斜角及其对岩石切割性能的影响外文文献翻译、中英文翻译、外文翻译.doc
斜角及其对岩石切割性能的影响外文文献翻译、中英文翻译、外文翻译
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Research Article Slant Angle and Its Influence on Rock Cutting PerformanceYong Sun and Xingsheng Li CSIRO Energy, P.O. Box 883, Kenmore, QLD 4069, Australia Correspondence should be addressed to Yong Sun; yong.suncsiro.au Received 21 February 2018; Accepted 23 April 2018; Published 13 June 2018 Academic Editor: Hang Lin Copyright 2018 Yong Sun and Xingsheng Li. ( is an open access article distributed under the Creative Commons Attribution License, which ppermits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.Rock cutting is an important aspect of the civil engineering, for example, tunnelling. To improve cutting efficiency, it is important to understand the rock failure (fracture) mechanisms and the influences of cutting parameters on rock fracture behaviour. (is study identified that the relative position of a pick (rock cutting tool) to the rock surface is critical to the cutting performance of the pick during rock cutting process. However, the pick tilt angle commonly used by the industries is not sufficient to describe this relative position. To address this issue, a new angle named “slant angle” is introduced. (e slant angle of a pick is determined by its tilt angle and the inclination angle of the rock surface. (e calculation of the slant angle is presented. A series of laboratory rock cutting experiments were conducted to investigate the influence of the slant angle on cutting force and rock fracture pattern, and two new findings were made: (1) the rotational angle of the groove cut by a tilted pick was possibly different from the tilt angle and (2) all forces on a pick increased significantly with the increase of the slant angle. (e findings of this study can help improve the rock cutting efficiency.1. IntroductionRock cutting plays an important role in the civil engineering which involves construction of tunnels 1 and road development 2. Rock cutting performance is a major concern to the mining and construction industry 3. Understanding rock fracture (breaking) behaviour under different cutting conditions is crucial for enhancing the cutting performance of excavating machines. Studies on rock failure mechanism have been used to analyse the rock cutting process 4, 5, although many studies on rock failures aimed at increasing the safety of the rock structure (e.g., see 6). Two major factors considered in the analysis and evaluation of the cutting performance are forces acting on picks (a type of typically used rock cutting tool in the mining and construction industry) and rock fracture (breakout) conditions. Pick forces were often investigated by rock cutting tests 3, 7. A pioneer work for developing a theoretical cutting force model was done by Evans 8. Many factors can affect the forces acting on a pick and rock fracture condition cut by this pick, including rock characteristics such as rock compressive strength, tensile strength, and rock fracture behaviour; pick characteristicssuch as pick tip material properties and geometry; operational characteristics such as drum advance speed and drum rotational speed; frictional coefficient between pick cutting tip and rock surface; and cutting interaction between this pick and other picks 913. Existing studies have largely focused on the effect of the attack angle, tilt angle, rake angle, and clearance angle on the cutting performance of a drum and the influence of the angle setting sequence on the final values of tilt and attack angles 14. The rock fracture conditions (mainly breakout angle and direction) and the forces acting on a pick can be affected by the position of a pick relative to the rock surface, not only in the cutting plane but also in the normal plane. Cutting plane in this paper refers