The SNL/MSU/DOE Fatigue of Composite Materials Database: Recent Trends

Abstract

Trends of recent test data in three areas are described for wind blade materials in the SNL/MSU/DOE fatigue of composite materials database 1 . First, a complete 3-D set of static elastic constants and strength properties is given for a thick infused glass fabric/epoxy laminate. Second, results are presented which explore the effects of fabric structure and resin type on the tensile fatigue resistance. Using aligned strand structure as a baseline, the efficiency of stitched fabric reinforcement is quantified for static and fatigue properties, and the origins of poor fatigue performance with some resins are identified. Third, an overall comparison is given of the tensile fatigue sensitivity of various blade materials including laminate in-plane and interlaminar failure, epoxy based blade adhesives and core materials. Comparisons of fiber dominated and resin dominated failure modes show clear trends in the fatigue exponent, depending on the resin system.