An inverse approach for load identification of cracked wind turbine components

Abstract

ABSTRACT To assess the integrity of a structure, it is necessary to be familiar with the applied loads on its components. In this paper, an inverse modeling procedure was developed to identify the unknown static loads of a cracked component made from a brittle material, using a recently developed phase-field fracture modeling approach. The main goal was to define the optimal number, position, and orientation of the strain gauges on the structural component needed to accurately determine the imposed loads leading to different crack sizes and crack orientations. This enables an accurate assessment of the structural integrity of the components throughout their entire service life, including the process of crack initiation and its stable growth to a critical length. To verify the inverse approach, several numerical benchmark examples as well as the vital components of the wind turbine, such as the axle pin were analyzed. It is shown that the proposed approach with optimally placed strain gauges enables the accurate estimation of complex loads in a fractured component.