Abstract: The three-dimensional nonlinear distribution of the magnetic field is studied by using Maxwell equations. The nonlinear magneto-mechanical coupled model is obtained by coupling the nonlinear constitutive model of Galfenol alloy with the structural beam model. The coupled model is implemented in weak form equations. Simulations show that the maximum value of flux density shows up close to the fix end. The strain of the cantilever beam has a similar distribution as the flux density. Experimental researches are conducted by using nonperiodic step signal and periodic sinusoid signal, respectively. It is shown that the calculation results from the model are in good agreement with the experimental data. The proposed model can predict the dead zone, the linear region and the saturation region of the experimental data accurately. Also, it is shown that there are small drifts in the step response of the composite beam due to the existence of sub-harmonic disturbance. It can be seen from the model response that the proposed model can predict the drifts in step response as well.

Key words: Anisotropy, Cantilever beam, Galfneol alloy, Nonlinear coupling, Three-dimensional model