Reliability assessment and electromagnetic controller for semi-active impact damper in structural vibration control

This study proposes a semi-active controller for impact dampers to address the challenge of achieving ideal impacts that occur exclusively when the structure reaches to its equilibrium position. The control effectiveness and reliability of the semi-active impact damper (SAID) both over time and with parameter variations are assessed and compared with passive impact dampers. Furthermore, the performance of SAID under deviations from the ideal control strategy is investigated, considering three types of non-ideal impact time and friction effects. The mathematical solution for the ideal control strategy is derived, and a strong positive correlation is found between control efficiency and SAID parameters through theoretical analysis and numerical simulation. The corresponding suggestions are provided for addressing parameter variations and deviations from ideal control strategy of SAID. Based on the investigation of extended impact conditions, a feasible SAID controller configuration with adjustable gap clearance is proposed, effectively addressing time lag issues. Experimental results validate the numerical method and practical implementation of the proposed electromagnetic controller for SAID, which can efficiently control structural responses under random low-frequency excitations such as earthquakes.