Composite Wind Turbine Blade Effects of Defects: Part B— Progressive Damage Modeling of Fiberglass/Epoxy Laminates with Manufacturing Induced Flaws

*† ‡ § The Effects of Defects is important for the reliability of modern composite wind turbine blades. The DOE has sponsored a comprehensive study to characterize common manufacturing defects and establish damage growth and validation tools to contribute to a wind turbine blade reliability infrastructure. To support this development of a reliability infrastructure, progressive damage modeling of blade representative coupons has been performed. Initial modeling efforts have been established and correlated to existing experimental results. Two types of analytical models have been investigated and developed with larger scale testing and analytical correlation in mind. A progressive damage routine utilizing combined maximum stress/maximum strain failure criteria was implemented allowing for different types of damage to be estimated. The material properties for damaged elements were then degraded for the appropriate damage mode and type. Two-dimensional (2D), four-layer coupon level models were utilized in increasing complexity from Controls to a flawed specimen containing an In-Plane Wave. Initial models were used to develop convergence in compression and tension before developing a model for an In-Plane Wave group. The results indicate that reasonable correlation was achieved between all groups and their respective experimental data. While some minor discrepancies exist, it appears that they will be an initial point for modeling of larger scale coupons or subsections.