Study of a spherical shell with a surface crack by the line-spring modle

摘要

The Sih and Hangendorf shell throty and the line-spring model are used to derive the governign equations of the spherical shell with a semi-elliptical interanl or external surface crack. By assuming the functions of the displacement adnd the rotation as u=C_i(1-η~2)~(1/2) and β=D_i(1-η~2)~(1/2), the computation of governing equations is simplified into linear algebraic equations through the proper treatment of singular equations. Displacement and stress fields for the spherical shell with a surface crack are calculated and the stress intensity factor at every point of the surface crack front is given in the paper. By comparison with the modified factor, the line-spring model gives the expected results.