ENERGY-RELEASE RATE DETERMINATION FOR EDGE DELAMINATION UNDER COMBINED INPLANE, BENDING AND HYGROTHERMAL LOADING .1. DELAMINATION AT A SINGLE INTERFACE

Edge delamination in composite laminates subjected to combined inplane, bending and hygrothermal loading is analyzed using a crack tip element approach. Classical laminated plate theory is utilized for the crack tip element formulation. Individual energy release rate components are found using a set of closed form equations derived from plate theory, plus the results from a single continuum analysis. For those cases where a linear elastic solution predicts a near-field oscillatory singularity, a new approach is used which allows a unique, physically meaningful value of fracture mode ratio to be defined.