Experimental research on the compression failure of wind turbine blade trailing edge structure

ABSTRACT The wind turbine blade trailing edge (TE) is frequently exposed to compressive loading and can even be damaged under complex operating conditions. Among the most typical TE failure modes is the adhesive-joint failure, so it is necessary to evaluate the structural behavior of the adhesive joints in TE under compressive loading. In this regard, an improved testing method was proposed for blade subcomponents. Specifically, the experiment was performed on a composite TE structural specimen under compressive loading to reveal its internal failure mechanism. The results showed that when the TE specimen was compressed under increasing load, buckling deformation occurred gradually at the sandwich laminates. Also, the bending deformations of the laminates on the suction and pressure sides were different in the bonding region. The resultant shearing effect led to the structural adhesive undergoing brittle fracture, which then triggered debonding and extension, finally causing the debonding failure of the trailing-edge specimen. To guarantee the safety of a blade under edge-wise loading, it is suggested that the structural strength of the TE should be emphasized during the blade design process.