Numerical Assessment of the Structural Performance of a Segmented Wind Turbine Blade

Abstract

Segmented wind turbine blade (SWTB) development remains a major challenge for constructors so as to reduce blade transport and manufacturing costs. The blade structural properties must be examined in the design stage to enhance their mechanical behavior and fatigue life. This paper presents a numerical investigation of a SWTB prototype. Teeth inserted in holes at the interfaces of segments, were designed to avoid relative displacements between the segments assembled along a spar. Modal and fatigue analysis were established using ANSYS Workbench software to evaluate the structural performance of the investigated wind turbine blade (WTB). This work covers the impact of the assembly force and the rotation velocity effect on the blade fatigue life. Previous findings of an experimental study, of the SWTB at rest, were considered to validate the blade finite element model. To assess the used spar location, along the blade segments, the edgewise and flapwise deflections of the blade under assembly force effects were analysed. This study reveals the significant impact of the exerted assembly force on the SWTB fatigue life versus the rotation velocity effects. Interestingly, the obtained results indicate that a segments assembly force must be respected in the blade assembling to ensure the optimum service life.