A Simple Method for Calculating Energy Release Rates due to Free-Edge Delamination in Laminates

Abstract

A new, simple method for calculating strain energy release rates due to delamination propagating from free edges of composite laminates under uniform axial extension is presented. Saturated values associated with the delamination growths are given by the use of classical lamination plate theory and the J-integral. Numerical example shows good agreement with the finite element analysis. The method is extended to calculate energy release rate due to delamination around holes. Free edge delamination under pure bending is also considered and the calculated values are compared with those from finite element analysis. Owing to the simplicity, the present method is suitable for preliminary design analysis, which requires a lot of configurations to be examined.