Fracture Characteristics and Geometric Fractal of Damaged Sandstone under Impact Load

Table 1

Wave velocity change table before and after sandstone is subjected to cyclic loading.

(%)	Initial wave velocity	Wave velocity after damaged	Damage factor	Average damage factor
20	3201.5206	3168.1111	0.020762	0.020691
	3221.5006	3189.7009	0.019645
	3213.2865	3178.2879	0.021665
40	3226.9230	3081.7120	0.087975	0.087022
	3307.9461	3164.8239	0.084660
	3266.3903	3118.6236	0.088431
60	3291.5206	2861.3674	0.244292	0.250664
	3284.1357	2828.5371	0.258209
	3304.1666	2862.4621	0.249491
80	3373.4693	2207.7871	0.571687	0.562000
	3275.5102	2196.6878	0.550242
	3214.8384	2122.5974	0.564070