to a plane perpendicular to the rotational axis of the drum if the movement of the drum is parallel to this plane. Otherwise, this plane is the one formed by the instantaneous advance direction of the pick due to the drum advance movement and the instantaneous cutting direction of the pick due to the drum rotation. However, even in this case, as the influence of the drums movement on the picks cutting direction can generally be ignored, the cutting plane can also be treated as a plane perpendicular to the rotational axis of the drum. Normal plane in this paper refers to a plane containing the rotational axis of the drum and perpendicular to the pick cutting direction. Note that, for a particular pick, the positions of these two planes to its drum can be xed by making them to contain the tip of the pick, but their positions relative to the rock being cut during a cutting process will still change with the rotation and movement of the drum. Obviously, the cutting planes and normal planes of individual picks on a drum are not all the same. Furthermore, the cutting direction of a pick rotates during a cutting process, resulting in the rotation of its cutting plane and normal plane. e gesture of the pick and its position relative to the rock surface can inuence the breakout shape, force direction, and magnitude, as well as the cutting interaction. Currently, various angles have been used to describe the relative positions of picks to their drum and rock surface cut by them and/or evaluate their individual and collective cutting performance, including the attack angle, clearance angle, rake angle, tilt angle, and wrap angle. Attack and tilt angles are dened in two orthogonal planes to determine the position of the pick axis 12. Although their denitions are based on the cutting direction, they do not depend on the rock surface. On the other hand, clearance angle and rake angle are dened based on the tip prole and the rock surface in the cutting plane. e wrap angle is used to determine the arrangement of picks on the drum and not associated with the rock surface. Another angle used is the inclination angle, which depends on the wrap angle, but it is dened on the rock surface after cut 10. e inclination angle is also related to the tilt angle. More details about the inclination angle are given in the next section. Studies have revealed that the attack angle is a major factor aecting the forces acting on a pick 15. Both tilt angle and inclination angle will also aect the force acting on a pick 10, 16, 17. In the course of rock cutting with a drum, the positions of picks relative to the rock surface play an important role in the forces acting on the picks and rock breakout conditions. Forces acting on a pick and the rock breakout angle generated by this pick can be aected by this picks relative position to the rock surface, not only in its cutting plane but also in its normal plane. Although changing the attack angle of a pick changes its relative position to the rock surface in the cutting plane, changing the tilt angle of a pick mainly changes its relative position in the normal plane. However, the tilt angle cannot solely determine this relative position because it is measured based on the drum axis rather than the rock surface, which does not have a xed relationship with the drum axis. To address the issue that there is not any parameter to dene the relative position of a pick to the rock surface in the normal plane, a new parameter named “slant angle” is proposed and discussed in this paper. A series of laboratory rock cutting experiments were conducted to investigate the inuence of the slant angle and the tilt angle on the rock breaking (fracture) behaviour in terms of rock breaking out angle, groove shape, and direction, as well as the forces on the cutting tools. No similar