Collapse mechanism and occupant injury analysis under vertical impact of the aircraft fuselage structure

This paper focuses on the crash response characteristics related to the collapse mechanism and occupant injury during a vertical drop test, which is crucial for evaluating the crashworthiness of fuselage section. A simplified three-frame typical large aircraft fuselage section is designed using the equivalent design methods for weight and moment of inertia, which including two sets of triple seats and four 50th-percentile FAA Hybrid III Anthropomorphic Test Devices (ATDs). A vertical drop test is conducted at a velocity of 6.02 m/s, and the collapse mechanism and occupant injury are analyzed. To evaluate the aircraft’s crashworthiness, a comprehensive evaluation is performed considering the survivable volume, retention strength, occupant injury and emergency evacuation, and the Integrated Crashworthiness Index (ICI) is also obtained by a scoring method. It has been proven that the failure position and failure sequence of fuselage structures affect the unrolling failure mode (three plastic hinges failure mode) and the flattening failure mode (multiple plastic hinges failure mode) of fuselage section, providing valuable insights into the crashworthiness design of aircraft fuselage section.