Experimental Study on the Boundary Reflection Effect of Stress Wave Propagation Based on the Newly Developed Test Apparatus

Table 3

The measured wave impedance values of boundary materials.

Materials	Size (mm)	Wave speed (m/s)	Density (kg/m^3)	Wave impedance (10^6 kg/m^2·s)
1# pine pad	120 × 120 × 100	5,630.02	588.80	3.31
2# pine pad	120 × 120 × 100	5,537.55	601.37	3.33
3# pine pad	120 × 120 × 80	5,075.34	435.80	2.21
4# pine pad	120 × 120 × 80	4,161.74	455.18	1.89
Rubber pad	120 × 120 × 10	235	1,490	0.35
Steel pad	120 × 120 × 10	5,200	7,900	41.08