experiments have been reported in existing literature.2. Concepts of Tilt Angle, Inclination Angle, and Slant AngleTilt angle, inclination angle, and slant angle, which are the focus of this study, are all dened in the normal plane.2.1. Tilt Angle. Tilt angle is one of the key parameters that determine the location and gesture of a pick on a drum. It has been well dened and widely used in the drum design. According to Sun and Li 9, the tilt angle of a pick is typically dened as the angle between its cutting plane and the projection of the axis of the pick on its normal plane, as shown in Figure 1.As one of the key pick arrangement design parameters, the tilt angle plays a critical role in the cutting performance of picks and drum. Research has shown that the tilt angle has a noticeable impact on the force acting on a cutterhead (drum) 16.e experimental studies reported by Hekimouglu recently 17 revealed that the tilt angle of picks on roadheaders has an optimal value, which was roughly the half of rock breakout angle for corner cutting picks. 2.2. Inclination Angle. While the tilt angle is dened relatively to the drum, the inclination angle is dened based on the rock surface that has been cut by the drum. According to Hekimoglu and Ozdemir 10, the inclination angle is de- ned as the angle of the slope of a cutting perimeter which is an envelope formed by the tips of picks in the same start on the same normal plane 10 (refer to Figure 2). Figure 2 shows a simulated rock breakout pattern for a simulated drum design. According to Hekimoglu and Ozdemir 10, the perimeter is a sloping straight line if these picks areevenly distributed and their tilt angles are zero, as shown in Figure 2. e inclination angle is actually the angle between a cutting perimeter and the rotational axis of the drum on a normal plane. Obviously, the inclination angle could change with the rotation of the drum. In the following analysis, the inclination angle on the normal plane which is parallel to the drum advance direction (i.e., the breakout plane as dened in 12) is considered because rock breakout pattern is dened in this plane 12. Furthermore, the following formula to calculate an inclination angle given by Hekimoglu and Ozdemir in 10 is also based on this plane:where I is the inclination angle, is the angular distance between two immediate neighbouring picks, S is the line spacing between these two picks, vn is the advance per revolution of the drum, and m is the number of starts.The maximum depth of cut (DOC) Dmax is given by 11Equation (1) can be rewritten asEquation (1) indicates that the inclination angle increases with the increase in drum advance distance per revolution. It should be noted that (1) is used only for a special case: picks are evenly spaced without being tilted. e angular dierences among picks are equal, and the calculated inclination angle has the maximum value. It is notsuitable for calculating the inclination angle in other cases, for example, if picks are tilted. However, the analysis of the inclination angle in a general case will not be discussed further in this paper due to the scope of the paper. Some investigation into the eect of the inclination angle on the performance of picks has been carried out although the inuence of the tilt angle has not been considered; that is, existing studies on the eect of the inclination angle was conducted under the condition that the tilt angle was zero.2.3. Slant Angle. e slant angle of a pick is dened as the angle between the axis of the pick and the normal direction of the rock surface being cut by the pick (Figure 3).During a mining process with a cutting drum, the rock surface is normally curved. In this case, the slant angle is dened as the angle between the axis of the pick and the lineperpendicular to the cutting perimeter, measured