Implementation of a Drop Test Impact Rig for Dynamic Testing of High Speed Craft Shock Mitigation Seats and Extraction of Modal Parameters

Abstract

The high-g loads occurring at the seat-deck interface locations during slam impacts experienced on high-speed crafts in moderate to high seas results in serious potential for injury to the occupants. The need for a standard testing platform and experimental analysis to investigate a seat's effectiveness forms the major objective of research being carried out by Carleton University's Applied Dynamics Laboratory (ADL) in partnership with Defence Research and Development Canada-Atlantic (DRDC-Atlantic). A drop tower was designed and manufactured by the ADL for testing seats in order to characterize their shock mitigating effectiveness by simulating the severe conditions of a slam impact at sea through the use of singular impact testing. Further, in order to identify the seats' dynamic parameters from drop test data, the Eigensystem Realization Algorithm (ERA), a modal-analysis-based system identification method, was applied to two commercial shock-mitigating seats provided by DRDC-Atlantic.