Investigation of Autofrettaged Thick-walled Cylinders with Axial Holes Machined

Abstract

The redistribution of residual strains in autofrettaged thick-walled steel tubes resulting from the introduction of holes machined at a radial distance, 50% of the plastic boundary has been investigated with neutron diffraction and finite-elements. In the high compressive region, the redistribution is observed to be localized close to the hole. On the outer section of the hole, the redistribution is less dramatic, but extends up to the plastic boundary. A finite-element simulation of the redistribution of the residual stresses based on an equivalent thermal field approach, based on the measured residual strain values in the solid tube, is also presented.