A system includes a turbomachine blade segment including an airfoil with an exterior surface, and a platform coupled to the airfoil having a first side and a second side. The system also includes a concave fillet transition extending between the airfoil and the platform. The concave fillet transition includes one or more interface ply segments extending across the exterior surface of the airfoil and the first or the second side of the platform to form a continuous surface between the airfoil and the platform.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH & DEVELOPMENT
 This invention was made with Government support under grant number DE-FC26-05NT42643-ARRA awarded by the Department of Energy. The Government has certain rights in the invention.