Modelling and Synthesis of High Speed Craft Acceleration Profiles

High Speed Craft (HSC) occupants are subjected to a harsh environment characterized by vibration and repeated shock. Significant research has therefore been invested into HSC shock mitigation. The objective of this work was to determine standard shock acceleration profiles for HSC based on sea trial data. The knowledge of real-life sea inputs is important for in-lab testing of HSC shock mitigation seats. Sea trial vertical acceleration data of a Rigid-Hull Inflatable Boat was analyzed with the aim of characterizing shock acceleration pulses experienced by the boat. Five common types of shock acceleration profiles were identified. These profiles were represented by a combination of modified Gaussian curves. The statistical characteristics of the observed pulses were obtained by curve fitting the data. An algorithm employing copulas and non-parametric density estimation was developed for generating synthetic time histories which have the same statistical characteristics as the observed data.