Dynamics of and injury assessment to occupants in high-speed planing boats under pure vertical loading condition using a human body model with active muscle behavior

Abstract

In the maritime industry, with special emphasis on military and rescue operations, often situations arise where a rapid response is required. During these periods, the use of high-speed planing crafts is of utmost importance, due to their ability to address the situation in a quick manner and with great maneuverability. Although the employment of these crafts is a common practice in the naval industry, studies have shown compelling evidence of potential significant injury risk for high-speed boat operators due to the repeated shock impacts of the craft against the sea. The injuries related to these impacts have been identified as both acute and chronic, reducing both the short-term and long-term effectiveness of the personnel exposed to it. This study is aimed at addressing the safety of high-speed crafts occupants when exposed to pure vertical loading conditions by using a numerical human body model to simulate the response of humans under typical high-speed planing boat impacts. In order to achieve that, a representative run-time efficient multibody model of a pure vertical one-wave impact scenario is developed, validated, and utilized. Multibody techniques to model the structural systems and Madymo’s active human body model are employed to represent and evaluate the potential injury to the boat occupants. Additionally, a parametric study is conducted to assess the influence of identified parameters to the injury severity on high-speed craft occupants. The parametric study yields one scenario with a significant lumbar load reduction, where armrests and hand holders are added to the seat structure. The importance of the active muscle behavior to the injury assessment process is demonstrated by comparing the results of the reference model with muscles in active and passive modes.