Damage prediction hybrid procedure for FRP laminates subjected to random loads

In this paper, a hybrid procedure is formulated in order to predict the damage of a laminate composed of UD FRP laminae under random loading. This procedure is based on two pillars: a stiffness degradation model (SDM) combined with an energy approach taking into account the effect of load ratio in addition to a system of equations generated by SSDQM (space state differential quadrature method), which we solved with a novel technique. The outputs of SSDQM, previously used for free vibration behavior analysis of composite structures, are used with those of SDM to predict the damage failure of a composite laminate subjected to random loading. The obtained results correlate very well with the experimental ones and an extensive comparison with other models validate the accuracy and convergence characteristics of this hybrid procedure.