Effects of Pre‐Existing Crack Location and Orientation on the Aero‐Structural Response and High‐Stress Influence Zones of a Carbon/Glass Hybrid Composite Wind Turbine Blade

ABSTRACT

This study investigates the effects of crack location and orientation on the structural response and high‐stress influence zone (HSIZ) of a 1.5 MW carbon/glass hybrid composite wind turbine blade using laminate tensile tests, digital image correlation (DIC), computed tomography (CT), and one‐way aerodynamic–structural coupling analysis. Laminate tests revealed orientation‐dependent strain localization and damage paths. Although the mean peak load decreased from 8.1 to 5.2 kN as crack orientation increased from 0° to 45°, net‐section normalization showed that this trend was strongly influenced by the loss of effective load‐bearing area. At the blade scale, stress and equivalent elastic strain responses generally followed root > maximum‐chord region > tip and increased from 0° to 45° at both 12 and 20 m/s. The 45° root crack at 20 m/s produced the highest responses, reaching 68.64 MPa and 13.88 × 10 ⁻³ , respectively. Its HSIZ extended 435 mm toward the leading edge and 310 mm toward the trailing edge, indicating pronounced chordwise anisotropy and, for the investigated crack placement, a greater leading‐edge‐side influence. These findings support crack‐sensitive region identification, inspection planning, and structural health monitoring of composite wind turbine blades.