Damage Mechanics and Fatigue Life Assessment of Composite Materials

The present state of fatigue life assessment of composite materials is largely empirical. This paper discusses how the discipline of damage mechanics can elevate this status to a mechanisms-based methodology. Specific topics addressed are mechanisms of fatigue damage, ehaTacteri7.ation of damage and its evolution, criticality of damage and prediction of fatigue life. Data and analysis results for cross ply laminates are used to illustrate and discuss the topics.