Method of making a hollow airfoil

摘要

A method of making hollow aircraft rotor blades from laminated material. An expandable mandrel is first made from curable materials and then a composite build-up of epoxy material is made by layering a plurality of prepreg plies of curable material over the expandable mandrel. The mandrel and build-up of epoxy materials are then placed in a mold and pressure is applied to expand the mandrel which, in turn, expands the build-up of material against the mold. The mandrel and composite build-up of material are then cured and the mandrel becomes an integral part of the rotor blade.