A three-dimensional progressive damage model has been developed to capture the onset and initial propagation of damage within a three-dimensional woven composite in a single-bolt, double-shear joint. Reinforced with a three-dimensional woven ply to ply interlock IM7 carbon fiber preform impregnated with toughened epoxy resin and manufactured using a resin transfer molding process, the composite represents a unique material currently used in select aerospace structures. The modeled joint is commonly found in many aerospace structures and, when combined with the progressive damage response of this three-dimensional woven composite, the material response can be reliably predicted with a three-dimensional non-linear finite element model. This model is constructed using an orthotropic material assumption far from the bearing area and a voxelized mesoscale model with an as-molded geometry representing matrix and impregnated tow phases. The well-established Hashin failure criteria and the Matzenmiller–Lubliner–Taylor damage model were implemented with the unique morphology of three-dimensional woven composites. The onset of damage and trends seen in the model were found to be in agreement with previous experimental findings

A formal engineering approach of the mechanics of thin-walled laminated beams based on kinematic assumptions consistent with Timoshenko beam theory is pre sented. Thin-walled composite beams with open or closed cross section subjected to bend ing and axial load are considered. A variational formulation is employed to obtain a com prehensive description of the structural response. Beam stiffness coefficients, which account for the cross section geometry and for the material anisotropy, are obtained. An explicit expression for the static shear correction factor of thin-walled composite beams is derived from energy equivalence. A numerical example involving a laminated I-beam is used to demonstrate the capability of the model for predicting displacements and ply stresses.