Energy harvesting in a slender-rod model with modal asynchronicity

The motivation for this paper comes from offshore engineering, in which pre-stressed heavy chains, vertical cables, and rods attached to floating buoys are subjected to imposed heave motions induced by waves. Hence, the energy source in these systems is provided by parametric excitation. A piezoelectric element conveniently coupled to a slender-rod model is studied herewith. It is seen that if the system is tuned into modal asynchronicity, it has a superior performance, as far as energy harvesting is concerned. The very concept of modal asynchronicity, which is not widely spread, is addressed, establishing its phenomenological connection with localisation. Also, the so-called inverse effect associated with piezoelectricity is discussed to explain both the system’s quasi-static and dynamical behaviours.