Crash Simulation of an Unmodified Lear Fan Fuselage Section Vertical Drop Test

The nonlinear explicit dynamic finite element code, MSC/DYTRAN, was used to simulate a 31 ft/s vertical drop test of a composite Lear Fan 2100 aircraft fuselage section, which was performed at the Impact Dynamics Research Facility of NASA Langley Research Center. The Lear Fan fuselage section is fabricated of graphite-epoxy fabric material and is approximately 60 in. in diameter and 11 in. in length. The fuselage section consists of a composite skin with two C-frame stiffeners. The subfloor contains four aluminum keel beams, which are supported vertically and laterally with composite stanchions. Two aluminum stools, each loaded with 100 lbs. of lead mass, were mounted to the section to simulate the inertia provided by a seat and occupant. The objective of the crash analysis was to evaluate the capabilities of the MSC/DYTRAN code in predicting the response of composite airframe structural components subjected to impact loading. Correlation of the analytical results with experimental acceleration, velocity, and displacement time histories indicated good agreement. However, the success of the correlation was found to be highly dependent on correctly predicting the failure mode of the composite stanchions.