Natural Frequency of Coal: Mathematical Model, Test, and Analysis on Influencing Factors

Table 3

Mechanical parameters of dried and saturated lignite coal samples.

State of coal sample	Elasticity modulus (GPa)	Poisson’s ratio	Uniaxial compressive strength (MPa)
Dried	1.11	0.30	9.36
Saturated	0.95	0.27	7.69