Numerical Simulation Research On Damage Of Rock Strength Caused By Microwave Irradiation

The main method of rock excavation has blasting and mechanical, two methods havesome shortcomings, the former large disturbance of the original rock, difficulties chambersupport, the latter high the first investment and short tool life, high cost and so on,sothe engineers hope to find an efficient rock breaking method. Researches show that, The rockstrength can greatly reduce by microwave irradiate, to help to improve the efficiency ofmechanical crushing rocks, so "Microwave and Mechanical" is expected to become effectivemethod of rock crushing, helping achieve low noise and low dust in rock crushing process.The purpose of this paper is to weaken the strength of the rock under microwaveirradiation, by changing the microwave power, irradiation time, types of rocks and otherfactors, study the law of rock strength weakening cause microwave radiation, analyzing of thereasons for the change rock strength under microwave irradiation by performing numericalsimulation and actual microwave irradiation test. Specific research and the results achievedare as follows:(1) Discussion of microwave irradiation damage on the principles of rock strengthcombined knowledge of microwave. Rock temperatures cause microwave radiation, makingthe internal stress of rock increases, stress distribution change and affect rock strength, rockstrength weakening cause by microwave radiation power, microwave irradiation time, rocktypes,(structure and mineral composition).(2) By using numerical simulation software to establish internal fissure and mineralparticle simulation model of rock specimen, get the situation under microwave irradiationstress cracks around the internal and mineral particles. Rock internal stress distribution ofcracks under microwave irradiation, crack tip appears obvious stress concentration, the stressconcentration, the more obvious with the increase of power and irradiation time.(3) In the microwave irradiation test, get various rock strength injury under differentcircumstances by changing the irradiation factor:The greater the power, the longer time, the more obvious damage to the rock strength, the different sensitivity of rocks in microwaveirradiation of different factors, for example, Granite and Limestone are more sensitive tochanges in irradiation time, the Sandstone of Northern Shaanxi sensitive to changes in themicrowave power.