Research On The Ultimate Bearing Capacity Of Deep Submergence Pressure Cylinder Shell

Pressure cylinder shell is the major structure of deep submergence vehicle. The main purpose of this paper is to research the ultimate bearing capacity of deep submergence pressure cylinder shell.Firstly, this paper analyze the ultimate bearing capacity of three model by ANSYS. The eigenvalue buckling mode which is obtained by elastic buckling analysis is added to the original model to analyze elastic-plastic buckling. Comparison results show that the submarine design specification is safe. By comparing calculated values with submarine design specification formula and the correction formula results, it indicates that the submarine design specification is safe. Local stability calculation formula need to be revised due to its conservatism under the condition of big depth and high strength material applications.Secondly, through the discussion of the non-uniform ribbed analysis, this paper study the principles and steps of non-uniform ribbed. Taking the stiffness non-uniform ribbed can improve the stability of the long pressure hull which has much frame as much as possible.In addition,frame spacing non-uniform ribbed are applicable to all of pressure shells whose stability of rise is larger.Then, this paper research the measures of frame lateral strengthening. Through the finite element calculation, it is concluded that setting the whole rib spacing bracket can significantly improve the frame lateral buckling and strengthen material number can be calculated by formula.Finally, by comparing and analyzing the different type of cylindrical shell stability of strengthening rib, we found that overall stability performance of T bar reinforced ring rib pressure shell and shell stability performance of half ring shell reinforced pressure shell is best. Under the total amount of guarantee the frame material, the stability of shell fall slightly after adjusting half the size of the ring and shell and the overall stability is improved greatly.It is considered that the half circle shell frame which is used to strengthen cylindrical shell is feasible.But it is necessary to calculate the optimal size while designing the structure.