This paper presents the dynamic analytical solution of a piezoelectric stack utilized in an actuator and a generator based on the linear piezo-elasticity theory.The solutions for two different kinds of piezoelectric stacks under external load were obtained using the displacement method.The effects of load frequency and load amplitude on the dynamic Accessories characteristics of the stacks were discussed.The analytical solutions were validated using WHEY PROTEIN CARAMEL CHOCOLATE the available experimental results in special cases.The proposed model is able not only to predict the output properties of the devices, but also to reflect the inner electrical and mechanical components, which is helpful for designing piezoelectric actuators and generators in a comprehensive manner.