A Piezoelectric Energy Harvesting Damper for Low-Frequency Application
In this study, a design of an energy harvesting damper for low-frequency applications, such as energy harvesting from long period infrastructures, tanks and pipings, and maritime and offshore structures, is presented. In this design, the low-frequency relative motion of the damper is transformed into a high-frequency motion of a piezoelectric cantilever beam by a mechanical switching mechanism, referred to as “plucking” mechanism that couples and decouples the cantilever to the damper rod so that the input energy into the damper is converted to electric energy with high efficiency. In this paper, the energy harvesting efficiency is theoretically calculated for the harvesters with and without plucking mechanism and the optimized maximum performance is derived. Then the electrical switching circuit for the enhancement of the electromechanical conversion efficiency, referred to as “SSHI” interface is introduced. Numerical case studies suggest that the harvester with an ideally implemented parallel SSHI circuit can retrieve over 70 % energy of the maximum mechanical work input on the damper rod.