Design of externally pressurized ellipsoidal heads with variable wall thicknesses

Abstract

This study focused on the buckling and strength of ellipsoidal heads with variable wall thicknesses under uniform external pressure. The wall thickness of ellipsoidal heads was designed according to the isostrength principles. The wall thickness distribution of revolution for thin shells were proposed, and the effect of the thickness distribution on the strength of the ellipsoidal head is explored. The buckling of the ellipsoidal heads with variable thicknesses and constant thicknesses were evaluated numerically using the modified Riks method, and the effect of the ellipticity on the buckling performance of the ellipsoidal head was explored and the optimal ellipticity was presented. The results revealed that the buckling load of the ellipsoidal head with variable wall thickness was approximately 17% higher than that of the ellipsoidal head with constant wall thickness, while the volume decreased by 5%. This study can guide the structural design of ellipsoidal heads with variable wall thicknesses.