Elasto-Plastic Beam Afloat on Water Subjected to Waves

Abstract

This paper addresses development of a mathematical model which describes the behavior of an elasto-plastic beam afloat on water surface. The mathematical model is valid for predicting the collapse of a Very Large Floating Structure (VLFS) subjected to extreme wave-induced vertical bending moment. It is a follow-up of the previous work in which the collapse behavior of a VLFS is pursued by adopting a segmented beam approach. In this research, the whole VLFS is modelled with elasto-plastic beam elements. The hydrodynamic behavior is modeled by using Rankine source panel method based on time-domain potential theory. It is shown that the elasto-plastic beam approach gives almost the same result as the segmented beam approach for predicting the one-element collapse behavior. The elastoplastic beam approach is extensively used to predict the progressive collapse spread over multiple sections, which cannot be followed by the segmented beam approach.