Simulation analysis of the influence of gangue layer morphology on the cutting characteristics of the roadheader bolter

In the actual excavation process of the roadway, besides the coal seam, there are various types of gangue layers on the working face. The existence of these gangue layers will affect the cutting efficiency of the roadheader bolter. However, most current studies analyze the cutting characteristics of the drum with the background of a fully-coal working face or consider a relatively simple morphology of the gangue layer. To solve the above problems, taking the MB670-1 roadheader bolter as the research object, a 3D model of the roadheader bolter is created using Pro/E software. The model is input into RecurDyn software and the corresponding motion pair is added. The model is then input into EDEM software to establish an EDEM-RecurDyn coupling simulation model. The influence of three types of gangue layers, horizontal gangue layers, inclined gangue layers, and semi-gangue layers, on the cutting characteristics of the roadheader bolter is simulated and analyzed from three aspects: drum cutting performance, drum displacement and drum vibration. The results show the following points. ① Compared with the full coal seam, under the conditions of gangue layers, the drum cutting resistance, load fluctuation coefficient, and cutting specific energy consumption all increase. They increase most significantly under the condition of inclined rock layers. The average cutting resistance increases by 35.61%. The load fluctuation coefficients along the X-axis (along excavation direction of the roadheader bolter), Y-axis (perpendicular to the roadway bottom direction), and Z-axis (parallel to the drum axis direction) increase by 26.79%, 25.39%, and 61.28% respectively. The cutting specific energy consumption increases by 37.21%. ② The existence of gangue layers causes a decrease in the displacement of the drum. Compared with the full-coal seam, the displacement of the drum is reduced by 53, 89, 14 mm in the horizontal gangue layer, inclined gangue layer, and gangue layer respectively. ③ The vibration amplitude generated by the drum when cutting a working face containing gangue is much greater than when cutting a working face containing full-coal seams. ④ The influence of the morphology of the gangue layer on the cutting characteristics of the roadheader bolter is in the order of inclined gangue layer ＞ horizontal gangue layer ＞ semi-gangue layer.