Verification of piping response calculations of SMACS code with data from seismic testing of an in-plant piping system

The objective of this effort was to evaluate the piping analysis part of the SMACS code for estimating the response of realistic piping systems subjected to seismic excitation, given as multiple, independent support acceleration histories. The experimental data from the seismic testing of an in-plant piping system at the HDR Test Facility in Germany were used for this purpose. Of the six different support systems tested, two were selected for the evaluation: one a stiff'' configuration containing both struts and snubbers, and the other, a more flexible configuration with no snubbers. Described are the analytical modeling, calculations, and results of the posttest simulation of two sets each for both support configurations, with excitations at 100% and 200/300% of safe-shutdown-earthquake loading. Almost all the calculated peak response quantities were smaller (by different amounts) than the corresponding test measurements. However, pipe displacements and bending stresses were better estimated than the pipe accelerations and support forces. The discrepancies are mainly attributable to the inability of the linear analysis to model the nonlinear behavior of the VKL piping system, characterized by gaps in support connections and the friction at pipe clamps. A similar trend of underestimating test responses was observed in the linear analyses more » performed by other investigators. 13 refs., 14 figs., 8 tabs. « less