in its normal plane (Figure 4). Figure 4 shows another simulated rock breakout pattern for the same simulated drum design as used for Figure 2, but with a dierent drum advance distance per revolution. As mentioned in the previous section, the inclination angle increases with an increase in drum advance distance per revolution, which can also be observed by comparing Figures 2 and 4. From Figure 4, it can be seen that the slant angle of a pick is equal to the inclination angle when its tilt angle is zero. In general, the slant angle of a pick isWhen using (4), one should ensure that the denitions of the directions of the inclination angle, tilt angle, and slant angle are the same. For example, if a positive inclination angle goes anticlockwise, both tilt and slant angles should also be measured anticlockwise. As shown in Figure 4, when I is negative, s is positive and is zero. Obviously, when I is zero, that is, rock surface being cut is parallel to the rotational axis of the drum, the slant angle of a pick is equal to its tilt angle. However, this is very rare in reality. e reason is that the angular distance between two immediate neighbouring picks in a real drum is normally not zero. According to (1), I is also generally nonzero (also refer to Figures 2 and 4). As a result, one can nd that the slant angle of a pick is generally not equal to its tilt angle in reality according to (4). is result is further illustrated in Figure 5. The above nding is important for optimising drum design and operation because in current practice, force on a pick is often obtained from some linear rock cutting experiments. In this type of cutting experiments, when the tiltangle of a pick is set to zero, its slant angle is also normally zero. As a consequence, using the force data collected in these experiments to drum design without consideration of the inuence of the slant angle can cause signicant bias in the estimation of actual forces on picks and the drum in practice. e reason is that the slant angle has signicant impact on forces and breakout pattern.3. Impact of the Slant AngleA series of rock cutting experiments have been conducted in CSIRO Rock Cutting Laboratory to investigate the rock breaking (fracture) behaviour in terms of rock breaking out angle, groove shape, and direction, as well as the forces on the cutting tools.3.1. Experimental Rig and Method. Figure 6 shows the experimental rig used in the tests. It is basically a planer, which consists of a special tool holder, a pick, a data acquisition system, and a rock block. A series of special cutting tool holders were purposely designed and manufactured to generate dierent combinations of tilt angles and attack angles. During each test, the rock block travelled against the pick in a controlled speed, and the dynamometer of the data acquisition system simultaneously measured three forces acting on the pick, namely, force in the X direction, force in the Y direction, and force in the Z direction. e measured forces were recorded by a LabVIEW system in a PC. e X, Y, and Z directions are dened based on the coordinate system, as shown in Figure 6: the X axis is horizontal and its positive direction is opposite to the cutting direction which is toward the front; the Y axis is horizontal and perpendicular to the cutting direction with its positive direction pointing to the left; the Z axis is perpendicular to the XY plane with its positive direction pointing upward. Further information about this planer and its data acquisition system can be found in 16. Test rock was a type of sandstone collected from Helidon, Australia, with UCS (uniaxial compressive strength) of 3740 MPa and BTS (Brazilian tensile strength) of 4.64.8 MPa. e slant angle was measured inside the YZ plane, starting from the Z-axis. Its positive direction is counterclockwise (Figure 6). In the experiment, the rock surface was trimmed to be a horizontal plane; that is, it was parallel to the XY plane. A linear rock cutting with a single pick was adopted in the cutting tests. In each cut, the track of the pick tip was parallel to the X-axis. In this case, the inclination angle of the rock surface was zero, and the slant angle was equal to the tilt angle of the pick As the major purpose of this paper is to dene the slant angle and test the hypothesis that the slant angle could signicantly affect rock cutting performance, only the test results under the conditions shown in Table 1 is considered in the paper. In Table 1, only the slant angle is a variable.At least three cuts were conducted for each slant angle. Note that, in the tests, the slant angles were actually set to 7.5 degrees and 15 degrees, rather than 7.5 degrees and 15 degrees. In order to obtain the forces for a positive slant angle from the test results obtained based on its corresponding negative slant angle, the following assumption is made:If only the direction of a slant angle is reversed, the forces in X and Z directions will remain the same, and the absolute value (magnitude) of the force in the Y direction will also be the same. Only the direction of the force in the Y direction will be reversed.Figure 8: Pick forces during the cutting tests with dierent slant angles: (a) 0 degrees, (b) 7.5 degrees, (c) 15 degrees, (d) 22.5 degrees, and (e) 30 degrees.is assumption is reasonable because the rock block was regarded as homogeneous.3.2. Test Results and Discussion. Figure 7 shows an example of grooves cut by a pick at dierent slant angles (the slant angle for cutting Groove 16 was dierent from that for cutting Grooves 17, 18, and 19). In this gure, Grooves 17, 18, and 19 were cut by the pick set to an attack angle of 60 degrees, a slant angle of 15 degrees, and the DOC of 12 mm. It can be seen that the grooves were skewed; that is, the bisector of any groove cross-sectional area is not perpendicular to the rock surface in the YZ plane. More importantly, the rock cutting experiments revealed that although the grooves were skewed when the pick was tilted, it is likely that the rotational angle of the bisector of the groove crosssectional area was not the same as the tilt angle. erefore, assuming that the rotational angle of the bisector of the groove cross-sectional area is equal to the tilt angle could result in unacceptable errors. However, the inuences of the slant angle on rock breaking shapes are not further studied here. e study on this type of inuences will be reported in a separate paper. In the following analysis, only the impact of the slant angle on the forces generated during a cutting process is investigated in more detail. e cutting tests revealed that the slant angle aected not only the rock breakout conditions but also the forces on the pick. Some examples of the planer displacement and the pick force data collected from the tests are shown in Figure 8. In Figure 8, blue continuous lines are the recorded forces and the pink broken lines are the mean values of the corresponding forces. As shown in Table 1, the rock cutting tests were carried out with ve dierent slant angles, and for each slant angle, the tests were repeated for three times to reduce the random errors in the test data. In total, 15 cutting experiments were implemented. Table 2 shows the test results. plemented. Table 2 shows the test results. e average values are used to identify the inuences of the slant angle on individual forces. Figure 9 illustrates the average mean forces in X, Y, and Z directions versus the slant angle. To make the gures clearer, the original mean force data are not plotted in these gures. Table 3 summarises the R-squared values when dierent models are applied to t the data in