Defect mitigation and structural control of cantilevered structures using shape memory wire based resonant stiffness sensing

This article presents a resonant sensing and control approach for the structural health monitoring (SHM) and rehabilitation of cantilever mechanical designs where independent, detachable shape memory alloy (SMA) wire with gravity bias functions as a resonating module that resonates the beam. Resonant stiffness sensing is implemented as the diagnostic tool for the structural health assessment, and the motor coupled linear actuation and positioning equipment is used for recuperation in this work. In this implementation, SMA acts as a vibration inducer to generate controlled vibration, and the corresponding resonant frequency shift for the identification of defects in the structure is sensed by an external sensor. The presence of cracks or misalignment on the structure affects the stiffness of the assembly that in turn is realized as a resonant frequency shift. Stiffness, the parameter that is prominently affected due to the deterioration of the health of the structure is controlled by the motor coupled lead screw that positions the cantilever engineering structure with desired stiffness by displacing the flexible beam. The experimental results demonstrate the effectiveness of the proposed approach for SHM and rehabilitation.