Question: A circular piezoelectric plate with diameter d = 20 mm, thickness h = 3 mm, Young's modulus of 1.7 # 1011 N/m2 , mass density of 7,00 kg/m3 , and dm = 3 # 10-11 m/V is attached at the midpoint of a bridge, as shown in Figure. A displacement u = 0.008d(t) m is provided to the bridge externally with d(t) being the unit impulse. Determine and plot the sensing voltage variation with time. Known are the bridge data: length of 180 mm, width of 20 mm, thickness of 2 mm, Young's modulus of 2.1 # 1011 N/m2 , mass density of 7800 kg/m3 . The piezoelectric losses are equivalent to a viscous damping coefficient c = 12 N-s/m.
