Claudio D. Gatti, José M. Ramirez, Mariano Febbo and
Sebastián P. Machado
Vol. 13 (2018), No. 1, 17–34
DOI: 10.2140/jomms.2018.13.17
Abstract
In a conventional transport vehicle, only about 10% to 16% of the energy from the
fuel is used to move it down the road. The rest of the energy is lost in the brakes,
transmission, engine, accessories, rolling resistance, aerodynamic drag, and idle losses.
Among all of these, the largest loss is the energy lost in the engine (approximately
63%), which is mostly wasted as vibration. Our work develops an energy harvesting
device that is capable of collecting energy for different gear ratios in a car. For this
reason, the structural design is oriented to create a harvesting structure with several
resonant modes in a frequency bandwidth between 1600 rpm–4600 rpm, which was
the range obtained through driving tests in a conventional diesel car. The
harvesting device is based on a piezoelectric fiber composite beam with a
high fatigue resistance placed in the middle of two mass-spring systems,
which provide the multimodal character of the device. A one-dimensional
analytical model based on a Lagrangian formulation is used to predict the
dynamical behavior of the device. The equations provide a very good quantitative
description of the system, which is also modeled with a three-dimensional finite
element code (Abaqus) for numerical validation. Experimental tests are then
carried out and compared with theoretical findings. The results show a very
good agreement between both of them, revealing the multimodal nature
of the device in the operating bandwidth, with a significant output power
for different engine speeds, sufficient to feed low-power monitoring wireless
systems.
Keywords
piezoelectric materials, vehicles, engines, vibrations,
system recovery