Experimental study on the influence of geometric parameters of prefabricated holes on the mechanical properties of rock-intruding disc cutters

YUAN Chao; HUANG Xuanqi; WANG Weijun; WAN Wen; WU Hai

doi:10.13247/j.cnki.jcumt.20240524

Abstract：In order to study the influence of the geometric parameters of the prefabricated hole on the mechanical properties of the rock-intruding disc cutter,the biaxial rock-intruding me-chanical tests of the disc cutter with different geometric parameters were carried out by using the method of indoor test and numerical simulation.The variation characteristics of the intru-sion force,the intrusion energy consumption and the intrusion difficulty coefficient with the hole arrangement,the hole angle and the hole depth were analyzed.The temporal and spatial evolution process of the crack was studied,and the mechanism of the crack propagation path induced by the prefabricated hole was revealed.The results show that compared with the com-plete specimen,the change of row spacing and hole spacing will significantly affect the rock in-trusion effect,and the effect of large row spacing(4,5 mm)and small hole spacing(1 mm)is significantly excellent.The maximum intrusion force,intrusion energy consumption and in-trusion difficulty coefficient of the specimen with holes decrease obviously with the decrease of angle.The greater the depth of the hole,the effect of reducing the maximum intrusion force is gradually weakened;the main crack evolution order of the specimen is shear crack → mixed crack → tensile crack.The prefabricated hole has a more obvious effect on guiding the crack propagation path,and the rock breaking process can be accelerated by optimizing the parame-ters of the prefabricated hole.When the prefabricated hole angle is large,the longer the crack propagates downward near the central axis;When the prefabricated hole angle is small,the crack can quickly expand to the bottom of the hole,so that the crack is limited between the holes,and the damage is more sufficient.The research results can provide technical support for pre-failure auxiliary disc cutter to invade rock and reduce cutterhead wear.