Parametric studies on the impact response of offshore triceratops in ultra-deep waters

Abstract

This paper addresses the parametric studies on the impact response of offshore triceratops subjected to low-velocity impact. Triceratops is the object of the present impact study which is one of the new generation offshore complaint platforms with three buoyant legs connected to deck by ball joints. The innovative geometric form and compliant characteristics distinguish triceratops from conventional offshore platforms. The buoyant legs in triceratops are usually designed as orthogonally stiffened cylindrical shell structures. Numerical studies are carried out using Ansys Explicit analysis solver to predict the impact response and local damage of buoyant leg of triceratops. From the impact force time history obtained through explicit analysis, the hydrodynamic time response analysis is carried out in Ansys Aqwa to predict the response of deck and buoyant legs. Parametric studies are mainly focussed on the effect on the location of the indenter, size of the indenter, type of indenter, number of stiffeners and strain-rate definition. Force displacement curves are reported along with detailed numerical observations.