Quantities Affecting the Behavior of Vibrational Magnetostrictive Transducers

Abstract

Through the conversion from mechanical to ele ctrical energy it is possible to monitor a vibrating machine of any kind, by exploiting the mechanical energy produced by the vibration. To this end, one can use direct force devices inserted in the supports or in the kinematic chain of the vibrating contrivance, or cantilever devices with seismic masses. Regarding the devices of the first t ype, the maximization of the electrical output depends on various parameters. This work, through a combined experimental and modeling approach, analyzes the behavior of a transducer based on a rod of Terfenol-D. Many parameters are analyzed, such as the frequency of the vibration, the amplitude of the force transmitted by the vibration, the characteristics of the coupled electrical circuit, the magnetic and mechanical bias. It is shown how the output power and electrical current are strongly influenced by the mechanical and magnetic bias. In addition, avoiding tensile stresses, the work shows how the maximum output power is obtained when the mechanical bias is close to the amplitude of the dynamic force imposed by the vibration.

A Review on Piezoelectric, Magnetostrictive, and Magnetoelectric Materials and Device Technologies for Energy Harvesting Applications

“…This generated 2.17 V (peak value, using a coil of 267 turns) with a 10 MPa compressive load. The power Zucca et al [79] analyzed the factors that influence the performance of a Terfenol-D rod and showed that the induced electrical current and power have a complex dependence on several quantities, namely the coil characteristics, type of permanent magnets, and characteristics of the mechanical excitation. The power Zucca et al [79] analyzed the factors that influence the performance of a Terfenol-D rod and showed that the induced electrical current and power have a complex dependence on several quantities, namely the coil characteristics, type of permanent magnets, and characteristics of the mechanical excitation.…”

“…Viola et al [78] proposed an approach to designing a Terfenol-D power generator for energy harvesting from traffic vibration and validated it experimentally. The power Zucca et al [79] analyzed the factors that influence the performance of a Terfenol-D rod and showed that the induced electrical current and power have a complex dependence on several quantities, namely the coil characteristics, type of permanent magnets, and characteristics of the mechanical excitation. In particular, the magnetic and mechanical bias were of great importance in terms of power (82.8 mW).…”

Equivalent Strain and Stress Models for the Effect of Mechanical Loading on the Permeability of Ferromagnetic Materials

“…The proposed equivalent strain/stress approach is tested with the three multiaxial stress configurations σequ, σsh1 and σsh2 shown in (3), when σ varies between -30 and +30 MPa. The idea is to obtain the relative permeability μr = B/(μ0Hx) under the three stress configurations simply by interpolating from the μr(σ) relationship measured under σuni (markers in the top-left part of Fig.…”

“…AGNETO-MECHANICAL interaction causes additional losses and permeability degradation in electrical machine cores [1]. On the other hand, the same effects can be utilized for harvesting electrical energy from mechanical vibration [2], [3]. Complex multiaxial strains and stresses may occur in such applications, but identification measurements are most commonly available only under uniaxial stress parallel to the magnetic field [4]- [5].…”

A Magnetostrictive Electric Power Generator for Energy Harvesting From Traffic: Design and Experimental Verification

“…ECENTLY MANY energy harvesting systems based on magnetostrictive materials have been proposed [1][2][3][4][5][6][7] . In magnetostrictive materials, the application of an external mechanical force induces a change in the level of magnetization and consequently an electromotive force (emf) is generated.…”