FEASIBILITY STUDY ON ENERGY HARVESTING FROM VERTICAL BEAM EXCITED BY VERTICAL BASE EXCITATION
Prathap Kumar1, Suresh K2, Rajarathinam M3, Sharanabasappa Sajjan4
1,2,4Department of Mechanical Engineering, Government Engineering College (Affiliated to Visvesvaraya Technological University, Belagavi), Talakal, Koppal, India
3Department of A. B. M., LUT, Poland
Abstract: A nonlinear energy harvesting system is proposed, consisting of a tip-loaded slender vertical cantilever beam with a strain gauge attached. The beam is oriented with its free end pointing upward and its fixed end at the bottom, and is subjected to vertical base excitations. Under such excitation, the slender beam experiences a compressive force resulting from both the base motion and the tip mass. The theory of buckling is explored, and it is shown that beyond a critical value of the crippling force, the beam undergoes buckling. To understand the system’s stability, the potential energy equation is analyzed, revealing conditions for monostability, biostability, and stochastic responses. Free vibration tests and corresponding simulations show good agreement in the natural frequencies of the proposed beam. Experimental results under frequency-swept vertical excitation demonstrate that the combined inertial forces from the tip mass and base motion can transform the system’s behavior from monostable to bistable. This resulted in non-linear large amplitude horizontal vibrations of the harvester. The strain gauge measurements confirm the feasibility of using this vertical cantilever beam for the efficient vibration energy harvesting.
Keywords: Nonlinear, Energy Harvesting, Piezoelectricity, Vibration