The nonlinear mechanics modeling is proposed to describe the nonlinear stiffness of the bolted joint interfaces induced by the stick-slip friction behaviors. By combining the microscale contact mechanics of the asperity interaction, the statistical analysis of the non-Gaussian surfaces is conducted to extract a four-parameter model to characterize the nonlinear softening stiffness and residual stiffness of the bolted joints. The Masing principle is then implemented to model the tangential hysteresis nonlinearity of the oscillatory loading process. Comparison with the experimental results of a lap-type bolted joint is performed to validate the proposed model and investigate the effects of the bolt preload. The results show that the proposed model can be used to simulate the nonlinear stick-slip behaviors of the bolted joint interfaces, and the prediction of the model parameters agrees well with the identification of the experimental results. Larger bolt preload will induce a larger critical stick-slip force, stronger nonlinearity, and better symmetry of the hysteresis nonlinearity, but hardly affect the residual stiffness.

中文翻译：

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非高斯曲面螺栓连接非线性刚度的四参数模型

提出了非线性力学模型来描述由粘滑摩擦行为引起的螺栓连接界面的非线性刚度。通过结合凹凸相互作用的微尺度接触力学，对非高斯曲面进行统计分析，提取四参数模型来表征螺栓连接的非线性软化刚度和残余刚度。然后实施 Masing 原理来模拟振荡加载过程的切向滞后非线性。与搭接式螺栓接头的实验结果进行比较，以验证所提出的模型并研究螺栓预紧力的影响。结果表明，该模型可用于模拟螺栓连接界面的非线性粘滑行为，模型参数的预测与实验结果的识别吻合较好。螺栓预紧力越大，临界粘滑力越大，非线性越强，滞后非线性的对称性越好，但对残余刚度影响不大。