REAL-TIME DYNAMIC HYBRID TESTING OF STRUCTURALSYSTEMS

摘要

This paper presents the development and implementation of a novel structural testing method involvingthe combined use of shake tables, actuators and computational engines for the seismic simulation ofstructures. The structure to be simulated is divided into one or more experimental and computationalsubstructures. The interface forces between the experimental and computational substructures are imposedby actuators and resulting displacements and velocities are fed back to the computational engine. Theearthquake ground motion is applied to the experimental substructures by shake tables. The unique aspectof the above hybrid system is force-based substructuring. Since the shake tables induce inertia forces inthe experimental substructures, the actuators have to be operated in dynamic force control as well, sinceeither the force or the displacement, but not both can be controlled at a given point. The resulting testingmethod is more versatile that existing seismic testing methods. First the substructuring strategy and thenumerical integration algorithms associated with the computational substructures are discussed along withthe implementation of the computational engine. Then the theory of dynamic force control and twodifferent force control algorithms, one based on real-time convolution and the other on series elasticity, aredescribed. Issues related to time-delay compensation are also discussed. The real-time hybrid system isimplemented using a distributed architecture based on the replicated shared memory concept. Thearchitecture allows for flexibility in the design of the system and in the components used. This real-timearchitecture is discussed next. An example of a real-time hybrid test is presented next.