Burst pressure estimation of Alloy 690 axial cracked steam generator U-bend tubes using finite element damage analysis

Abstract

This paper presents numerical estimation of burst pressures of axial cracked U-bend tubes, considering the U-bending process analysis. The validity of the FE simulations is confirmed by comparing with published experimental data. From parametric analyses, it is shown that existing EPRI burst pressure estimation equations for straight tubes can be conservatively used to estimate burst pressures of the U-bend tubes. This is due to the increase in yield strength during the U-bending process. The degree of conservatism would decrease with increasing the bend radius and with increasing the crack depth.

Keywords

• Alloy 690 steam generator U-bend tube
• Burst pressure
• Finite element damage analysis
• Strain hardening due to the U-bending process