A Continuum Damage and Discrete Crack module for Fatigue Damage Prediction of Laminated Composite Structures

Abstract

This study is focused on the development and demonstration of a continuum damage and discrete crack (CDDC) module for damage prediction of laminated composite structures subjected to monotonic and fatigue loading. In order to alleviate mesh dependency and capture fiber orientation dependent matrix cracking within a ply, a discrete crack (DC) model based on the phantom paired element is embedded into the continuum damage mechanics (CDM) framework. A crack will be inserted into an element if any one of the failure criteria (fiber tension and compression, matrix tension and compression, fiber-matrix shear) is reached. To be consistent with experimental observations, it is assumed that the crack direction is along the fiber direction within a particular ply. Both the energy dissipation and damage evolution are controlled by the CDM while the introduction of discrete cracks accurately captures the intensified local stress and strain fields in the cracked element. The modeling capability and solution fidelity of the CDDC methodology is demonstrated via the example of holed composite specimens subjected to static and fatigue loading.