基于外推法的后副车架焊缝疲劳耐久分析∗

摘要

Based on extrapolation method of structure hot-spot stress,the weld fatigue damage of a rear sub-frame is ana-lyzed. FEA model of rear sub-frame is established, and critical weld position is ascertained according to strength analysis re-sult of the whole rear sub-frame. Weld structural hot spot stress is extrapolated by using sub-model skill of ABAQUS and ex-trapolation method of international institute of welding ( IIW) . Finally, weld fatigue calculation programs referred to 'Eurocode 3:part1-9 Fatigue' is compiled to compute weld damage. The results show that the weld fatigue damage has reached the fa-tigue life needs.%基于焊缝结构热点应力外推法对后副车架焊缝进行疲劳分析。建立某后副车架有限元模型，根据后副车架总体模型强度分析结果识别关键焊缝位置，再利用ABAQUS子模型技术及国际焊接学会( IIW)外推方法计算焊缝结构热点应力，最后使用MATLAB语言根据《Eurocode 3：part1-9 Fatigue》编写焊缝疲劳计算程序进行损伤计算。计算结果表明：通过外推法计算的焊缝损伤值满足疲劳耐久设计要求。