Influence of initial imperfections on ultimate strength of spherical shells

• Main Authors: Chang-Li Yu, Zhan-Tao Chen, Chao Chen, Yan-ting Chen
• Format: Article
• Language: English
• Published: Elsevier 2017-09-01
• Series: International Journal of Naval Architecture and Ocean Engineering
• Subjects: Ultimate strength; Spherical shells; Residual stress; Initial imperfections; Submersibles
• Online Access: http://www.sciencedirect.com/science/article/pii/S209267821630440X

Comprehensive consideration regarding influence mechanisms of initial imperfections on ultimate strength of spherical shells is taken to satisfy requirement of deep-sea structural design. The feasibility of innovative numerical procedure that combines welding simulation and non-linear buckling analysis is verified by a good agreement to experimental and theoretical results. Spherical shells with a series of wall thicknesses to radius ratios are studied. Residual stress and deformations from welding process are investigated separately. Variant influence mechanisms are discovered. Residual stress is demonstrated to be influential to stress field and buckling behavior but not to the ultimate strength. Deformations are proved to have a significant impact on ultimate strength. When central angles are less than critical value, concave magnitudes reduce ultimate strengths linearly. However, deformations with central angles above critical value are of much greater harm. Less imperfection susceptibility is found in spherical shells with larger wall thicknesses to radius ratios.