Analytical Modeling of the Contact Stress With Nonlinear Gaskets

Abstract

Gasket contact stress and its variation through the gasket width is caused by the rotation of the flange and has an influence on the leakage tightness behavior of bolted flange joints. The future implementation by the ASME of proposed design rules is based on new gasket constants obtained from the ROTT (room temperature tightness) tests conducted on rigid platens. The gasket contact stress distribution needs to be addressed for the purpose of better joint tightness predictions. This paper presents a comprehensive analytical method that predicts the gasket contact stress distribution taking into account the nonlinear mechanical behavior of the gasket material. Based on the flange rotational flexibility, the proposed analytical model that is implemented in the “SuperFlange” program is supported and validated by numerical FEA and experimental analyses on flange rotations, radial distribution of gasket contact stress, and joint leak tightness.