Figure 9. Figure 9 shows that all the mean forces increased with the increase of the slant angle, but none of them changed with the variation of the slant angle in a linear way. From Figure 9 and Table 3, it can be found that the quadratic models t the test results much better than the linear models. Within the tested range of the slant angles, the relationship between the forces and the slant angle can be modelled as follows:where, Fx, Fy, and Fz are the mean forces in X, Y, and Z directions, respectively.It is noted that, in pick force analysis, the forces acting on a pick during a cutting process are normally divided into cutting, normal, and lateral forces 2, 13. e cutting force is the force opposite to the cutting direction; the normal force is the force perpendicular to the cutting direction and inside the plane formed by the tangent line of the instantaneous cutting tract and the pick axis; and the lateral force is the force perpendicular to the plane formed by the cutting and normal forces 2. erefore, the cutting force on the pick is always identical to the force in theX direction. When the slant angle is zero, the force in the Y direction is the lateral force on the pick, and the force in the Z direction is the normal force on the pick. However, when the pick is tilted in a cutting process, the force in the Y direction no longer represents the lateral force, and the force in the Z direction no longer represents the normal force (see Figure 10). In general, the cutting, lateral, and normal forces on a pick can be calculated from the measured forces in X, Y and Z directions using the following equations:where, Fc, Fl , and Fn are the cutting, lateral, and normal forces on the pick, respectively. Figure 11 depicts the changes of mean lateral force and mean normal force with the change of the slant angle. From Figure 9(a), it can be seen that the cutting force acting on the pick increased signicantly with the increase of the slant angle because the cutting force was the same as the force in the X direction. Figure 9(a) indicates that with the increase of the slant angle from 0 degrees to 30 degrees, the cutting force increased from 5.9 kN to 9.7 kN. From Figure 11, it can be found that the magnitude of both the lateral force and the normal force on the pick also increased signicantly with the increase of the slant angle. When the slant angle increased from 0 degrees to 30 degrees, the lateral force increased from 0 kN to 5 kN, while the normal force increased from 5.6 kN to 10 kN. ese results indicate that slant angle had a signicant inuence on the force acting on a pick in a rock cutting process.4. ConclusionsA new angle named “slant angle” is introduced to determine the relative position of a pick to the rock surface to be cut in the normal plane of the pick. It is the angle between the axis of the pick and the normal direction of the rock surface; the slant angle depends on the tilt angle and inclination angle. It changes with the variation of drum advance per revolution. It is a better variable than the tilt angle for describing the relative position of a pick to the rock surface; laboratory rock cutting experiments were conducted to investigate the in- uence of the slant and tilt angles on cutting force and rock breakage (fracture) behaviour. e following major ndings were obtained from the experiments: (i) e rotational angle of the bisector of the groove cross-sectional area was likely to be dierent from the tilt or slant angle. Assuming that this rotational angle equals the tilt angle could result in unacceptable errors. (e magnitudes of the cutting, lateral, and normal forces on a pick all increased significantly with the increase of the slant angle. Assuming that the magnitudes of these forces are independent from the tilt or slant angle is unrealistic. Teseindings