Containment Ability of Kevlar 49 Composite Case under Spinning Impact

Abstract

The Kevlar 49 composite material (DuPont, Wilmington, Delaware), which is of light weight and high strength, is used increasingly as a containment structure for fan blades. This paper proposes a spinning impact testing method to investigate the containment ability of Kevlar 49 composite case after fan-blade-out (FBO) events. Three spinning impact tests are conducted to closely simulate actual FBO events by considering the impact angle and blade rotating factors. These tests show three distinct results: contained, critical contained, and uncontained. The computational model is developed and correlated with the experiments. It shows that eight layers of Kevlar fabric can succeed in catching a released blade with 4, J energy under spinning status, of which 3,83 J is absorbed by the Kevlar fabric. A comparison with the data published in the Federal Aviation Administration reports indicates that Kevlar 49 composites have greater containment potential under a spinning impact. A different containment mechanism is found in which a bulge is formed in the radial direction of the fabric, flowing along the circumference together with the rotating blade when the contact zone is expanded. This mechanism should be considered when applying woven fabric to an aero-engine containment system.