Session: 06-12-01 Ship Hydromechanics I

Paper Number: 78713

78713 - A Reliable Multilevel Method for Simulation-Based Load Determination on Deck Cell Guides 

n the recent past, several accidents have led to the loss of containers at sea, causing endangering for ships and crew as well as environmental pollution. Within the Joint Research Project RetroLadung, weight-optimized container cell guides with integrated motion sensors and AI-based decision support (DSS) are developed as a technical solution for increased safety in marine transportation.

Therefore, the authors developed an efficient multi-level approach to determine the motion-induced loads acting on the containers. In a first step, the motion responses in irregular waves are determined with computational efficient boundary element methods in frequency domain. The wave parameters as well as the loading and operational conditions are selected according to the operational profile and travel route of the vessel. Then, in situations where large motion amplitudes are expected, time domain simulations are used to evaluate the dynamic behavior of the vessel. This allows the inclusion of important non-linear effects, like roll damping and viscous drag. For the validation of the applied numerical methods, extensive model tests have been performed in the towing tank operated by the Institute for Fluid Dynamics and Ship Theory (FDS). Comparisons between experimental and numerical results show good agreement of the vessel motion in regular and irregular waves. In a second step, maximum loads for ultimate strength analysis are derived from the simulation results and included in the weight-optimization process of cell guide structures. In a third step, reliable loads for fatigue analyses are determined, which will be added to the structural optimization process. The results of the developed load determination method are compared with the recommendations from classification societies to identify possible optimization potential.

The paper presents the development of the multi-level method, results from the ongoing experimental validation work and its implementation into to the weight-optimization process of the cell guide structures. Finally, the application of the developed method is demonstrated by calculating the loads for the structural optimization of the cell guides for a towed container barge operated at the US east coast.

Presenting Author: Ole Detlefsen Hamburg University of Technology

Authors:

Ole Detlefsen Hamburg University of Technology
Carl Reiner Hamburg University of Technology
Moustafa Abdel-Maksoud Hamburg University of Technology