Evaluation of the Thermal Damage in Glass Fiber Polymer-Matrix Composites in Wind Turbine Blades Subjected to Lightning Strike

摘要

A primary motivation for this study comes from the need to improve the ability ofrnpolymer matrix composites to withstand lightning strikes. In particular, we arernconcerned with lightning strike damage in composite wind turbine blades. Thernproblem is essentially multiphysic, as the electric-current-induced temperature in therncomposite blade subjected to a lightning strike may reach up to 1,200 ℃, leading tornextensive thermal damage including surface damage, delamination, cracks, matrixrndecomposition, fiber breakage and sublimation, and abrupt failure of the blade.rnIn this work, the thermal response of the polymer-matrix composite laminate usedrnin a Sandia 100-meter All-glass Baseline Wind Turbine Blade (SNL 100-00) subjectedrnto lightning strike is studied. The tip region composite panel is considered, as it hasrnbeen reported in the literature that the blade tip is more susceptible to lightning strike than the remaining parts of the blade.rnA physical model to show the surface interaction between the lightning arc and therncomposite structure has been developed. The model provides time- and electriccurrent-rndependent variation of the lightning arc radius and lightning-current-inducedrnheat flux generated at the composite surface. The temperature-dependent thermalrnproperties of the VectorPly E-LT 5500 unidirectional [0]_2 E-glass fiber vinyl esterrnresin matrix fabric and SNL triaxial [±45]_2[0]_2 E-glass fiber vinyl ester resin matrixrnfabric used in the wind blade tip composite panel were derived using availablernexperimental data. The formulated nonlinear transient heat transfer problem withrnmoving boundary is solved using the finite element method. The solution procedurernaccounts for phase transitions in the materials, and the obtained results includerntemperature field profiles and evolution of the thermal damage.