Mode II modeling of adhesive materials degraded by fatigue loading using cohesive zone elements

Abstract

Because of maintenance issues, the concept of safe life is an important philosophy for designing adhesive joints where the service load is cyclic. However, this philosophy needs a tool to be able to estimate the total fatigue life. The objective of this study is to develop a numerical tool to predict the fatigue life of adhesive joints for pure mode II loading conditions. To achieve this, a previously published mode I data degradation approach was extended for pure mode II. Fatigue tests were performed on end notched flexure (ENF) specimens to calibrate the degradation model. A triangular shape cohesive zone model (CZM) in combination with a data degradation method were considered in an Abaqus user element (UEL) subroutine. Based on the results, it was found that the proposed method can be applied for fatigue life estimation of adhesive joints in pure mode II conditions as well as pure mode I.