Strength prediction of the notched composite laminates from equivalent un-notched laminates

Abstract

In this paper, a theoretical failure model is proposed to predict ultimate strength of fiber-reinforced composite laminate with a circular hole. In the failure model, the laminate with a circular hole is modeled by an equivalent intact laminate which contains laminae with the same stacking sequence but with equivalent stiffness and strength derived by micromechanics and point stress formulation, respectively. The ultimate strength of this equivalent intact laminate is calculated by the improved Puck’s failure theory combined with stiffness degradation model. The failure model so formulated is applied to notched laminates with arbitrary stacking sequences. The capability is demonstrated by strength predictions of several multidirectional notched laminates, including [45∘/0∘/−45∘/90∘]2s AS4/3501-6 notched laminates, [45∘/90∘/−45∘/0∘]4s IM7/8552 notched laminates and [0∘/902∘/0∘]4s AS4/3502 cross-ply notched laminates, which are in good agreement with experimental results.