Analysis of Roadheader for Breaking Rock Containing Holes under Confining Pressures

Liu, Zenghui; Du, Chenglie; Jiang, Haifeng; Li, Kai

doi:10.3390/en10081154

Cited by 16 publications

(6 citation statements)

References 32 publications

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“…After similar derivation, it indicates that the motion differential equations of the roll angle during horizontal and vertical cutting process also have the same form, as shown in Eq. ( 10), but the motion ( 7) Equations (9)(10)(11) are the dynamical model of roadheader's attitude.…”

Section: Dynamical Model Of the Attitudementioning

confidence: 99%

“…Consequently, the actual load on the cutting head is continuously varying, during cutting process of roadheader [6,7]. Besides, the geological conditions of the fully mechanized excavation face in steep coal seam is extremely complex [8,9], and the physical structure of roadheader itself is quite complicated. To be specific, the dip angle of coal seam and swing angle of roadheader's cutting arm will influence the operating status of roadheader.…”

Section: Introductionmentioning

confidence: 99%

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Modeling and response analysis of the attitude angles of roadheader for steep coal seam

Zong

2021

SN Appl. Sci.

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This study presents a dynamical model of the attitude angles of boom-type roadheader, to reveal the response characteristics of the attitude angles in steep coal seam. Based on the Lagrange equation, the dynamical model of the attitude angles of roadheader is established, then the simulation system is constructed in Simulink, to solve the dynamical model. Afterwards, a calculating method of the cutting load is proposed, to formulate the external loads of the roadheader during cutting process. Focused on the steep coal seam, of which the dip angle is 30°, the dynamical model is solved, and the solving results influenced by different factors are obtained. The results show that, the variations of roadheader's attitude are affected greatly by the cutting load, while the influence of swing angle of the cutting arm is relatively slight. Among the three attitude angles, the pitch angle varies most greatly, which can reach up to 9.1° and 8.7° during horizontal and vertical cutting process respectively. Finally, the numerical simulation results are verified by experimental data. The dynamical model and response characteristics of roadheader's attitude angle presented in this paper, can provide useful basis for prediction of roadheader's operating status and rectification of roadheader's attitude in steep coal seam. Article Highlights1. The dynamical model of roadheader's attitude is established, to accurately describe dynamic behaviors of roadheader during cutting process.2. The response regularities of roadheader's attitude in steep coal seam, under effects of different factors, are revealed comprehensively. 3. A method to calculate the cutting load is proposed, upon which the three dimension forces on the cutting head can be obtained.

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Section: Dynamical Model Of the Attitudementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Modeling and response analysis of the attitude angles of roadheader for steep coal seam

Zong

2021

SN Appl. Sci.

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show abstract

“…Among them, quartz accounted for about 50% of the total composition, which occurred as an irregular granular form with flaws. The modified SHPB experiment apparatus was adopted in this study, and the details have been described in our previous studies [23][24][25]. The wavelength of the incident wave was about 72 mm, and wave period was about 240 μs.…”

Section: Materials Identification and Experimental Programmentioning

confidence: 99%

Fracture Evaluation and Dynamic Stress Concentration of Granite Specimens Containing Elliptic Cavity under Dynamic Loading

Tao

Peng

et al. 2019

Energies

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The Split-Hopkinson pressure bar (SHPB) was used to determine the fracture characteristics of a long bar rock specimen with an elliptical cavity under different axial ratios and dip angles. A high speed camera was applied to record the fracturing process of the granite specimen around the cavity. The experimental results showed that the fracture characteristics around the elliptical cavity were closely related to the axial ratio and dip angle. A three-dimensional numerical model was established using LS-DYNA to quantitatively analyze the dynamic stress state around the cavity. The numerical results indicate that the dip angle and axial ratio of the elliptical cavity significantly affected the dynamic stress concentration factor (DSCF), then affected the rock failure. The location of higher DSCF led to a higher possibility of spalling failure. The maximum DSCF remarkably decreased with a decreasing dip angle and increased the axial ratio. In the dynamic loading propagate process, the stress concentration distribution around the cavity formed by a compression stress wave had a certain damaging effect on the destruction of rock around the cavity, and the stress concentration generated by the tensile stress wave was the main factor of the rock fracture, which was most notable in the peak area of the stress concentration.

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“…Due to the complexity and changeableness of the occurrence condition and physical mechanical properties of coal and rock in roadway cross-section, the hardness of coal and rock during cutting process is changing constantly and randomly; therefore the cutting head load is also continuously changing during the cutting process [7][8][9][10][11][12]. The complex and changeable cutting head load, different dip angles of coal seam, and constantly changing horizontal swing angle of cutting arm cause constant change of roadheader's body pose during the horizontal cutting process, which seriously influences the positioning and orienting excavation of the roadheader and leads to reduction in forming quality and drivage efficiency of the roadway [13][14][15][16]. Therefore, study on the regularities of roadheader's body pose responses during the horizontal cutting process has great significance in improvement of forming quality and drivage efficiency of the roadway, realization of robotized automatic cutting, and ultimately realization of "unmanned" operation in the fully mechanized excavation face.…”

Section: Introductionmentioning

confidence: 99%

Multifactor Analysis of Roadheader’s Body Pose Responses during the Horizontal Cutting Process

Zong

Zhang

Wang

et al. 2018

Shock and Vibration

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Based on the Lagrange equation in system dynamics, aiming at the horizontal cutting process, the dynamical coupling model of boom-type roadheader’s body pose was established. According to input problem of solving the model, a calculation method of the cutting head load was proposed, and the relationship between the cutting head load and pressure of the driving cylinders and swing angle of the cutting arm was obtained through simulating analysis. The simulation model was established to solve the dynamical coupling model. The cutting head load, horizontal swing angle of the cutting arm, and dip angle of coal seam were regarded as independent variables to perform changing parameter analysis in variations of the body pose. The field experiment was carried out, and the measured data is basically consistent with the simulation values. The results show that lateral displacement of the body can reach up to 6.5 cm, backward displacement can reach up to 5.2 cm, floor-based quantity can reach up to 11 cm, pitch angle of the body can reach up to 7.8°, and roll angle can reach up to 2.1°. Variations of the body pose parameters are influenced greatly by the cutting head load, while the influence from horizontal swing angle of the cutting arm and dip angle of coal seam is slighter. Among the pose parameters, floor-based quantity and pitch angle of the body vary relatively greatly, which tend to seriously influence forming quality of the roadway and should be mainly considered in deviation rectification of the roadheader’s body pose.

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Analysis of Roadheader for Breaking Rock Containing Holes under Confining Pressures

Cited by 16 publications

References 32 publications

Modeling and response analysis of the attitude angles of roadheader for steep coal seam

Modeling and response analysis of the attitude angles of roadheader for steep coal seam

Fracture Evaluation and Dynamic Stress Concentration of Granite Specimens Containing Elliptic Cavity under Dynamic Loading

Multifactor Analysis of Roadheader’s Body Pose Responses during the Horizontal Cutting Process

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