Design of two-pass swage autofrettage processes of thick-walled cylinders by computer modeling

Abstract

An ever-increasing industrial demand for pressurized thick-walled cylindrical components drives research and practice to increase their strength–weight ratio, extend their fatigue life, or to increase their pressure-carrying capacity. This can be achieved through an energy-efficient and safe two-pass swage autofrettage process by generating a favorable compressive residual hoop stress field in the inner layer of the cylinder prior to use. In this paper, a two-pass swage autofrettage process of a thick-walled cylinder was systematically investigated based on finite element analysis. A 105 mm cannon barrel made of high-pressure vessel steel ASTM A723-1130 was taken as a case study. An elastic nonlinear-hardening plastic material model with the Bauschinger effect was adopted. The mandrel’s axial pushing forces during swage autofrettage processes were analyzed. A 30–35% reduction in mandrel’s pushing forces has been achieved in the two-pass process. The residual stresses in swage autofrettaged thick-walled cylinders were predicted. The results of computer modeling were in agreement with neutron diffraction measurements. A maximum 18% reduction in von Mises stress in the swage autofrettaged thick-walled cylinders under an elastic-limit working pressure was identified. A maximum 31% increase in pressure-carrying capacity for the swage autofrettaged thick-walled cylinders was revealed. The optimum radial interference was proposed. Results from the two-pass process were compared with those from the single-pass process.

Simulation Research on Residual Stress of Swage Autofrettage-processed High-Pressure Cylinder

“…Many experts and scholars have researched autofrettage technology. Hu [1] obtained residual stress results consistent with neutron diffraction measurements by numerically modeling the autofrettage procedure in a cylinder with thick walls. Li [2] obtained the optimum autofrettage pressure by simulating the residual distribution of stress within the autofrettage high-pressure cylinder while considering the Bauschinger effect.…”

A Study on Analytically and Numerically Analysis of a Cylindirical Component Using Autofrettage

“…Accurate analytical modeling of swage autofrettage is difficult, as the contact mechanics problem in Swage autofrettage requires considering both geometry and the effect of material nonlinearity. However, studies on numerical analysis have been carried out by some researchers using the finite element method (FEM) for the modeling of swage autofretage [18][19][20][21][22][23][24].…”

Aplicación del proceso de swaging para la generación de tensiones residuales en componentes sometidos a altas presiones

“…También en 2018, Zhong [110] realizó un estudio muy completo de un proceso de autozunchado mecánico en dos pasadas mediante simulación FEM. Para ello consideró un cañon de 105mm de calibre en un material elásto-plástico con endurecimiento no lineal con efecto Bauschinger (Figura 2.32).…”

“…Este método ha sido utilizado por varios autores como Underwood et al [119] y Zhong [110] para la medición de tensiones residuales en cilindros de pared gruesa.…”