are important for the improvement of the rock cutting efficiency and rock cutting tool life. Only the slant angle on the normal plane parallel to the drum advance direction has been considered in this paper. (e slant angle in more general situations will be studied in due course.Data AvailabilityThe a used in this manuscript were generated during the study and can be found at the CSIRO Rock Cutting Laboratory, QCAT, Australia.Conflicts of Interest(e authors declare that there are no conflicts of interest regarding the publication of this article.Acknowledgments(e authors are grateful for the technical support of Craig Harbers of CSIRO Energy in the rock cutting experiments and the financial support of CSIRO Strategic Program.References1 T. Zhao, W. Liu, and Z. Ye, “Effective of water inrush from tunnel excavation face on the deformation and mechanical performance on shield tunnel segment joints,” Advances in Civil Engineering, vol. 2017, Article ID 5913640, 18 pages, 2017. 2 Y. Sun and X. S. Li, “A probabilistic approach for assessing failure risk of cutting tools in underground excavation,” Tunneling and Underground Space Technology, vol. 70, pp. 299308, 2017. 3 N. Bilgin, M. A. Demircin, H. Copur, C. Balci, H. Tuncdemir, and N. Akcin, “Dominant rock properties affecting the performance of conical picks and the comparison of some experimental and theoretical results,” International Journal of Rock Mechanics and Mining Sciences, vol. 43, no. 1, pp. 139 156, 2006. 4 H. Guo, “Rock cutting studies using fracture mechanics principle,” Ph.D.(esis, University of Wollongong, Wollongong, NSW, Australia, 1990. 5 Y. Nishimatsu, “(e mechanics of rock cutting,” International Journal of Rock Mechanics and Mining Sciences, vol. 9, no. 2, pp. 261270, 1972. 6 R. H. Cao, P. Cao, and H. Lin, “A kind of control technology for squeezing failure in deep roadways: a case study,” Geomatics, Natural Hazards and Risk, vol. 8, no. 2, pp. 17151729, 2017. 7 H. Copur, N. Bilgin, H. Tuncdemir, and C. 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Li, “Ineffective rock breaking and its impacts on pick failures,” in Proceedings of the 31st International Symposium on Automation and Robotics in Construction and Mining, pp. 754760, University of Technology, Sydney, Australia, July 2014. 12 Y. Sun, X. S. Li, and W. Shao, “Influence of cutting parameters and interactions on the depth of cut in continuous mining operation,” Advanced Materials Research, vol. 538541, pp. 14221428, 2012. 13 K. G. Hurt, C. J. Morris, and K. M. MacAndrew, “(e design and operation of boom tunneling machine cutting heads,” in Proceedings of the Rock Breaking and Mechanical Excavation: 14th Canadian Rock Mechanics Symposium, P. Baumgartner, Ed., pp. 5458, Vancouver, BC, Canada, May 1982. 14 Y. Sun and X. S. Li, “Impact of pick skew and tilt on cutting geometry,” Applied Mechanics and Materials, vol. 851, pp. 216220, 2016. 15 W. Shao, X. S. Li, Y. Sun, and H. Huang, “Parametric study of rock cutting with SMART CUT picks,” Tunnelling and Underground Space Technology, vol. 61, pp. 134144, 2017. 16 O. Z. Hekimoglu and R. J. Fowell, “Practical aspects of rear pick arrangement on boom-type tunnelling machine cutting heads,” Mining Science and Technology, vol. 10, no. 2, pp. 221230, 1990. 17 O. Z. Hekimoglu, “Investigations into tilt angles and order of cutting sequences for cutting head design of roadheaders,” Tunnelling and Underground Space Technology, vol. 76, pp. 160171, 2018.斜角及其对岩石切割性能的影响岩石切割是土木工程的一个重要方面，例如隧道施工。为了提高切削效率，这是很重要的了解岩石破坏(断裂)机理及切削参数对岩石断裂行为的影响。(是研究发现，镐(岩石切削工具)与岩石表面的相对位置对钻头的切削性能至关重要在岩石切割过程中截齿。然而，行业常用的截齿倾斜角不足以描述这一点相对位置。为了解决这个问题，引入了一种新的角度“斜角”。镐的倾斜角是由它的倾斜角度和岩石表面的倾斜角。给出了斜角的计算方法。一系列的实验室岩石进行了切削试验，研究了倾斜角度对切削力和岩石断裂形态的影响有两个新发现:(1)斜镐切割槽的旋转角度可能与倾斜角度不同(2)随着镐齿倾角的增大，镐齿所受的力显著增大。e这项研究的结果可以帮助改善岩石切削效率。1. 介绍岩石切割在土木工程中起着重要的作用包括建造1隧道和2道路发展。