In this paper, nonlinear resonance characteristics of a dielectric elastomer actuator are investigated with special consideration on the thermal effects. A finite thermo-elasticity model based on the Gent model is constructed to analyze the vibrational response of the system. The equation of motion is derived via the Euler–Lagrange method. The multiple scales method and the Taylor series expansion are used to solve the governing equation. Nonlinear resonant responses of the system such softening/hardening and jump are explored. Furthermore, the influences of different system parameters including temperature, limiting stretch, damping, mechanical load, relative permittivity and voltage on the frequency response curves are explored. The results are compared with those obtained in the isothermal state, and those solved by numerical methods. It is found that both softening and hardening-type nonlinearities occur in the system in both non-thermal and thermal conditions.
