某车型拖曳臂支架强度开裂分析与改进

Analysis and Improvement of Strength for Trailing Arm Bracket

某车型在强化路试行驶里程达7200km时,车身拖曳臂安装支架出现撕裂现象,严重影响产品的质量和安全。为了找出安装支架开裂的根本原因,基于Hypermesh软件建立支架的有限元模型,采用惯性释放方法针对支架三种危险工况进行强度分析,结果表明支架在制动和转弯工况下其强度存在较大风险,最大应力为518.6MPa,撕裂部位发生在支架本体根部,这与整车道路试验结果吻合。对支架结构设计优化,通过改变结构形状、材料和厚度,分析结果表明结构优化后,支架结构的强度得到了较大提升,尤其是制动和转弯工况。通过提高支架的刚度和分解支架的载荷,能够改善结构的应力水平和分布,避免结构设计上的局限而引起强度不足的风险,在工程上具有较大参考意义。

When a QX vehicle was running in a road test about 7000km for reliability, a bracket which was mounted on trailing arm appeared tearing, which had seriously affect on the product quality and safety. In order to find failure cause, a finite element model was building with Hypermesh, and inertia relief method was applied to analysis the bracket strength for three dangerous working condition. The result has shown that the bracket strength was insufficient when it worked in wheeling and breaking, and the tearing position and magnitude （518.6MPa） of maximum stress were consistent with road test. The bracket was redesigned that structural shape, material and thickness were optimized. The optimization result shown that strength had great improvement for wheeling and breaking especially. By increasing stiffness of the bracket and decomposition of load, the stress level and distribution of structure could be improved, and the limitation of insufficient strength in structure design could be avoided. It will be of great significance in engineering.