Analysis of piezoelectric effects on various loading conditions for energy harvesting in a bridge system

This study examines the PE (piezoelectric) effects on various loading conditions for the possibility of harvesting energy from bridges by converting the potential energy of vibrating bridge systems into electric energy using PE material. A steel beam-slab type bridge specimen is fabricated and PE modules are attached at various positions, where different structural responses are expected under moving vehicles on the bridge. Considering the various traffic conditions, such as vehicle weight and moving speed, load test on the bridge specimen is performed with varying load amplitude and loading frequency. Generated voltage evaluation tests are also carried out in order to assess the PE characteristics of the adopted PE materials. The PE effects are examined under various structural response characteristics of the bridge members. The test results are compared with the well-known analytical formulations of PE effects. The test results indicate that the PE effects are affected sensitively by the strain increasing rate and peak strain of PE materials attached on the bridge members, which will be determined due to the moving speed and weight of moving vehicle on the bridge. Among the analytical formulations widely used to evaluate PE effects, the Euler-Bernoulli model is found to provide the most accurate estimation for the PE effects of the PE modules attached on the bridge members. (C) 2011 Elsevier B.V. All rights reserved.