中文摘要：

针对螺栓有限元分析建模困难和不完整螺纹造成计算精度不高的问题，分别采用三维螺旋模型和三维轴对称简化模型进行有限元计算，分别比较分析了对应各固螺纹沿外轮廓方向的应力分布和螺纹牙根部最大等效应力。结果表明，两种模型均可较精确地计算出螺栓螺纹上各节点的应力，但三维螺旋模型法建模较困难、计算成本较高，三维轴对称简化模型法的计算结果能较好地反映螺栓的轴向力学特性，研究结果为改进螺栓连接受力状况和结构优化设计提供了理论依据。

英文摘要：

According to the modeling difficuhies and imprecision caused by incomplete thread in the process of finite element analysis for bolt, a spiral modeling method and a simplified three--di- mensional axisymmetric modeling method were adopted separately. By comparing the results of stress distribution on each circle of the screws and the maximum of equivalent stress at the roots of the threads calculated from two different numerical models, the reasons for the difference between the two different modeling methods were obtained. The results show that both of the two methods have preferable precision, which ensure accurate analysis of the stress distribution on each node of bolt threads, while the modeling of the spiral modeling method is more difficult. In comparison, the re- suits of the three--dimensional axisymmetric modeling method can reflect the mechanical properties of the axial bolt preferably, and provide the theoretical basis for optimal design of structures.