The piezoelectric polymer PVDF is characterized by the following piezoelectric constants: d31 = 23 × 10−12m/V, d33 = −33 × 10−12m/V, g31 = 216 × 10−3V/m/N/m2 , g31 = −330 × 10−3V/m/N/m2 , k55 = 0.012,...

The piezoelectric polymer PVDF is characterized by the following piezoelectric constants: d31 = 23 × 10−12m/V, d33 = −33 × 10−12m/V, g31 = 216 × 10−3V/m/N/m2 , g31 = −330 × 10−3V/m/N/m2 , k55 = 0.012, k33 = 0.014, and ε11 = 12 × ε0. The density of the material is ρ = 1780kg/m3 . The Young’s modulus for the material is E = 0.3 × 1010N/m2 . The ‘thin plate’ wave velocities in the longitudinal and transverse directions are 2200 and 1500 m/s, respectively. Determine the change in the SAW velocity due to piezoelectric stiffening. State all the relevant assumptions made in the analysis