Abstract: The chaotic motions of a large deflection thin rectangular plate simply supported at three sides in a coupling environment of mechanical load, magnetic field and temperature field is investigated. Based on the theory of plates and shells and the magnetic elasticity, and considering the effect of temperature field, the nonlinear governing equations of the plate undergoing the coupled fields is derived first. And then the coupled nonlinear vibration equation is obtained by using Galerkins method. The chaotic motion conditions of the dynamic system under the meaning of Smale horseshoe transformation is obtained using Melnikov function method. The numerical simulations about the vibration equation of the system are also presented. The bifurcation diagram, the displacement wave diagram, the phase diagram and the Poincare section diagram of this system are shown here. The influences of the parameters variation of mechanical load, magnetic field and temperature field to the chaotic motion of this system are discussed. From the simulation, the vibration characters of this system can be controlled by changing the parameters of mechanical load, magnetic field and temperature field.

Key words: Bifurcation, Chaos, Large deflection, Melnikov function method, Thermal-magneto elasticity