Abstract:This paper established an equivalent stiffness model for a clip spring structure, which was usually applied in a kind of piezoelectric vibration energy harvesters, mainly based on Mohr’s method. The accuracy of the model was validated by the universal tensile testing machine. Two ways to linearity simplify the stiffness of clamp springs were discussed: through fitting the tension curve and modifying the stiffness according to the resonant frequency. The research results showed that it was reasonable to consider it as a linear spring from the tension curve; while in the practical vibration energy harvesters, the stiffness of the clamp spring could be linearly modified according to the natural frequency of the oscillating system, the calculated amplitude-frequency response characteristics were similar to those of the nonlinear dynamic model. The research results provide theoretical support for the establishment of a simplified dynamic and electromechanical coupling models in the field of piezoelectric vibration energy harvesters.