螺栓联接的有限元建模方法研究

对螺栓联接的有限元建模方法进行研究和评估.以螺栓-法兰联接为例，基于有限元分析软件ANSYS，建立了3种螺栓联接的有限元模型，即实体螺栓联接模型、梁单元联接模型和刚性单元联接模型.模态试验和应力分析表明，实体螺栓联接模型和梁单元联接模型具有广泛的适用性，可准确分析螺栓联接结构的静态特性和动态特性.相比实体螺栓联接模型，梁单元联接模型在保留了关键细节的同时提高了建模和计算效率.刚性单元联接模型不能模拟螺栓预紧和接触，只适用于模态分析.试验和仿真均表明，螺栓预紧力的大小对结构模态影响很小.仿真表明，螺栓联接表现出复杂的非线性特性，如应力的非线性变化、法兰之间接触状态的变化、螺栓总拉力的非线性变化等. 

Study on Finite Element Modeling Method of Bolted Joints

A finite element modeling method was studied and investigated for bolted joints in this paper. Taking the bolted flange connection as example,three kinds of finite element models,including solid bolt model,beam bolt model and rigid bolt model,were introduced based on finite element software ANSYS. And modal test and stress analysis were carried out. The results show that the solid bolt model and beam bolt model can be used for accurate static and dynamic analysis for the bolted flange connection,and possess wide applicability. Compared with the solid bolt model,the beam bolt model can improve modeling and computational efficiency,keeping key details. The rigid bolt model can only suit for modal analysis,and can''t simulate the bolt pretension and contacts. Both experiment and simulation indicate that the magnitude of bolt pretension has little influence on structural natural frequency and mode shape. The simulation results show that the bolted joints have complex nonlinear behavior,such as nonlinear variation of stress,contact status variation between flanges,nonlinear variation of bolt tension,et a l.