Analytically predicting the burst pressure of composite rupture discs by considering nonlinear strain path

Abstract

The composite rupture discs are a safety device that burst at the specified pressure and prevent overpressure and damage to equipment by releasing the fluid at high flow rates. The burst pressure is determined by the bulge formed and then slotted sheet metal. In the hydraulic bulge-forming stage, the sheet is subject to biaxial stress, and after slotting, it is subject to uniaxial tensile stress. Due to the change in the loading type, the sheet has a nonlinear strain path during the bulge-forming and burst test after slotting. In the nonlinear strain paths, the equivalent failure strain changes according to the strain path. In this paper, based on the FEM simulation results and experimental tests, the relationship between plastic failure strain in uniaxial tensile state and the maximum pre-strain due to bulge forming is investigated. According to the results of this paper, when the sheet sufficiently forms under hydraulic pressure, the maximum strain in hydraulic bulge-forming and the equivalent failure strain after slotting are equal. Based on this result, analytical relations were developed to predict the burst pressure of composite rupture discs. This relation estimates the burst pressure of composite rupture discs with an average error of about 13%.