Evaluation of damping values of a piping system with regard to damping values used in design codes

Abstract To investigate the damping behavior of an in-situ structure a piping system was subjected to seismic-like loads during the SHAM test series at the HDR test facility in Kahl, FRG. Tests were run using random excitation to identify natural frequencies, mode shapes and damping values for different restraint configurations with MDOF system identification methods. The damping values were achieved concerning the stiffness of the respective restraint configuration. For one restraint configuration tests with earthquake-like excitation were evaluated by fitted parameter calculations for different load levels. This study served to determine the damping values as a function of excitation and stress levels. Both sets of evaluations cover the spectrum of restraint configurations used in practice, trace the load increase, and provide possibilities for comparing the results with pipe damping values used in current design practice.