LAUSR

Abstract 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.