Time-Frequency Characteristics and the Influence Mechanism of the EMR from Coal with Different Joint Angles

Table 1

Size and mechanical parameters of samples.

α (°)	Samples	Diameter (mm)	Height (mm)	Peak load (kN)	Failure time (s)	Postpeak failure time (s)
0	C-0-1	49.64	100.28	41.20	250	62.981
	C-0-2	49.72	100.08	48.28	280	43.333
	C-0-3	49.74	100.26	46.59	255	56.766
15	C-15-1	49.74	100.16	23.24	255	30.435
	C-15-2	49.76	100.20	27.24	190	18.118
	C-15-3	49.76	100.29	27.15	210	25.176
30	C-30-1	49.86	100.20	27.18	155	7.052
	C-30-2	49.76	100.28	41.57	185	6.265
	C-30-3	49.78	100.32	27.45	125	4.561
45	C-45-1	49.82	100.16	39.34	180	2.220
	C-45-2	49.72	100.40	41.96	190	4.493
	C-45-3	49.72	100.26	39.24	185	3.316
60	C-60-1	49.74	100.48	70.00	325	0.060
	C-60-2	49.72	100.18	73.45	360	0.085
	C-60-3	49.8	100.20	70.73	295	0.116
75	C-75-1	49.78	100.12	64.58	400	0.104
	C-75-2	49.74	100.20	81.30	440	0.090
	C-75-3	49.78	100.16	73.51	440	0.088
90	C-90-1	49.78	100.18	68.00	355	2.064
	C-90-2	49.74	100.24	67.16	360	3.041
	C-90-3	49.78	100.14	81.18	380	3.820