Damage in composite laminates with off-axis plies - Texas A&M University (TAMU) Scholar

Damage in off-axis plies of composite laminates is studied by examining the configuration [0/ 4/0( 1/2 )](s) with =25, 40, 55, 70 and 90 subjected to tensile loading in the axial direction. It is found that for the values of , where the stress in the off-axis plies normal to the fibers is tensile, ply cracks lying along fibers initiate and increase in number, while for other values the plies do not undergo this damage, as expected. However, the overall laminate elastic moduli are also found to change for the values where no ply cracks exist. It is postulated that a shear-induced degradation of the off-axis plies is responsible for the observed laminate moduli changes. The prediction of changes in these moduli by using the ply shear modulus measured on [4](s) appears to support this postulate. For the case of moduli changes caused by ply cracks the recently proposed synergistic damage-mechanics approach [1] is applied. The implications of the findings of this work on a class of continuum damage-mechanics formulations proposed in the literature are discussed.

Damage in composite laminates with off-axis plies Academic Article