Ocean Engineering, Volume 60, Pages 149-162, March 2013

Nonlinear Structural Consequence Analysis of FPSO Topside Blastwalls

Author(s): Jung Min Sohn, Sang Jin Kim, Byoung Hoon Kim and Jeom Kee Paik

Abstract:
Hydrocarbons can be exploded by ignition with the mixture of an oxidizer when the temperature is raised to the point where the molecules of hydrocarbons react spontaneously with an oxidizer. The hydrocarbon explosion causes a blast or a rapid increase in pressure. This kind of accidents causes serious casualties, property losses and marine pollution. Topsides of offshore platforms are most likely to be exposed to such hazards as hydrocarbon explosion and a number of major accidents involving them have been reported. The aim of the present study is to develop practical procedure for nonlinear structural response analysis of FPSO topside blast wall under explosion loads. Two methods are adopted for nonlinear structural consequence analysis of FPSO topside blast walls. One has been computed based on the use of time-domain nonlinear finite element analysis and another is performed with single degree of freedom method based on resistance function. The relationships between blast pressure versus impulse of FPSO topside blast walls are developed. This paper introduces the procedure of two methods and describes benefit of each method from the result comparisons. Insights modeling techniques and procedures of this study will be very useful and practical for explosion risk assessment of offshore structures.