Effects of Defects: Part A - Development of a Protocol for Defect Risk Management & Improved Reliability of Composite Structures

The Effects of Defects in composites materials common to wind turbine blades is presented in this work. A comprehensive approach has been taken by the authors for the development of a wind turbine blade reliability infrastructure. The framework for a defect risk management and composite structure reliability protocol has been developed. Specific applications to wind turbine blades are discussed. However, the approach has broader implications to composite structures in general. This framework consists of four interrelated, yet distinct efforts: 1.) Effects of Defects which are focused on characterization of flaws physically and mechanically. 2.) Probabilistic Modeling which asses the probability of failure while taking in account variables at all levels of the structure. 3.) Criticality Assessment is used for evaluating the risk of operating an as built flawed structured. 4.) In-Field Evaluations provide feedback and validation. This general framework is described herein along with the data generated to date in support of an application. Testing and analysis on a specific material system are presented but are applicable to other materials and structures.