Dynamic Analysis of a Series Iwan Model Derived From a Continuous Frictional Interface

Abstract

Reduced-order models for characterizing friction interfaces have been investigated for the last 75 years. Recent work has been focused on microslip formulations of the interface behavior, where a continuous interface is approximated with a multipoint contact model. A novel multipoint friction model is presented in this work, which is entirely derived from a shear-lag approach to resolve the kinematic state of the friction interface under the presence of tangential loading. Both static and dynamic loading conditions are analyzed and comparisons are drawn between the continuous and discrete models. The series Iwan model presented in this work differentiates between the elastic and friction components of the interface displacement, both parameters being calibrated using material properties and model geometry. The response characteristics of the series Iwan model under dynamic loading conditions are also investigated. The series Iwan model is in good agreement with the shear-lag approach for results such as propagation of the slip zone with increasing pullout force. The transient response of the structural mass and the kinematic states of the Iwan elements are convergent with increasing model order. A direct physical correlation between the response of the series Iwan model and kinematics of the continuous interface is developed, which greatly enhances the appeal of this particular model for simulating interface phenomena.