Elastic-plastic analysis for the deep-sea Ti-alloy pressure vessel subjected to external hydrostatic pressure

By using the general FEM software of MSC. Marc Mentat 2005, the elastic-plastic buckling analysis of deep-sea submarine pressure vessel was conducted. The critical load obtained from elastic buckling analysis is consisted with those from classical theories, and they are much larger than those from plastic buckling analysis. It shows that structural plastic buckling due to the high external hydrostatic pressure is dominant risk factor for deep-sea pressure vessel, and plastic buckling with three-dimensional 8-nodes iso-parameter elements is necessary to give a precise buckling prediction. MSC. Marc Mentat 2005 is efficient for the analysis of the deep-sea pressure vessel, and it provides a reliable method to improve the design of deep-sea pressure vessel further.