Mechanic Analysis Of Jacket Platform And Corrosion Damage Evaluation

Ocean offshore platform plays an important part of Offshore oil development process,which has long been the wind, wave and current environmental loads, because of salt mist,humidity and seawater and marine life a dramatic erosion corrosion, resulting in the carrying capacity of offshore platform structure decreases. Therefore, the study of the structure performance of marine platform is very necessary.This paper studies a jacket platform in South China Sea area, using ANSYS finite element software, using the numerical simulation method for jacket platform under the non initial imperfection and the corrosion damage to do research the static, modal, transient dynamic,ultimate bearing capacity and corrosion damage evaluation.1. According to a jacket platform of South China Sea design specification, this paper using ANSYS software to set up finite element model. First, carrying on the static analysis of the model, through the combined stress UC value check by the main rod, the result is far less than1; and then the modal analysis, the calculated platform of low-level frequency similar to design, thus verified the accuracy of the model. Based on this model, under different load conditions, the transient dynamic analysis and ultimate bearing capacity analysis, the results show that the carrying capacity of the platform is low in the y direction.2. Jacket platform for a long time service in the harsh environment of the South China Sea,which cause the reducing of the jacket platform’s ultimate load because of the severe corrosion. Based on the analysis of the influence of the corrosion of jacket platform and the Paik corrosion model, the paper calculates the platform’s amount of corrosion for 5, 10, 15 and 20 years. In this paper, we get the relationship between the different age and the ultimate bearing capacity and the UC through the mechanics analysis in different working conditions for the finite element model of corrosion damage platform in different service period. The result shows that some members of the platform lose efficacy after the service of 20 years,which need to be strengthened and repaired so that it can continue to service.