考虑螺栓预紧力作用范围不均影响的结合面刚度识别

Stiffness identification of joint surface by considering the influence of uneven action range of bolt preload

螺栓连接结合面的刚度和阻尼的变化会引起整个螺栓连接结构的动态特性变化,准确得到结合面动态参数在工程中具有极大的实用价值。基于螺栓连接结构,提出螺栓预紧力作用范围内结合面刚度分布不均的结合面等效改进模型,并对有限元建模中不同数量刚度矩阵单元分布作出分析。采用实验与有限元分析相结合的方法对螺栓连接结合面进行刚度参数辨识。结果表明:在一定程度上,增加刚度矩阵单元数量可以提高固有频率解的精度。同时考虑螺栓预紧力作用范围内结合面刚度分布不均,可以有效地提高螺栓连接结构的等效建模精度。

The changes in stiffness and damping of the bolted joint surface can cause the changes of dynamic characteristics of the whole bolted joint structure,so it is of great practical value to accurately obtain the dynamic parameters of the joint surface in engineering.Based on the bolted structure,an improved equivalent model of the stiffness of the joint surface with uneven distribution in the range of bolt preload was proposed,and the distribution of different stiffness matrix elements in the finite element modeling was analyzed.The stiffness parameter identification of bolted joint surface was carried out by combining experiment and finite element analysis method.The results show that the increase of the number of stiffness matrix elements can improve the accuracy of natural frequency solutions to some extent.At the same time,considering the uneven stiffness distribution of the joint surface in the range of bolt preload,the equivalent modeling accuracy of the bolted joint structure can be effectively improved.