基于相对灵敏度的车身结构模型修改

应用单元应变能密度理论结合实际白车身结构,提出了车身部件的应变能密度比质量灵敏度的相对灵敏度概念。基于承载式车身有限元模型进行了白车身薄壁构件的相对灵敏度分析,对计算数值进行比较,数值较大的部位即为需要增加厚度的部位,反之则减小厚度,以达到高刚度、轻质量的修改要求。根据相对灵敏度分析得出的修改方向提出了三种不同目标的修改方案:高刚度方案、轻质量方案及综合方案。通过对静刚度的结果对比,可以看出用综合方案得到的是较为符合设计要求的白车身结构模型,并得到了较为满意的修改效果。

Modification method of autobody structure model based on relative sensitivity

Using the element strain energy density theory, combining with the real body-in-white (BIW) structure, a structure modification method based on the relative sensitivity,i. e. , the ratio of the strain energy density to the mass sensitivity, was proposed. In accordance with a finite element model of a BIW,the relative sensitivities of the all thin-walled components of the BIW were calculated and the results were compared each other. The components with higher relative sensitivities need to increase their thickness, otherwise to decrease it, to achieve the structure with high stiffness and light weight. There modification schemes to achieve different targets were presented from the analysis based on the relative sensitivity: high stiffness scheme, light weight scheme, and trade-off scheme. The comparison on the results of stalic sliffness calculation showed that the trade-off scheme leads to a satisfactory modification results, is the best BIW structure model to neet the design requirements.