Failure analysis at trailing edge of a wind turbine blade through subcomponent test

Abstract

This paper presents an in-depth analysis of the failure mechanism for the blade trailing edge from the viewpoint of material damage. A 3 m long blade segment is made and subjected to the static load in the subcomponent test through a specially designed test rig. A finite element model is set up to predict the progressive failure in the trailing edge region. The simulation results are used for setting up the on-site test and further, compared with the test results. The initial damage location and evolution of each defect are elucidated by cutting the test subcomponent into slices. The damage details of the test subcomponent and sensors data show that the end force leads to the local buckling of the PS and SS surface near the blade tip side. The buckling induces the damage to trailing edge materials, especially the sandwich structure in SS, and further bonding failure of the adhesive joint, which reduces the global strength of the subcomponent structure. The fracture of the sandwich caused by continued pressure leads to the final collapse of the test subcomponent.