Development of a Scale Model Composite Fuselage Concept for Improved Crashworthiness

A composite fuselage concept for light aircraft has been developed to provide improved crashworthiness. The fuselage consists of a relatively rigid upper section, or passenger cabin, including a stiff structural e oor and a frangible lower section that encloses the crash energy management structure. The crashworthy performance of the fuselage concept was evaluated through impact testing of a one-e fth-scale model fuselage section. The impact design requirement for the scale model fuselage is to achieve a 125- g average e oor-level acceleration for a 31ft/s vertical impact onto a rigid surface. The energy absorption behavior of two different sube oor cone gurations was determined through quasi-static crushing tests. For the dynamic evaluation, each sube oor cone guration was incorporated into a one-e fth-scale model fuselage section, which was dropped from a height of 15 ft to achieve a 31-ft/s vertical velocity at impact. The experimental data demonstrate that the fuselage section with a foam-block sube oor cone guration satise ed the impact design requirement. A second drop test was performed to evaluate the energy absorption performanceofthefuselageconceptfor an off-axis impactcondition. The experimental data are correlated with analytical predictions from a e nite element model developed using the nonlinear, explicit transient dynamic code MSC/DYTRAN.