Fan case design with metal foam between Kevlar

Abstract

A fan blade fragment containment assembly for a gas turbine engine having a fan case surrounding the fan and having a circumferential axially extending blade fragment impact zone. An inner relatively slack or low tension deformable layer of Kevlar™ or Zylon™ fabric is mounted to the fan case outer surface and envelopes the impact zone. A compressible (ex. metal foam or honeycomb) layer is mounted on an outer surface of the deformable layer. A friction reduction layer of Teflon™ is mounted on an outer surface of the compressible layer and an outer relatively taut higher tension containment layer of Kevlar™ or Zylon™ fabric is mounted on an outer surface of the friction reduction layer. The friction reduction layer enhances the distribution of impact forces about the circumference of the compressible layer by reducing local shear stresses between the compressible layer and the containment layer.

Dependencies are inferred from the claim text.