Multimodal Gaidai State-of-the-Art Limit Hypersurface Methodology for Container Vessels With Multiple Failure Modes

Abstract

This case study presents state-of-the-art, multimodal structural reliability and risk evaluation methodology, particularly suitable for naval architecture, transportation and marine engineering applications.

Existing reliability methods do not easily tackle systems with a number of critical components higher than 2, while the advocated multimodal reliability and risk evaluation methodology has no limitations on the system's number of dimensions, parts or components. The 4400 TEU container vessel's onboard measured deck panel stresses raw data, collected during numerous vessel's trans-Atlantic crossings, was analysed. Risk of ship hull and panel structural damage caused by excessive whipping (slamming and springing) wave loads, representing types of highly nonlinear wave-induced vibrations, are among primary safety concerns for the contemporary marine transportation industry. It is often challenging to accurately forecast excessive vessel's deck panel hot-spot stresses, possessing complex nonlinear, nonstationary properties. The proposed multimodal hypersurface reliability method fully accounts for a large number of structural components, as well as dynamic nonlinearities. Lab testing may often be disputed, as obtained measurements will depend on biased incident wave properties and model scales. As a result, the onboard dataset, obtained from a particular cargo ship, operating in the North Atlantic provides especially valuable insights into an overall dynamic vessel hull system's durability and reliability.

This investigation aimed at providing generic state-of-the-art reliability methodology, enabling accurate extraction of pertinent information about vessel hull system's dynamics, e.g., deck panel hot-spot stresses, derived from the onboard sensor-recorded time histories. Utilising proposed hypersurface reliability methodology, structural failure, hazard or damage risks may be effectively yet accurately forecasted, based on spatially distributed vessel deck panel stresses. The presented multimodal state-of-the-art reliability methodology may be particularly suitable for the evaluation of structural hazards of large dynamic systems, having virtually unlimited numbers of principal/key components. The presented study made use of the full scale onboard measured dataset, kindly provided by Det Norske Veritas, Oslo, Norway (DNV), which is commercially valuable on its own.