Effect of piezoelectric constants on mechanical properties of PFC

Piezoelectric actuators offered many advantages including quick response, high-induced stress, low energy consumption and low cost, which made them very attractive for a number of applications. However, some disadvantages, especially the low induced displacement and the typical isotropic laminate layers, deeply limit their applications requiring off-axis or twisting motions. Piezoelectric Fiber Composites are one of the new type piezoelectric devices for actuators, since it has obvious anisotropy as well as high toughness that couldn´t be gotten from normal piezoelectric actuators. Piezoelectric Fiber Composites are denominated by piezoelectric fiber, polymer and interdigitated electrode layer. In order to improve the performance of Piezoelectric Fiber Composites, two piezoelectric unit´s construct functions about longitudinal length extension vibration mode are established. According to the construct functions for piezoelectric actuator, some finite models are established. Then the mechanical properties are analyzed in detail. The anisotropy is characterized. ANSYS is employed to numerically research the influence of piezoelectric constants on the Piezoelectric Fiber Composites´ stress. Several rules are summed. The results show much high stress can be obtained by increasing elastic modulus E₃, Poisson´s ratio μ₁₂, μ₁₃, or decreasing elastic modulus E₁, shear modulus G₁₃, dielectric coefficient ε₁₁, ε₃₃.