UBC Theses and Dissertations
Verification of an analytical hysteresis model for dowel-type timber connections using shake table tests Wong, Ernie Y.
The purpose of this study was to verify the analytical results of a non-linear finite-element model for predicting the seismic response of ductile dowel type moment-resisting connections. The analytical model, FRAME, is based on each dowel modelled as an elasto-plastic beam in a non-linear medium, thus allowing the formation of gaps between the beam and the medium. The model calculates the response using basic stress/strain information of the connector and the surrounding medium. The advantage of using basic material properties is that the model can automatically adjust to any connection configuration and input history. To validate the results of the analytical model, four test specimens were built and tested on the UBC Earthquake Engineering Shake Table. The objective was to assess the analytical model, to see if its results could accurately simulate the response of connections subjected to different earthquakes and with different configurations. The specimens were made from parallel strand lumber (Parallam®), connected to the shake table by steel plates and tight-fitting mild steel dowels. A mass was placed on top of the column to simulate building loads. A Northridge(1994) and a Kobe(1995) earthquake record were used in this experiment. The relative displacements at the top and bottom of the column were obtained from the tests and used to verify the results from the analytical model. The basic material properties used in the analytical model were obtained through wood bearing tests on the Parallam® and tensile yield tests on the steel dowels. The comparison of the experimental results with the analytical predictions from FRAME showed that FRAME can accurately model the seismic response of ductile dowel-type timber connections. Of particular importance was the fact that FRAME is able to adapt to different connection configurations and different excitation signals.
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