Strength prediction of woven hybrid composite laminates each with a center hole

In this study, the notched strengths of woven hybrid composite laminates each with a center circular hole were investigated. The effective engineering moduli of the composite laminate were first predicted by the spring model method and the stiffness averaging method. Then, a finite element-based point stress criterion proposed previously by the authors was employed to predict the notched strengths of those woven hybrid composite laminates each with a center circular hole. It is shown that the predicted notched strengths by this approach agree well with the experimental results. It is also noted that the notched strength decreases with the radius of the center circular holes for both the drilling and water jet cases. However, the decreasing rate of the notched strength for water jet is obviously higher than those for drilling.