Mechanical Properties of Bump-Prone Coal with Different Porosities and Its Acoustic Emission-Charge Induction Characteristics under Uniaxial Compression

Figure 21

Test result of AE energy and charge accumulations for coal specimen under uniaxial compression in different stages. (a) Strengthening stage before peak; (b) peak point; (c) after peak. Stress is denoted by the black curve, AE energy accumulation by the blue curve, and charge accumulation by the thin pink line.

(a)

(b)

(c)