汽车碰撞中低压线束的失效评价方法研究

Research on Failure Evaluation Method of Low Voltage Cables in Vehicle Crash

为了获得汽车碰撞过程中低压线束较为准确的失效评价方法,选择现有车型中使用较多的16 mm^(2)、25 mm^(2)、35 mm^(2)3种不同截面尺寸的低压线束,根据整车中线束受到的挤压情况,设计M10螺栓、5 mm钢片、20 mm钢片3种挤压头进行了试验研究,结果表明,挤压速度对线束的挤压破损失效影响很小,线束的变形压缩比可以作为线束前期碰撞保护设计的评价指标。进一步通过CAE仿真与试验结果的对比研究,确定了双层六面体单元的CAE建模形式,同时考虑整车CAE计算效率,选择3 mm的CAE单元网格尺寸。最终,给出了低压线束碰撞失效评价的CAE分析方法和量化指标。

In order to obtain an accurate failure evaluation method of low-voltage cables in the vehicle crash,3 kinds of low-voltage cables with different cross-section sizes including 16 mm^(2),25 mm^(2),and 35 mm^(2) are selected,that are commonly used in current vehicles.According to the extrusion of cables in the vehicle,3 kinds of extrusion heads are selected,namely M10 bolt,5 mm steel sheet and 20 mm steel sheet,to perform experimental study.The results show that,the extrusion speed has slight effect on the breakage failure of cables,the deformation compression ratio of the cables can be used as the evaluation index of the advanced crash protection design of the cables.Then by comparative study of CAE simulation and experimental results,the CAE modeling form of double-layer hexahedral element is determined,meanwhile vehicle CAE calculation efficiency is taken into account,and the CAE grid size of 3 mm is chosen.Finally CAE analysis method and quantitative evaluation index of low voltage cables failure evaluation in the vehicle crash are given.