Publication

Abstract : In this study, the adverse effect of an inadequately designed input control force was experimentally investigated in view of the excitation of the torsional modes of a structural system. The initial formulation was developed based on a generalized symmetric structural system under PD, PI, and PID control strategies that aimed at controlling the lateral modes of the structural system. Based on the control design, an experimental investigation was carried out on a single-story symmetric frame structure under the three designed control conditions using an Arduino-based data acquisition system. The structure was subjected to sinusoidal excitation with different frequency ratios and white noise excitation. In the next step, the system was perturbed by reducing the column stiffness in a way, that made the center of mass and the center of stiffness different. The perturbed structural system was also provided with the same initially designed input control forces under the same set of external excitations. Responses of the different control algorithms were recorded and analyzed considering the excitation of the torsional mode of the perturbed system. A significant excitation of the torsional mode was noticed in the study, particularly for an excitation near the resonating frequency of the lateral mode of the system.