UBC Theses and Dissertations
Hybrid simulation and its application to the gravity load collapse of reinforced concrete frames Charlet, Arnaud Yves
The structural testing method called hybrid simulation is implemented at the University of British Columbia. A tutorial is presented to assist the user on how to perform hybrid simulation of structural systems using the finite element software OpenSees, the software framework for hybrid simulation OpenFresco and an event-driven predictor-corrector scheme ensuring continuous testing. Geographically distributed hybrid simulation is introduced and distributed tests performed between the University of British Columbia and the University of California, Berkeley, are described. A hybrid simulation test setup is developed to investigate and validate the application of hybrid simulation to the gravity load collapse of reinforced concrete frames. A shear-critical reinforced concrete column loaded through three dynamic actuators constitutes the physical substructure while a nonlinear ductile reinforced concrete frame makes up the numerical substructure within the OpenSees environment. A nonlinear transformation method is implemented to allow for an accurate application of the three-degree-of-freedom loading on the specimen through the three-actuator test setup, and a specific predictor-corrector algorithm with variable actuator speed is designed to ensure smooth continuous testing despite the use of an implicit iterative integration scheme. Furthermore, a methodology using an iterative predictor-corrector algorithm with mode-switch is developed to enable the use of force control for the actuators in combination with a displacement-based finite element analysis engine. Results from the hybrid tests are compared with a shaking table test of the same structure, and are shown to exhibit the same general behaviour: shear and axial load failure of the shear-critical column followed by gravity load redistribution. However, the inability of the analytical model to capture the residual drifts observed in the shake table tests resulted in an underprediction of the drift demand on the system.
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