Numerical simulation and experimental validation of the seismic response of suspended grooved-fit piping systems

Robust internal building pipeline is one of the most important non-structural components for reducing post -earthquake secondary disasters and maintaining normal use of buildings after an earthquake. The seismic damage of piping systems can result in the loss of firefighting abilities or lead to failure of water supplies and drainage systems in a building which can have serious implications for emergency rescue, post-disaster response and reconstruction work. In this study, moment-rotation hysteresis curves of grooved-fit piping-joints are ob-tained by quasi-static cyclical tests. Moment-rotation hysteresis models of piping-joints are developed using the Pinching4 uniaxial constitutive in the finite element software OpenSees. The calibrated model parameters are obtained using test data. The developed hysteresis models can accurately reproduce the moment-rotation hys-teresis curves obtained in the experiments and simulate moment time-history during the loading process. The predicted accumulated energy dissipation is consistent with the test results. Using this observation, generic piping-joint moment-rotation hysteresis models are further developed and parameter values used to define the generic hysteresis model are obtained. A numerical model of a piping system is then developed using the generic hysteresis model. The numerical results confirm that the model can be used to reproduce the nonlinear behavior of a piping system under cyclic loading with high accuracy. The developed numerical model was further cali-brated using shaking table test results. Comparisons between numerical and experimental responses demonstrate that the developed numerical model can be used to analyze the seismic response of a suspended piping system using grooved-fit joints.