Edge delamination in advanced laminated composites, theory and verification

Abstract

A damage evolution theory capable of predicting the effects of edge delamination phenomena on composite laminate response is developed. The theory is a mechanics-based formulation which quantifies the damage development of a laminate under general loading, and incorporates it directly to the constitutive behavior of the laminate. The theoretical development introduces a laminate-specific constant φ; the methodology of φ selection is presented for [±15/±50]s, [±45/0/90]s, and [0₂/90₂]s T300 graphite/epoxy laminates. Edge effects are demonstrated by comparing the damage state of the above laminates with and without edge delamination damage. The capability of the theory in predicting the volume scaling effect is shown through consideration of the failure strengths of the [±25/90n]s laminate series.