Burst Failure Characteristics and Energy Evolution Law of Coal with Prefabricated Cracks at Different Angles

Table 3

Dynamic failure time of coal under different crack angles.

Specimen types	Group a (ms)	Group b (ms)	Group c (ms)	Average value (ms)
Complete cylinder	2500	1250	2183	1977
0° cracked cylinder	8438	7188	6875	7500
30° cracked cylinder	6562	6563	6845	6656
60° cracked cylinder	3750	6249	6120	5373
90° cracked cylinder	1563	3749	1563	2291