焊接残余应力对深潜器耐压球壳承载能力的影响

Effect of welding residual stress on the ultimate strength of spherical pressure hull

耐压球壳通常采用焊接方式将两个半球壳连接成整球,在焊缝处产生的接近材料屈服强度的焊接残余应力对球壳的承载能力有多大的影响,是否需要做焊后消除残余应力处理,将直接影响球壳的安全性和生产成本。而现有对球壳极限强度计算,无论是理论计算还是数值计算,均只考虑了球壳初始缺陷中的几何缺陷对球壳极限强度的影响。该文将在现有的耐压壳极限强度设计公式基础上,采用数值计算的方法对耐压球壳的焊接过程进行数值模拟,得到焊后球壳的焊接残余应力分布,并在此基础上考虑残余应力对球壳极限强度的影响,结果表明,对于大潜深厚球壳,焊接残余应力对耐压球壳承载能力影响不显著,为大深度潜器耐压球罐是否需做焊后消除残余应力处理提供了一定的参考依据。

The present theoretical and numerical calculation on the ultimate strength of spherical pressure hulls only take the initial displacement imperfection into consideration. However, it will bring welding resid-ual stress when constructing a spherical pressure hull, then it is necessary to evaluate the effect of welding residual stress on the ultimate strength of spherical pressure hull. In this paper, a series of current existing empirical design rules and equations was used to calculate the ultimate strength of pressure hull. Com-bined with the FEM method, the welding numerical simulation of the spherical pressure model was conduct-ed and the welding residual stress distribution was given. Finally, the effect of welding residual stress on ultimate strength of spherical pressure hull will be investigated and the results of this paper will offer some guide for the fabrication process of postweld heat treatment.