Strength Prediction of Non-Conventional Laminates by Incorporating Intralaminar Shear Stresses

Abstract

A quasi-isotropic laminate, a laminate of which the in-plane stiffness matrix is independent of the laminate orientation, similar to a metal, can be achieved in multiple ways. One method is to create a laminate with layers orientated at conventional angles, such as 0, 90, 45, and -45. Another method is to use layers orientated at angle different than the aforementioned; using non-conventional orientation angle of 15, -15, 30, -30, 60, and -60. For the sake of clarity, the former (a laminate with only 0, 90, 45, -45 degree plies) is referred to as a ‘conventional’ laminate, while the latter (a laminate with ply orientations other than only 0, 90, 45, -45 degree plies) is referred to ‘non-conventional’ laminate in this investigation. It is important to note that a laminate consisting of conventional angle can have a non-conventional stacking sequence (the order of which the layers are stacked), however, the term conventional and non-conventional are reserved to the angles only.