A Comparison of Two-Dimensional and Three-Dimensional Hydroelasticity Theories Including the Effect of Slamming

Abstract

The behaviour of slender and non-slender flexible bodies travelling in irregular seaways is examined. This is achieved by using a two-dimensional (2D) and a three-dimensional (3D) theory. These theories are based on different assumptions and mathematical models, though both are capable of assessing the influence of transient loadings caused by slamming. The two-dimensional theory is restricted to steady state and transient vertical responses (motion, distortion, bending moment, shear force) in irregular head waves, whereas the three-dimensional theory allows calculations of both vertical responses and transverse responses (motion, distortion, bending moment, shear force, twist) in head and oblique waves. Time-domain simulations of the responses (steady state and transient) are generated from which statistical data are determined. For a slender uniform barge structure travelling in head seas, the response simulations and statistical data evaluated by the two theories show favourable agreement. However, for a non-slender uniform barge differences between predictions arise with the two-dimensional strip theory eventually failing, while the three-dimensional approach remains effective and its versatility is further demonstrated by predicting the slamming behaviour of a flexible barge structure travelling at arbitrary heading in an irregular seaway.