Study On The Influence Of Impact Load On The Microcrystalline Structure Parameters Of Anthracite

In order to study the change of microcrystalline structure under the impact load of different directions and different sizes of anthracite coal,this paper takes the anthracite coal of the second coal seam of Shanxi Formation in Zhaogu No.2 Mine of Henan Province as the research object,and uses the Hopkinson Impact Test System（SHPB）Five types of impact tests were carried out on coal samples taken from the vertical,parallel and oblique directions in the direction of bedding.X-ray diffraction（XRD）technology was used to analyze and compare the microcrystalline structure changes of the raw coal and the coal samples after impact.The main conclusions are as follows:（1）The static compression test of coal samples with parallel bedding direction,vertical bedding direction and skewed to bedding is completed.The test results show that the vertical stratified coal sample has the highest compressive strength,and the skewed bedding coal sample has compressive strength lowest,the mechanical parameters of coal samples perpendicular to the bedding direction are greater than those parallel to the bedding direction.（2）The research and analysis of coal sample failure forms under different impact loads show that:（1）When the impact load is small,the coal sample damage degree is small,the coal sample cracks along the axial direction,there are many large-size fragments,and the coal sample breaks Tensile stress is dominant.（2）With the increase of impact load,the degree of fragmentation of the sample deepened,and small-sized fragments increased significantly,and the failure was mainly due to compression and shear stress.（3）The grid spacing d₀₀₂of the microcrystalline structure of coal changes with the increase of impact load,and the change trend has two obvious stages:a rapid decline stage and a gentle decline stage.The degree of stacking（Lc）in the microcrystalline structure of coal shows an increasing trend with increasing impact load.When the impact load reaches 139.5 MPa,the vertical bedding coal sample Lc increases by 1.641?compared with the original coal Lc parameter The interbedded coal sample Lc increased by 1.424?,and the parallel bedding coal sample Lc had a minimum change of 1.24?.Under the same impact load,the microcrystal structure of the coal sample taken perpendicular to the bedding changed the most.（4）Under the impact of explosion impact,the change law of microcrystalline structure parameters of coal samples in three directions is basically similar,indicating that under the strong impact load,the change of microcrystalline structure parameters is not affected by the direction of coal sample bedding.