A Discrete Crack Network Based Damage Assessment for Bolted Composite Structures

The failure prediction of a bolted joint is complex due to the presence of contact, plastic deformation in the fastener, hole wearing, hole edge crushing, and micro-buckling near the compressive loading zone. In order to capture the mechanism-based failure modes associated with matrix cracking, delamination, fiber breakage, and crushing under a bearing and clamping load, a continuum damage and discrete crack (CDDC) solution module for the Abaqus toolkit is developed where the continuum damage is used to control the damage evolution and energy dissipation and the discrete crack model is used to accurately describe the intensified local stress and strain fields for the subsequent damage evolution prediction. High fidelity discrete damage modeling is demonstrated for a bolted composite lap joint under a static tensile loading. Comparative studies using the continuum damage model (CDM) and CDDC are performed for a filled hole specimen under cyclic tensile loading.