The Earthquake Engineering Online Archive

The design of steel energy-absorbing restrainers and their incorporation into nuclear power plants for enhanced safety (final technical report, vol 1A): Piping with energy-absorbing restrainers: parameter study on small systems

Powell, Graham H.; Oughourlian, Carlo V.; Simons, Jeffrey W.

UCB/EERC-80/06, Earthquake Engineering Research Center, University of California, Berkeley, 1980-06, 80 pages (530/D38/1980/v.1A)

This report presents results of an analytical parametric study of small piping systems fitted with energyabsorbing restrainers and subjected to seismic loading. The investigation extends a previously reported study. Two small piping configurations have been investigated in detail for a variety of restrainer locations, restrainer strengths, and seismic excitations. A larger system has been analyzed for one set of parameters only. Studies were carried out on the effects of restrainer strength and location, the sensitivity of response to minor changes in restrainer location, and the effects of viscous damping, out-of-phase support motions, and restrainer preloading resulting from thermal expansion of the piping. It is concluded from an analysis of the results that the stresses calculated for the piping system fitted with energy-absorbing restrainers are consistently and substantially lower than the stresses calculated for piping systems fitted with rigid restrainers. The deformations in the piping fitted with energy-absorbing restrainers are not excessive, and ductility demands on the restrainers are not large. It is recommended that experimental studies be carried out to confirm the theoretical conclusions.

Available online: http://nisee.berkeley.edu/documents/EERC/EERC-80-06.pdf (2 MB)