Self-heating forecasting for thick laminates testing coupons in fatigue

Thick laminate sections can be found from the tip to the root in most common wind turbine blade designs. Obtaining accurate and reliable design data for thick laminates is subject of investigations. Due to the poor thermal conductivity properties of composites and the material self-heating that occurs during the fatigue loading, high temperature gradients may appear through the laminate thickness. In the case of thick laminates in high loads regimes, the centre section temperature might exceed the material operational range, leading to premature failures. In the present work a method to forecast the self-heating of thick laminates in fatigue loading is presented. The mechanical loading is related with the laminate self-heating, via the cyclic energy strain and the energy loss ratio. Based on this internal volumetric heat load a thermal model is built and solved the get the temperature distribution in the transient state. Based on experimental measurements of the energy loss factor for 10mm coupons, the method is described and the resulting predictions are compared with experimental surface temperature measurements on 10 and 30mm UD thick laminate specimens.Aerospace Engineerin