Theoretical analysis and experimental research into the integral hydro-bulge forming of oblate shells

The integral hydro-bulge forming technology of oblate shells is researched theoretically and experimentally. The self-adjusting theory of plastic deformation of polyhedral shells is introduced first, the features of the stress distribution and plastic deformation of the oblate shells being discussed. The hastening-sphere deformation procedure, the variational tendency of the shell axes and the plastic deformation procedure are investigated. Experimental results are presented and discussed. It is proven experimentally that the hastening-sphere effect is suitable for the hydro-bulging of oblate shells and the prospects of the integral hydro-bulge forming technology of oblate shells are demonstrated.