考虑实测初挠度、厚度和残余应力等缺陷的耐压球壳极限承载力分析

Ultimate strength analysis of pressure spherical hull with initial defection, thickness and residual stress imperfection

由于其优良的承压性能,球壳常被用作深海设备的耐压结构,而耐压球壳极限承载力计算是球壳结构设计过程中的重要环节。文章在非线性屈曲分析有限元法的基础上,提出了考虑实测初挠度、厚度和残余应力的极限承载力计算方法,并加工了直径1000 mm的耐压球壳进行了试验验证。结果表明:经过冲压、焊接等工艺制造的球壳具有明显的初始缺陷,计算过程中必须考虑极限承载力;残余应力中影响极限承载力的主要因素是压应力成分;基于实测数据的非线性屈曲分析方法计算结果与试验值接近,且能够粗略预报结构破坏位置,具备一定的适用性。

Pressure spherical hull plays an important role in deep-sea pressure structures due to excellent bearing capacity and the prediction of ultimate strength makes a great impact on design.A computing method considering actual initial defection,thickness and residual stress is put forward on the basis of nonlinear buckling analysis in the paper.A test model with a diameter of 1000 mm is manufactured to verify the meth od.Research shows that the manufacturer defect must be considered.Residual compressive stress weakens bearing capacity in comparison with residual tensile stress.The calculation results based on initial imperfec tion of test model are in agreement with the experiment results.