Equivalent circuit method based on complete magneto-mechanical coupling magnetostriction parameters for fixed magnetoelectric composites

Sensor applications based on magnetoelectric (ME) effects have the potential to achieve ultra-precise detection. Due to the significant nonlinearity found in the experiment, establishing a systematic nonlinear analysis model is essential for designing high performance ME devices. This paper presents an equivalent circuit method based on complete magneto-mechanical coupling nonlinear magnetostrictive (MS) constitutive parameters for nonlinear analysis of ends fixed ME composites. In order to accurately characterize the nonlinearity of the MS phase in ME composites, a nonlinear constitutive model considering fully magneto-mechanical coupling is employed, and nonlinear MS constitutive parameters can be derived from it. Finally, an equivalent circuit model, which can characterize the nonlinearity of ME composites, is developed. Utilizing this method, the response of ends fixed ME composites at low frequency range and around resonant frequency can be predicted. The influences of prestress, bias magnetic field and length ratio of MS phase and piezoelectric phase on the ME response are also investigated with this method. Moreover, an ends fixed ME composites is fabricated and the performance for AC/DC current is tested. The experimental results demonstrate the effectiveness of the proposed equivalent circuit model and the ? noise density is 6.08 nV/ Hz . In addition, the detection accurate for AC and DC current is better than 0.4 mA and 5 mA, respectively. This research can provide theoretical basis for the optimal design of sensors and other devices based on ME composites.