Intersecting bore geometries are used in a number of industrial application
s 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 reduct
ion 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 fa
tigue lives necessitates accurate evaluation of the residual stresses induc
ed by autofrettage. In this paper, finite element models were used to obtai
n hoop stress to pressure ratios, at the most highly stressed plane, in blo
cks 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 aut
ofrettage pressure and to estimate the elastoplastic residual stresses on t
his plane. The suggested method estimates residual stress magnitudes close
to finite element solutions, and eliminates the need for a lengthy and cost
ly elastoplastic finite element analysis. (C) 2001 Elsevier Science Ltd. Al
l rights reserved.