Abstract: The effects of modification on the nonlinear dynamic characteristics are analyzed. The accurate mesh stiffness and static transmission error are calculated by using finite element method. The mesh stiffness and static transmission error are introduced in the nonlinear dynamic gear transmission system directly. And the general Fourier series is not adopted to approximate the mesh stiffness and static transmission error in order to avoid confusion between the modification and approximate error. The vibration amplitude and dynamic factor are proposed to indicate the effects of modification on the gear nonlinear dynamics characteristics. The numerical results show that the proposed method can be used to discriminate the effect of modification; the dynamic analysis based on nonlinear system with backlash and modification can provide comprehensive understanding on the transmission characteristic; the effects of modification are analyzed in a broadband rotation speed, which are helpful to determine the modification length and amplitude.

Key words: gear;modification;dynamic factor;mesh stiffness;transmission error