Bench-scale nonlinear test structure for structural control research

Experimental verification of analytical and numerical studies is very important in the area of structural dynamics and control due to the presence of higher mode participation, control structure interaction, sensor noise and potential nonlinear behavior. This paper describes a bench-scale test structure that extends the typical capabilities of test structures able to incorporate higher mode participation, control structure interaction and sensor noise to include nonlinear material behavior. A portal frame test structure is designed and built to simulate the formation of plastic hinges without actually receiving any damage. To demonstrate the nonlinear test structure’s use, a semiactive control strategy employing a shear mode magnetorheological (MR) fluid damper and acceleration feedback is applied to the test structure for seismic protection. The performance of the semiactive controlled structure is compared to the uncontrolled structure for a broad range of ground motion intensities and varying levels of nonlinear structural behavior to observe the improved reliability of the semiactive controlled structure.