车身薄壁梁结构刚度特性的仿真研究

A Simulation Study on Stiffness of Thin-walled Beam Structure for Automobile Body

将车身薄壁梁截面参数对其弯曲刚度和扭转刚度的影响进行定量分析和性能优化意义重大。以车身薄壁梁的刚度质量系数SME作为评价指标,通过对典型闭口和开口截面梁的分析,得到了薄壁梁截面参数与SME的解析表达式。利用HyperMesh软件进行有限元仿真计算,对定量化表述的理论公式进行了验证,并提出基于刚度特性优化的薄壁梁截面设计原则。把该设计原则应用在某车型白车身上,比较整车弯曲SME值和扭转SME值的前、后变化,得到了更优的整车刚度水平。

The quantitative analysis and performance optimization of the effect of thin-walled beam section parameters on its bending and torsion stiffness are very important. Taking the Stiffness Mass Efficient （SME） into consideration, the analysis of typical closed and open section beam, relation between sectional parameters of thin-walied beam and its SME was derived. FEM simulation was carried out in HyperMesh and proved that the theoretical derivation was correct. Then, the stiffness optimization based design principle of thin-walled beam section was proposed. This design principal was applied to a white body, and comparing the variation of bending and torsional SME before and after modification, a better level of stiffness of the white body was observed.