中文摘要：

以某型现役汽车起重机底架钢结构为研究对象,建立起重机虚拟样机模型及有限元静力学模型,分析并获得五个载荷步下的名义应力谱;基于FE-SAFE（durability analysis software for finite element models）耐久性分析软件,用多轴临界平面疲劳损伤模型,采用Brown-Miller准则建立寿命损伤模型,对底架结构的疲劳寿命进行预算。预算结果表明该型起重机底架结构工作约3 062个循环时出现肉眼可见裂纹,而其使用寿命约为70 555个工作循环。其疲劳寿命预算分析为某型现役起重机的实际设计和使用检修提供有价值的参考。

英文摘要：

Taking a certain truck crane in service as the research object,established the virtual prototyping model and finite element model for the steel under-frame structure of the crane,then obtained its nominal stress spectrum under five load steps;also,established life damage model according to the Brown-Miller guidelines,and predicted the fatigue life of the under-frame based on the FE-SAFE（durability analysis software for finite element models） durability analysis software and the Multi-axial critical plane fatigue damage model.The result shows that the usable life of this under-frame is about 70 555 working cycles,and the visible crack may appear after about 3 062 cycles.This can be of valuable reference to the design and maintenance for this truck crane.