基于柔性部件载荷提取的前副车架疲劳分析

Fatigue Analysis on Front Subframe with Extracted Loads Based on Flexible Parts

以准确的耐久道路谱作为动力学分析的边界条件,分别建立刚性和柔性部件的多体模型,提取前副车架连接点载荷谱。分别以两种载荷谱为输入,对前副车架的本体和焊缝进行疲劳分析。研究发现,基于刚性和柔性部件提取的载荷数据在幅值、均值、离散性和相对伪损伤方面均有很大差别。载荷二轴性分析显示,前副车架应选择多轴疲劳分析方法。相比而言,基于柔性部件提取载荷,本体多轴疲劳分析结果与试验情况更吻合,焊缝损伤最大位置和循环次数也与试验结果非常接近。

A dynamics analysis was conducted under the boundary conditions of accurate load spectrums of durable roads.Two multi-body models were built respectively for flexible and rigid parts. Load spectrums of front subframe were extracted at all connection points. With these two load spectrums as the inputs, fatigue analysis on main parts and seam welds of front subframe was carried out. The results show that loads extracted based on rigid and flexible parts have a large difference in amplitude, the average value, discrete properties and the relative pseudo damage. A multiaxial fatigue analysis is proposed for the front subframe according to the biaxial analysis of loads. By contrast, for the loads based on flexible parts, the results of multiaxial fatigue analysis for the main part are more consistent with the test results. And also the predicted damage area and life cycles of the seam welds agree with the test results.