Three-Dimensional Nonlinear Finite-Element Analysis of Gasketed Flange Joint under Combined Internal Pressure and Variable Temperatures

Abstract

Performance of a flange joint is characterized mainly due to its “strength” and “sealing capabilit.” A number of analytical and experimental studies have been conducted to study these characteristics only under internal pressure loading. The effect of steady state thermal loading is a well recognized problem and makes the problem more complex under combined application of internal pressure and temperature. To investigate fundamental joint characteristics, joint strength and sealing capability under combined internal pressure, and variable steady state thermal loading, a three-dimensional nonlinear finite-element analysis of gasketed flange joint is carried out using ANSYS commercial software. Reduced joint strength is concluded due to the flange rotation resulting in flange yielding under bolt up and applied operating conditions. Reduced joint sealing is concluded due to the variation in gasket seating or contact pressure due to bolt load variation. Flange rotation, bolt bending, and joint relaxation concluded fatigue and dynamic behavior in the gasketed joint. These effects are observed to be more pronounced at higher temperatures. Verification of finite-element model with available classical theories is also performed and discussed.