基于Iwan模型的螺栓非线性接触建模与参数辨识

螺栓连接在使用过程中会产生非线性现象，主要包括微观碰磨与宏观滑移等。本文主要建立了基于Iwan模型的螺栓连接结构动力学模型，并通过实验研究实现了模型的参数辨识。引入六参数Iwan模型，对力-位移方程进行数值求解，绘制Iwan模型非线性位移与非线性力关系曲线，解决了传统螺栓连接模型计算精度不高的问题。针对螺栓结构动力学模型参数辨识问题，采用万能试验机拉伸实验与振动实验平台激振试验结合，识别构建的模型参数，实现模型构建。实验结果表明随着螺栓直径的增加，宏观滑移残余刚度会随之增加。研究结果可为螺栓结构设计分析与计算提供参考。

Nonlinear contact modeling and parameter identification of bolts based on Iwan model

Nonlinear phenomena including microscopic friction and macroscopic slippage occur in bolted connections. This paper establishes the dynamic modeling of bolted connection structure based on Iwan model and carries out dynamic and static experiments for parameter identification of the established model. The six-parameter Iwan model is introduced into the bolted connection model. By numerically solving the force-displacement equation and determining the relationship between the nonlinear displacement and the nonlinear force curve of the Iwan model, the problem of low calculation accuracy of the traditional bolted connection structures is alleviated. For the parameter identification of the bolted structure, the universal testing machine is used to carry out the bolt tensile test; the vibration excitation platform is used to carry out the bolt vibration test to obtain the model parameters. The experimental results show that the macroscopic slip residual stiffness increases with the increase of the bolt diameter. The research results will provide reference for bolted structure design analysis and calculation.