Simulation research on influence of civil aircraft sub-floor structural parameters to fuselage crashworthiness and optimization based on crashworthiness

For ensuring occupant's survivability in case of survivable crash accidents, civil aircraft should have good crashworthiness. The key part of civil aircraft fuselage crashworthiness design is sub-floor structures including sub-floor frames, structures under luggage cabin and luggage cabin struts. A typical civil aircraft fuselage was simplified and a 1/4-scale dynamics simulation model based on the simplified structure was built with LS-DYNA3D, a nonlinear dynamics analysis code. With the scale simulation model, the influence of the strut location, strut slope angle and the luggage cabin height to drop and crash properties of aircraft was investigated. For better crashworthiness, the civil aircraft fuselage sub- floor structural parameters were optimized based on Kriging model built from samples determined according to Uniform Experimental Design (UED), which could decrease computation cost greatly. The results show that appropriate values of these structural parameters can improve the crashworthiness of civil aircraft fuselage structures effectively.