Wind turbines play an important role in harvesting alternative sources of energy. The turbine blade is the critical component in a wind turbine. An optimal blade design is crucial to the ultimate efficiency and strength of the turbine.

For their excellent formability and density to strength ratios, fiber-reinforced composite materials are now extensively used in the blade construction. Compared to their conventional counterparts, composite materials introduce a number of additional design parameters, such as the matrix and fiber material properties, laminar thicknesses, and fiber orientations.

Each blade design must be carefully verified. For example, to avoid a catastrophic failure, a design must not lead to a natural frequency close to any of the resonance frequencies. Without the aid of an effective simulation tool for design verification, the design process of a composite blade can be excessively time-consuming.

Because of the complex blade geometry, a typical strategy is to create a 3D finite-element model of the turbine blade using shell or solid elements. With a detailed 3D model, both global and local mechanical responses of the blade can be adequately predicted with shell or solid elements. The disadvantage of using shells or solids becomes apparent when design changes are necessary.

A small variation in the design can lead to partial or even complete reconstruction of the 3D model. Because 3D models are generally difficult to build and modify, frequent modifications during the design process may be impractical.

In some circumstances, especially during the preliminary design stage, only the global mechanical responses of the blade are sought. A simplified model, such as a 1D beam model, is more desirable for such situations. Beam elements with advanced section-modeling capabilities can be used to accurately predict natural frequencies of a typical composite turbine blade with minimal modeling effort and computational costs.