Composite Turbine Airfoil Structure for Low Weight and High Strength

The patent employs a multi-layer composite structure consisting of a foam core, fabric layers, and resin coating. This composite construction combines materials with complementary properties: the foam core provides lightweight structural support, the fabric layers add tensile strength and dimensional stability, and the resin coating provides surface protection and bonding. This layered composite approach enables the airfoil to achieve reduced weight while maintaining or enhancing structural integrity in high-temperature turbine engine environments.

The patent employs preliminary action by pre-impregnating the fabric layers with resin (prepreg technique) before assembly. This allows the fabric to be cut and shaped to the complex airfoil geometry in advance, with the resin already in position to provide bonding and structural properties. The foam core is also pre-shaped to match the desired airfoil cross-section. This preliminary preparation simplifies the final assembly process while enabling complex three-dimensional shapes that would be difficult to achieve with traditional manufacturing methods.

The patent applies local quality by varying the thickness, material composition, and orientation of the fabric layers and foam core density at different locations within the airfoil structure. For example, the foam core may have varying cell density to provide enhanced strength in high-stress regions while maintaining lightweight properties in lower-stress areas. The fabric layers can be oriented at different angles and with different weights depending on the local stress requirements. This localized optimization allows the structure to achieve maximum strength where needed while minimizing overall complexity and weight.