深海载人潜水器耐压球壳的非线性有限元分析

潜水器耐压球壳的稳定性是开发深海载人潜水器的关键技术之一,其球壳已达中厚壳范围,因此需考虑横向剪切变形的影响.本文基于非线性有限元方法,对大深度载人潜水器耐压球壳的非线性稳定性进行了研究,考虑了加工过程造成的不圆度、材料屈服引起的应变强化呈现的材料非线性、以及壳体整体屈服产生的塑性大变形而表现的几何非线性等因素的影响.计算表明,相同厚度耐压球壳的失稳临界压力随半径的增大而减少;球壳半径不变时,失稳临界压力则随厚度的增加而增大.文中给出了球壳失稳临界压力、厚度与直径的关系曲线,据此可选择潜水器耐压球壳的最佳几何尺寸.

Nonlinear Finite Element Analysis of Pressurized Spherical Shell for Manned Deep Submersible

One of the main problems of developing manned deep submersible is the stability of pressurized sperical shell. Since the pressurized spherical shell belongs to moderately thick shell, it is necessary to take into account transverse shearing deformation. Based on nonlinear finite element method, the stability of the pressurized spherical shell for manned deep submersible is studied in this paper. The influences of out of roundness under machine process and the interaction between material nonlinear and geometry nonlinear on the stability of the shell are considered. They are caused by material yield, strain intensifying and big plastic deformation of the whole shell structure buckling. The calculation results show that the instability pressure decreases with the increasing of the radius under the same thickness but increases with the increasing of the thickness under the same radius. The relationship charts of instability pressure, thickness and radius of pressurized spherical shell are established, so the reasonable geometric parameters of submersible pressurized shell are selected according to the charts.