Table 1.

Properties for the test specimen.

Materials	Parameters	Values	Unit
Steel plate	Dimension	20 × 20 × 0.6	cm
	Young’s modulus	206	GPa
	Density	7.9	g/cm3
	Poisson’s ratio	0.25	-
Rubber layer	Dimension	20 × 20 × 0.5	cm
	Young’s modulus	0.0078	GPa
	Density	1.27	g/cm3
	Poisson’s ratio	0.47	-
PZT-transducer	Dimension	φ18 × 3	mm
	Piezoelectric strain coefficients	2450	pC/N