Experimental Research On Characterislics Of Coal Impact Damage Dynamics And Magnetic Field

The dynamic and magnetic-field characteristics in the process of coal impactdamage were studied through the combined method of experimental research,theoretical analysis, numerical simulation and field test. Using split Hopkinsonpressure bar (SHPB) and transient ZDKT-1type magnetic vibration test system,Dynamic characteristics and magnetic field changes in the destruction process of thecoal sample under different impact speeds were discussed,, besides, the relationshipbetween kinetics parameters such as strain rate and stress extreme values and thesignal amplitude and energy of magnetic field changes was studied; This paper fullyretained transient non-stationary characteristics of dynamic testing signals to identifythe main magnetic signal frequency-band when denoising with HHT; Combining thedamage model and the viscoelastic model, the coal impact damage injury body-viscoelastic constitutive model was established. HJC constitutive model was used todeal with coal sample and using LS-DYNA numerical simulation reproduces SHPBprocess of the coal impact damage. In this paper A coal shock-resistance measurementmethod was proposed, the law of energy dissipation in the impact failure process ofcoal was analyzes, and the energy evaluation model of coal and gas outburst wasestablished by using new theory of surface and the law of thermodynamics; Field testof blasting excavating power phenomenon shows that the change of the magneticfield signal energy has good response to coal power disasters.