Nonlinear magneto-electric response characteristics of giant magnetostrictive-piezoelectric composite sensors in harmonic and stochastic magnetic fields were studied in this paper. Van der Pol nonlinear difference items were introduced to interpret the hysteresis phenomena of both giant magnetostrictive material and piezoelectric ceramics. The nonlinear dynamic model of giant magnetostrictive-piezoelectric composite sensors in harmonic and stochastic magnetic fields was developed. The expression of dynamic response of the system was obtained, and the bifurcation characteristics of the system were analyzed. The magneto-electric coefficient of the composite sensors was determined, and the effects of system parameters on the dynamic characteristics and magneto-electric coefficient of the system were analyzed. The simulation results show that there are stochastic Hopf bifurcation and jump phenomena of vibration amplitude in the system, and both of that can be avoided through adjusting parameters. The experimental results show that the system’s motion becomes chaotic when stochastic excitation is extremely large. The results of this paper are helpful for optimal design and improvement of giant magnetostrictive-piezoelectric composite sensors.
Evolution of magnetic Kubo number of stochastic magnetic fields during the edge pedestal collapse simulation
