Method and system for detecting longitudinal piezoelectric strain constant d33 based on quasi-static method

The invention discloses a method and a system for detecting a longitudinal piezoelectric strain constant d33 based on a quasi-static method. The method comprises the following steps: applying a static force to a to-be-tested sample to stably clamp the sample; variable-frequency quasi-static force is applied to the sample in the stable state, and the frequency of the quasi-static force is smaller than the resonant frequency of the sample; measuring the electric charge quantity generated by the sample corresponding to the quasi-static force, namely a piezoelectric signal; and obtaining the d33 constant of the sample according to the piezoelectric signal and the quasi-static force signal. According to the application, the quasi-static force is applied to the sample, the charge quantity at the two ends of the sample is measured, the d33 constant of the sample is obtained according to the charge quantity and the quasi-static force signal, and the quasi-static force is adjusted to make the quasi-static force more a