Piezoelectric energy harvesting for civil infrastructure system applications: Moving loads and surface strain fluctuations

This article formulates the problem of vibration-based energy harvesting using piezoelectric transduction for civil infrastructure system applications with a focus on moving load excitations and surface strain fluctuations. Two approaches of piezoelectric power generation from moving loads are formulated. The first one is based on using a bimorph cantilever located at an arbitrary position on a simply supported slender bridge. The fundamental moving load problem is reviewed and the input to the cantilevered energy harvester is obtained to couple with the generalized electromechanical equations for transient excitation. The second approach considers using a thin piezoceramic patch covering a region on the bridge. The transient electrical response of the surface patch to moving load excitation is derived in the presence of a resistive electrical load. The local way of formulating piezoelectric energy harvesting from two-dimensional surface strain fluctuations of large structures is also discussed. For a thin piezoceramic patch attached onto the surface of a large structure, analytical expressions of the electrical power output are presented for generalized, harmonic, and white noise-type two-dimensional strain fluctuations. Finally, a case study is given to analyze a small piezoceramic patch for energy harvesting from surface strain fluctuations along with measured bridge strain data.