Abstract: In view of the fatigue cracking problem of a bus body frame, through the CAE strength analysis of the bus body under typical working conditions, the stress concentration position is consistent with the cracking position. Mainly concentrated in the front suspension and the cross beam under the tail section safety door. For the weak parts, the methods of local strengthening and rear section stiffness improvement are adopted. The results show that the structural stress of the relevant area is controlled within the fatigue limit, and the durability of the local structure of the bus is improved.

Key words: Body frame; Local cracking; Finite element; Strength analysis; Durability

摘要： 针对某大型客车车身局部骨架疲劳开裂问题，通过对客车车身骨架进行典型工况下的 CAE 强度分析，在相 关工况下应力集中位置与开裂位置较为吻合，主要集中在前悬附近以及尾段安全门下方的横梁上，对于薄弱的地方 采取局部加强和后段刚度提升的方法进行改进优化，将相关区域结构应力控制在疲劳极限以内，改善了客车局部结 构的耐久性。

关键词: 车身骨架；局部开裂；有限元；强度分析；耐久性