Failure Criterion‐Based Bead Optimization of a Wind Turbine Blade Root Section

ABSTRACT This study presents a bead‐based optimization framework for fiber composite wind turbine blades, employing the Tsai–Wu failure criterion as the structural performance measure. The objective is to design an optimal transition geometry between an existing blade and a root section with 20% smaller diameter, while preserving the original material layup and shell thickness. The optimization aims to minimize the Tsai–Wu failure index while maintaining or improving stiffness properties. The proposed approach integrates the Tosca structure with a user‐defined subroutine implementing the Tsai–Wu criterion. Because the current outer blade surface is not parameterized, a general bead optimization procedure is applied, where nodal positions of shell elements in the finite element model are adjusted to achieve an optimized root geometry. The results demonstrate that bead optimization effectively produces a smooth transition region, reducing the Tsai–Wu failure index without altering the global aerodynamic shape and offering a practical solution for industrial applications where mold reuse and manufacturing constraints are critical.