This paper presented a non-linear modeling approach for bolted joint connection interfaces and identified the micro-slip model’s parameters through quasi-static experiments based on an improved micro-slip model. Firstly, considering the contact pressure’s spatial distribution characteristics on the connection interface, a new density function of critical sliding force was proposed. The contact pressure is distributed annularly on the interface. Then, the critical sliding force’s density function was applied to the Iwan model, and an improved micro-slip model was proposed. The residual shear stiffness on the connection interface during macro-slip and separation was also taken into account simultaneously. The piecewise linear model and the improved micro-slip model were adopted to reproduce the different tensile and compressive stiffness of the bolted joint and the friction on the interface, and the non-linear mechanical model of the bolted joint was obtained. Finally, this paper proposed a method for parameter identification of the micro-slip model on the connection interface. The hysteresis loops were obtained through quasi-static shear experiments, and corresponding parameters were identified.

本文提出了一种螺栓连接接口的非线性建模方法，并通过基于改进的微滑移模型的准静态实验确定了微滑移模型的参数。首先，考虑到连接界面上接触压力的空间分布特征，提出了一种新的临界滑动力密度函数。接触压力呈环形分布在界面上。然后，将临界滑动力的密度函数应用于Iwan模型，并提出了一种改进的微滑动模型。同时还考虑了宏观滑动和分离过程中连接界面上的残余剪切刚度。采用分段线性模型和改进的微滑移模型，再现了螺栓连接的不同拉伸和压缩刚度以及界面上的摩擦力，得到了螺栓连接的非线性力学模型。最后，本文提出了一种用于连接界面上的微滑模参数识别的方法。通过准静态剪切实验获得了磁滞回线，并确定了相应的参数。