An analytical procedure for estimating residual stresses in blocks containing crossbores

• Published in: The International journal of pressure vessels and piping 2000-10, Vol.77 (12), p.737-749
• Main Authors: Badr, E.A, Sorem, J.R, Tipton, S.M, Yang, S
• Format: Article
• Language: English
• Subjects: Autofrettage; Computational techniques; Exact sciences and technology; Finite element models; Finite-element and galerkin methods; Mathematical methods in physics; Physics; Residual stresses
• ISSN: 0308-0161; 1879-3541
• DOI: 10.1016/S0308-0161(00)00064-8

Intersecting bore geometries are used in a number of industrial applications such as the fluid ends of reciprocating pumps and have regions with high stress concentration. To increase the fatigue life of a fluid end, a reduction in the operating mean stress is helpful. This can be achieved with the introduction of compressive residual stresses in these critical regions by means of proof loading or autofrettage. Accurate estimation of fluid end fatigue lives necessitates accurate evaluation of the residual stresses induced by autofrettage. In this paper, finite element models were used to obtain hoop stress to pressure ratios, at the most highly stressed plane, in blocks of different sizes and bore ratios. The hoop stress to pressure ratios were used along with Neuber's rule and kinematic hardening to select an autofrettage pressure and to estimate the elastoplastic residual stresses on this plane. The suggested method estimates residual stress magnitudes close to finite element solutions, and eliminates the need for a lengthy and costly elastoplastic finite element analysis.