Research on Characteristic Stress and Constitutive Equation of Confined Sandstone during Damage Evolution Based on Energy Evolution Analysis

Table 2

Fitting function and parameters of DE proportion.

Confining stress (MPa)	Fitting function and parameters
	5	0.7	0.42	0.75	0.35
	10	0.63	0.43	0.75	0.37
20	0.64	0.43	0.8	0.46
30	0.62	0.42	0.9	0.5