Dry preform, annular structure made of a composite material, and manufacturing method for the annular structure

摘要

Provided is a first reinforcing fiber layer (11) formed of reinforcing fibers which are wound around an outer periphery of a mandrel (20), aligned in parallel to a direction (+¸ direction) in which the reinforcing fibers intersect with an annular direction (0° direction) of the mandrel (20), and seamlessly continue in the annular direction of the mandrel (20) by an amount of at least one rotation.