 36和颈部N ij分别降低61.75%和31.3%,加权损伤指标(WIC)降低了47.22%。

Here,vehicle occupant dynamic responses and influences of restraint system parameters were studied under 64km/h small offset impact.Restraint system models under both 50km/h full frontal impact and 64km/h small offset impact were established,and the movement posture and injury characteristics of occupant in the secondary impact under the two working conditions were compared.The simulation results showed that occupant’s upper body relative to the vehicle body has larger lateral acceleration under small offset impact to cause occupant’s head and neck damage aggravated.Based on the above damage characteristics,a side air curtain module was introduced and its effects on occupant damage were analyzed,the shape of the driver’s side airbag was optimized and its parameters were matched with the surrogate model method.CAE optimization results showed that under small offset impact,the dummy’s head HIC36 and neck Nij are reduced by 61.75%and 31.3%,respectively,and its weighted injury criteria(WIC)is reduced by 47.22%.