Localization and Evaluation of Fatigue Damage in Long Fiber Epoxy Laminates with Measurements Based on Image Correlation

A study on fatigue damage characterization for long fibre epoxy composites is here presented. The main aim is to calculate with full field technique the local damage experimental parameters, in order to express the material damage state and to validate a procedure for the localization of the probable zones of failure. It is well known that fatigue damage evolves mainly in some localized areas and it is important to monitor these points throughout the residual life. Two damage parameters are chosen as representative for failure evolution: local stiffness reduction and dissipated energy per cycle. These parameters are cyclically evaluated on the base of deformation monitoring, by the means of Digital Image Correlation technique. Full field measures are stored and elaborations allows to distinguish the most damaged zones.