表1　参考线划分结果对比

由表1的对比结果可以知道，所开发的参考线自动划分程序与Oasys软件具有相同的精确度。其最大坐标差值为5.545mm，占法规规定成人头部模型直径的3.3%，在可接受范围内，说明了所开发的程序具有一定精度。

4.2硬点搜索算法验证

将十个碰撞点碰撞仿真进行仿真，如图14所示，然后将仿真后的hic15值进行整理，如表3所示。

图14　头部撞击发动机罩仿真结果

表2　硬点区域与非硬点区域HIC值对比

表中node0至node4为硬点程序搜索结果给出的5个硬点位置，node5至9为在发动机罩上随机选取的位置。由表可知，由硬点搜索程序给出的五个硬点的头部伤害值大体大于非硬点区域头部伤害值，且随硬点距离的增大伤害值有下降趋势，说明自开发硬点搜索程序有较高的准确度和可信度。

4.3自动定位算法验证

为了验证所开发自动定位程序的精确度，将其定位结果，即模型从初始位置至碰撞位置的平移向量，与Oasys软件的定位结果进行比较，如表3所示。

由表3的对比结果可以知道，所开发的头部定位程序与Oasys软件具有相同的精确度。其最大坐标差值为2.412mm，占法规规定成人头部模型直径的1.46%，在可接受范围内，说明了所开发的程序有一定精度。

5 结论

本文是基于HyperMesh二次开发接口所进行的行人保护数值仿真前处理系统开发，它能使分析人员从繁琐、重复、耗时的前处理工作中解放出来，主要实现了行人碰撞区域参考线自动划分、硬点自动搜索并自动生成报告、多目标点冲击器模型自动定位三大功能，大大提高了前处理的效率和精度。

6 参考文献
[1] GB/T 24550-2009《汽车对行人的碰撞保护》　2009.10
[2] 于开平，周传月．HyperMesh从入门到精通[M]．科学出版社，2005
[3]  European Enhanced Vehicle-safety Committee.EEVC Working Group 17 report-Improved test methods to evaluate pedestrian protection afforded by passenger cars.Delft,the Netherlands:TN0 Crash-Sagety Research Centre,1998,6-8
[4] European Enhanced Vehicle-safety Committee.EEVC Working Group 10 Reports-Proposals for methods to evaluate pedestrian protection afforded by passenger cars.Delft,the Netherlands:TN0 Crash-Satety Research Centre,1994
[5] 赵海鸥．LS-DYNA 动力分析指南[M]．北京：兵器工业出版，2003.9

System for Pre-Treatment Work of Numerical Simulation of Automotive Pedestrian Protection

Xu Yuneng    Lu Shanbin   Ye Hui

Abstract：In order to achieve the numerical simulation of pedestrian protection automatically, quickly and accurately prior to the pre-treatment work to replace the duplication, red tape and lower accuracy manual creation of reference line, hard points detection and positioning of model,  this article, which is based on HyperMesh secondary development, according to the requirements of reference line, hard points detection and model positioning of European regulations (Euro NCAP), complete the development of numerical simulation of automotive pedestrian protection system. This automated pre-treatment system is to solve the following problems: the automatic creation of Upper and Lower Bumper Reference Line, Bonnet Leading Edge Reference Line, Bonnet Side Reference Line and Wrap Around Distance, the automatic search of bonnet hard points for the headform, headform to bonnet positioning, legform to bumper positioning, upper legform to bumper and bonnet positioning, it can make the pre-treatment work faster and more accurate.

Keywords：HyperMesh Pedestrian Protection Reference Line Positioning        

                       Hard Points Algorithm