Damage Analysis in Fiber Composite Sheets and Uncoated Woven Fabrics

The mechanics of damage of fiber composite sheets has been reviewed, including cases where the analytical models have been compared to experiments. The emphasis has been on the micromechanics approach, where equilibrium of the constituents of the composite lead to appropriate equations for determining stress distributions. The damage mechanisms that have been treated include fiber breaks, matrix cracking (splitting), and debonding at the fiber/matrix interface. Effects of matrix yielding, hybrid composites, the hybrid effect, and thermal response have also been discussed. The usefulness of the shear lag model (SLM) in both stress and fracture considerations is clearly exhibited by the results in the literature. Work on damage growth in uncoated woven fabrics has also been reviewed, together with its importance in Army applications. In the study of the localized mechanics of woven fabrics near damage sites (eg, yarn breaks), the important deformation mechanisms include crimp interchange between yarns, yarn slipping, and yarn rotation. Growth of slit-like damage as a progression of yarn breaks is reviewed. The structure of the equations in the analytical models is similar to the SLM, and a parameter appears which can be used to compare fabrics as to their damage tolerance. This review article includes 117 references.