Semi-active vibration control based on switchable transfer of bending moments: study and experimental validation of control performance

Abstract

This paper presents an experimental approach to assessment of semi-active vibration control systems based on the Prestress–Accumulation Release concept. The objectives are threefold: (1) to introduce an experimental validation method for control algorithms based on switchable transfer of moments, (2) to propose a method to assess experimentally the control effects on structural dynamic response under several types of excitation, and (3) to propose an approach for adequate sensor placement. A laboratory frame demonstrator equipped with dedicated semi-active nodes is used. The proposed approach is based on spectral responses and modal analysis. According to the presented findings, the investigated control is effective in reducing the vibration level while keeping the structural dynamic stiffness at a proper level. The investigation is conducted in the case of free response, as well as responses to impact loading and random excitation. The results confirm the accuracy of the adopted algorithm parameters and reveal the sensor locations that provide the best control effectiveness.

Experimental Verification of a Semi-Active Modal Control Algorithm for Structures With Lockable Joints

“…In the unlocked mode of operation, the frame response is shifted out of the resonance what additionally reduces the amplitude. Therefore, it should be taken into consideration that the dynamic stiffness parameter of the locked and controlled frame is kept constant as revealed in [12] and those two results should be treated as meaningful in the analysis. Therefore, the measured 47 % in reduction might be considered as the respective effectiveness of the method in this example.…”

Semi-Active Sliding-Mode Control for Local Mitigation of Structural Vibrations by Means of on/Off Nodes

“…Such joints are essentially frictionbased lockable hinges, and early control laws aimed to stimulate local dissipation by maximizing nodal force-displacement hysteresis [17,18]. However, these nodes can also be utilized to trigger the transfer of vibrational energy to high-order modes, which are more effectively damped by standard material damping mechanisms compared to low-order modes [19]. The control laws involved are either simple heuristics [20] or more formal and explicitly aimed at modal energy transfer [21].…”