FIELD: aviation.
SUBSTANCE: invention relates to a collapsible, coiled mandrel for use in curing of a hollow carbon-epoxy structure, a method of manufacturing a collapsible, coiled mandrel. Stringer in aircraft construction is made of a fibre stiffened with doping material which maintains an outer coil shape resistant to external compression forces when used as a mandrel during lay-up and curing, and is collapsible when an end of the fibre is pulled along its longitudinal axis so that it can be easily removed after curing and discarded. Method of fabricating a collapsible, coiled mandrel employs a mould with a shaped recess for forming a coil with a fibre wetted with a doping material fed in by an applicator, with rotation of the applicator while backing it out to form the coil in the mould. In an alternative embodiment, a collapsible, coiled mandrel may be formed of a metal coil having a mandrel-shaped cross-section and sleeved in a protective liner.
EFFECT: invention improves physical and mechanical properties of products.
20 cl, 11 dwg
