Modeling of humidity effect on electromechanical properties of viscoelastic dielectric elastomer

•The dependency relationship between the parameters of DE and the relative humidity are obtained by fitting presupposed models to the experimental data.•The humidity effect on static and dynamic electromechanical performances is explored.•Phase paths and Poincaré maps are utilized to detect the humidity effect on the stability and periodicity of the nonlinear vibration.•The variation tendency of resonant frequency is investigated by continuously varying the relative humidity.