SHAKING TABLE TESTING OF NONLINEAR ELASTIC MOMENT RESISTING FRAMES

A scaled physical model of a nonlinear elastic moment resisting frame is designed and tested both statically and dynamically with the aim to validate a numerical model as well as confirm the global properties of this type of structures. The nonlinear stiffness of this type of structures is verified through a static pushover test. Dynamic properties such as the amplitude dependent of the natural frequency are identified. Equivalent viscous damping properties of the physical model are evaluated for a set of different amplitudes through free vibration tests. The data retrieved during physical experiments is used to update a distinct element numerical model of the physical test frame. The physical model is tested under a large number of real ground motion time histories to evaluate the robustness of the structural form. Selections of these tests are run through the updated numerical model to estimate how well the numerical model emulates the physical model. An example of a time history analysis is presented, showing a good comparison between the physical model and the best numerical model. The best numerical model manages to estimate quite well the amplitude and time of the peak response of the structure to the ground motion