Efficient dynamic structural response modelling of bolted flange piping systems

The dynamic structural response of piping systems is studied and effective analysis techniques are recommended to assess the influence of a bolted flange with an elastic gasket. The influence of an elastic gasket is minimal for dynamic loadings, as shown in both the experimental and numerical results presented. An overhanging piping system at various span lengths with a flange at mid-length is used for a broad evaluation of potential applications. The testing configurations consist of two different diameter pipes, standard 2 (51 mm) and 4 in (102 mm) schedule 40 steel pipes and the corresponding ANSI B16.5 class 300-pound flanges. Included are fundamental resonant frequencies and their respective mode shapes for various span lengths and gasket configurations using experimental and finite element (FE) methods. The complex interaction between the flange and gasket has little impact on the dynamic structural response of a piping system. The results show that simple lumped mass pipe models provide adequate information in assessing dynamic behaviour of piping systems.