Prediction and evaluation of working conditions on high-speed craft using suspension seat modelling

Abstract

Severe working conditions on board high-speed craft adversely affect not only the safety, health and performance of the crew but also the performance of the vessel as a technical system. Human factors-based ship design combined with appropriate vibration mitigation techniques and work routines for the crew can improve the working conditions and reduce the risks for performance degradation and adverse health effects. To enable development and use of such means, methods for prediction and evaluation of working conditions are needed for both existing high-speed craft and craft under design. This article presents a 2-degree-of-freedom seat model compatible with both measured and simulated input data. The interaction between seat and human is treated using the concept of apparent mass. The model is validated against experiment data collected on board a 10-m, 50-knot high-speed craft equipped with high-standard suspension seats. Evaluation measures defined in ISO 2631-1 and ISO 2631-5 are used to compare experiment data to modelled data. The seat model slightly overestimates the experiment S ed dose by a mean of 6.5% and underestimates the experiment vibration dose value (8 h) by 4.0%. It is concluded that model data correlate well with experiment data.

Safety Improvements for High-Speed Planing Craft Occupants: A Systematic Review

“…Mathematical modeling is a reliable approach for predicting shock-mitigation seat performance in mitigating repeated continual vibrations and impact shocks. The studies by Olausson and Garme [108] and Marshall and Riley [96] have compared mathematical results with both sea trials and drop-tower tests, confirming the acceptable accuracy of the models. Other researchers have also conducted sea trial tests on shock-mitigation seats to verify mathematical models against real sea states [87,104,109].…”

“…Following the introduction of model B1, Alam et al [95], Townsend et al [16], Ereq [109], and Ekstrom [86] used model B2 to predict seat performance in absorbing slam impacts. Additionally, model B2 was applied by other researchers to study HSPCs in different sea states [84,86,108,109,117,118]. In previous research, seat model B2 garnered more interest among researchers compared to model B1.…”

Hyperloop – prediction of social and physiological costs

“…Some of the measures presented a gradual increase of tension and sympathetic nervous system activity with every increase of speed (0 km/h, 30 km/h, 90 km/h and 120 km/h), while some only changed with the higher speed levels (90 km/h and 120 km/h) [18]. The military personnel using high-speed boats (40 knots) was repeatedly reported to have decreased cognitive and physical performance just after the transit [19,20]; however, it was partially explained by shocks and vibration [21], which could be eliminated in the Hyperloop trains.…”

Extreme events and their optimal mitigation in nonlinear structural systems excited by stochastic loads: Application to ocean engineering systems

“…In figure 1 we illustrate the first model consisting of a linear primary structure under base excitation that is attached to a small oscillator connected through a nonlinear spring (with cubic nonlineariry). This is a prototype system modeling the suspended seat of a high speed craft [25,5]. The vibration absorber is attached to the seat with the aim to minimize ocean wave impacts on the operator of the vehicle and naturally we require that the attachment mass is much lower than the seat mass (i.e.…”