ABSTRACT
Most of the composite materials are used in the form of laminates consisting of a continuous matrix with different fiber orientations. The microcracking in the elastic medium has been identified as the major damage-causing mechanism in brittle materials. The growth and coalescence of microcracks are usually incorporated into a damage matrix of brittle and quasi-brittle solids. Disorder microcracks in brittle or quasi-disorder is the cause for many deformation and fracture mechanics. Matrix cracks may lead to other damage such as delamination and fiber breakage in laminated composite materials. Most of numerical theories are based on continuum approaches and the multiply crack condition of the continuum damage is not enough to predict the failure. The major remaining problems were attributed as sensitivity of the materials to complex loading and mechanics of crack formation and development of secondary cracks into consideration of modelling.
