Jet Engine Fan Blade Containment using Two Alternate Geometries

Kelly Carney, Mike Pereira, Duane Revilock, and Paul Matheny In the rare event of a fan blade separation, the fan blade must not penetrate the case of a commercial jet engine. Due to this requirement the fan case is the heaviest single component of a jet engine. With a goal of reducing that weight, a simulation of a fan blade containment system was tested at the NASA GRC Ballistic Impact Lab and analyzed using LS-DYNA. A fan blade simulating projectile was shot at two alternate geometric containment case configurations. The first configuration was a flat plate which represents a standard case configuration. The second configuration had a surface curved outward from the projectile. The curved surfaced forces the blade to deform plastically, dissipating energy before the full impact of the blade is received by the plate. The curved case was thus able to tolerate a higher velocity of impact before failure. The LS-DYNA analytical model was correlated to the tests and a weight savings assessment was performed.