岩石切割性能是一个主要的关注矿业和建筑业3。理解不同切削条件下岩石的断裂(破坏)行为条件对提高切削性能至关重要挖掘机器。对岩石破坏机理的研究已经开始被用于分析岩石切割过程4,5，尽管许多关于岩石破坏的研究都是为了提高岩石的安全性岩石结构(例如，见6)。考虑了两个主要因素在对切削性能进行分析和评价时作用在镐上的力(一种典型的岩石切割方式)在采矿和建筑工业的工具)和岩石骨折(突破)条件。镐力通常通过岩石切割试验来研究3,7。为做先锋工作用有限元方法建立了切削力的理论模型埃文斯8。有许多因素可以影响作用在镐上的力以及用该镐切割的岩石的断裂情况，包括岩石岩石抗压强度、抗拉强度等特性强度和岩石断裂行为;拾取特性，如拾取尖端的材料性能和几何形状;操作滚筒前进速度、滚筒转速等特性;截齿之间的摩擦系数和岩石表面;切断这个镐之间的相互作用和其他选择9-13。现有的研究主要集中在对攻角、倾斜角、前倾角的影响间隙角对滚筒的切削性能有很大的影响角度设置顺序对最终值的影响倾斜和攻击角度14。一个镐的位置相对于岩石表面，不仅在切割平面也在法线平面上。剖切面本文指的是一个垂直于旋转的平面滚筒的轴线若与滚筒的运动平行这架飞机。否则，这个平面就是由由于滚筒的瞬时前进方向超前运动和瞬时切削方向因滚筒转动而引起的镐的转动。然而，即使这样如鼓的运动对镐的影响切割方向一般可以忽略，切割平面也可以看作是一个垂直于滚筒旋转轴的平面。本文中的法向平面指包含滚筒和旋转轴的平面垂直于截齿切割方向。注意,对一个特定的选择，这两个平面的位置鼓可以包含的顶端但是他们的位置与被切割的岩石有关在切削过程中仍会随旋转而改变还有鼓的运动。显然是切割平面鼓上单个鹤嘴锄的法线面并不是全部相同的。此外，还确定了镐的切削方向在切割过程中旋转，导致旋转它的切割面和法向面。选择的手势和它的位置相对于岩石表面能元代突破的形状、力量方向和幅度作为切割互动。目前，人们用不同的角度来描述镐与滚筒和岩石表面切割的相对位置通过他们和/或评估他们的个人和集体切割性能，包括攻角、间隙角度，前倾角，倾斜角，包角。攻击和倾斜角是在两个正交的平面来确定的拾取轴12的位置。尽管他们定义根据切割方向，它们不依赖于岩石表面。另一方面，间隙角和前倾角角是基于勒和岩石在切割平面上的表面。包角是用来确定鹤嘴在滚筒上的安排与不安排与岩石表面相联系的。另一个角度是倾斜角，这取决于包角，但它是岩石表面后减少倾向角度也与倾斜角有关。更多关于倾角在下一节给出。研究表明，攻角是一个主要的因子恳请力的选择15。两个倾斜角和倾角也将的作用力选择10,16,17。在用鼓切割岩石的过程中，截齿相对于岩石表面的位置起着重要的作用在镐和岩石上的作用力中起着重要作用突破的条件。作用在镐头和岩石上的力断接角产生的这个选择可以是检查镐头与岩石表面的相对位置，不仅仅是在它的切平面也在其法线平面上。虽然改变镐的攻角会改变它的相对角度位置到岩石表面的切割平面，变化镐的倾斜角度主要改变其相对位置正常的飞机。然而，倾斜角度不能单独确定这个相对位置，因为它是基于在鼓轴上，而不是岩石表面没有一个与滚筒轴的关系。来解决没有任何参数的问题的相对位置选择的岩石表面法向平面，一个新的参数命名为“斜角”本文提出并进行了讨论。一系列实验室进行了岩石切割实验研究在元代的倾斜角度和倾斜角度在磐石上岩石破裂方面的断裂(断裂)行为角度，沟槽形状，方向，以及力切割工具。没有类似实验的报道在现有的文献2. 倾斜角的概念，倾斜角，和倾斜的角度倾斜角，倾斜角和斜角，它们是本研究的焦点，都定义在法线平面上。2.1。倾斜角度。倾斜角度是关键参数之一确定在鼓上取镐的位置和手势。它已经被德和广泛应用于鼓设计。根据Sun和Li9的说法，镐头的倾斜角度是通常作为其截平面之间的夹角镐轴在其法线平面上的投影，如如图1所示。作为镐排设计的关键参数之一，倾斜角度对切削性能起着至关重要的作用镐头和鼓。研究表明，倾斜的角度对作用在刀盘上的力有明显的影响吗（鼓)16的实验研究报告最近17透露，掘进机上鹤嘴锄的倾斜角有一个最佳值，约为一半切角镐的破岩角。2.2。倾斜角。倾斜角度是相对于滚筒定义的，倾斜角度是基于被鼓切割的岩石表面。根据Hekimoglu和Ozdemir10，其倾斜角定义为采伐周长的斜角，为一个由镐的尖端组成的信封，在同一起点上相同的法线平面10(参考图2)显示了一个模拟岩石的突破模式为一个模拟滚筒的设计。根据Hekimoglu和Ozdemir10的说法，如果这些镐的倾斜角为零，那么周长就是一条倾斜的直线，如图所示（图2）。倾斜角实际上是切割的周长和滚筒的旋转轴上一个普通的飞机。显然，倾斜角可以随滚筒的转动而改变。在接下来的分析可知，斜面上的倾角为平行于滚筒前进方向(即脱壳)在12中定义的平面)被认为是由于岩石的突破图案定义在这个12平面上。此外，下式计算倾角给出Hekimoglu和Ozdemir在10中也是基于这个平面:其中I为倾角，为角距在两个相邻的选择之间，S是线这两个拣选之间的间隔，Vn是每转鼓的公转数，m是启动次数。e最大切割深度(DOC) Dmax由11给出式(1)可以改写为（3）由式(1)可知，随着滚筒推进距离的增加，滚筒倾角增大革命。需要注意的是，(1)仅用于一种特殊情况:镐间距均匀，不倾斜。挑片之间的角度差异是相等的，而且计算出的倾斜角有最大值。在其他情况下不适合计算倾角，例如，如果选择是倾斜的。然而，分析一般情况下不讨论倾角由于本文涉及的范围较广，本文将进一步讨论。对倾角的影响进行了一些探讨对表现的拣选虽然已经进行了在倾角的影响没有考虑;也就是说,现有的研究对倾角的影响是在倾斜角为零的情况下进行。2.3。倾斜角度。一个镐的斜角被定义为镐的轴与法线方向之间的角度岩石表面被镐切割(图3)。在开采过程中用滚筒切割岩石表面通常是弯曲的。在这种情况下，斜角是定义为镐的轴线与与切削周长垂直的线之间的夹角，用其测量法线平面(图4)。图4显示了另一个模拟岩石的破岩方式与模拟滚筒设计相同用于图2,但鼓不同推进距离每革命。如前一节所述，倾角随滚筒超前量的增加而增大每转一圈的距离，也可以用比较图2和图4。从图4可以看出，一个镐的倾斜角等于倾斜角为零时的倾斜角。在一般来说，镐头的倾斜角是当使用(4)时，应确保定义倾斜角、倾斜角和斜度的方向角是相等的。例如，如果一个积极的倾向角度是逆时针走的，既倾斜又倾斜也可以逆时针方向测量。如图4所示，当I为负，s为正，为零。显然,当是否为零，即被切割的岩石表面是否平行于滚筒的旋转轴，镐的倾斜角等于多少它的倾斜角度。然而，这在现实中非常罕见。的原因这是两个直线之间的角距离吗在真实的鼓中邻近的波通常不为零。根据(1)，I一般也是非零的(也指图2和图4)。因此，可以发现倾斜的角度一个镐的倾斜角一般不等于它在现实中的倾斜角根据(4). 结果在(图5)中进一步说明。上述发现对优化滚筒具有重要意义设计和操作因为在目前的实践中，力在线形岩石切割实验往往可以得到镐。在这类切削实验中，当镐的倾斜角设置为零时，镐的倾斜角也正常零。因此，使用力数据收集在这些实验对滚筒设计没有考虑倾斜角度的影响可能导致显著的偏置在镐和滚筒上的实际力的估计练习。原因是倾斜角有显着性对力量和突破模式的影响。3. 倾斜角的影响进行了一系列的岩石切割试验CSIRO岩石切割实验室调查岩石岩石破裂方面的断裂(断裂)行为角度，沟槽形状，方向，以及力切割工具。3.1。实验装置和方法。图6显示了测试中使用的实验装置。它基本上是一个刨床包括一个特殊的工具夹，一个镐，一个数据采集系统，和一个岩石块。系列专用刀具持有人是故意设计和制造生成倾斜角度和攻角的不同组合。在每次测试中，岩块都向镐的方向移动通过控制转速，并通过测力计的数据采集系统同时测量出作用在上面的三种力也就是，X方向的力，Y方向的力方向，Z方向的力。e测量部队在PC机上用LabVIEW系统进行记录。e X Y Z方向是基于坐标系定义的，如如图6所示:X轴是水平的，它是正的切削方向与切削方向相反前面的;Y轴是水平的，垂直于切割方向，其正方向指向左侧;Z轴垂直于XY平面，它是正的方向朝上。关于此的进一步资料刨床及其数据采集系统可以在16中找到。测试岩石是一种砂岩海利顿，澳大利亚，单轴压缩强度)37-40 MPa和BTS(巴西抗拉强度)4.6 - -4.8 MPa。在YZ平面内测量斜角e，从z轴开始。它的正方向是逆时针(图6)。在实验中，将岩石表面修剪为一个水平面;也就是说，它平行于XY平面。一个切割采用单镐线状切割测试。每次切割时，镐头的轨迹都是平行于轴。在这种情况下，岩石表面的倾斜角为零时，斜角就等于镐头的倾斜角。由于本文的主要目的是对斜面进行界定角度和检验的假设，倾斜角度可以显著影响岩石切割性能，只有试验考虑表1所示条件下的结果在报纸上。在表1中，只有倾斜角度是一个变量每个倾斜角度至少进行了三次切割。注意，在测试中，倾斜角度实际上被设置为7.5度和15度，而不是7.5度和15度。为了得到正斜角的力从试验结果上得到相应的结果负斜角，作如下假设: 如果只是一个斜角的方向是相反的，那么X和Z方向上的力保持不变力在Y轴上的绝对值(大小)方向也会一样。只有方向Y方向的力会反转是否因为岩体的假设是合理的被认为是同质的。3.2。测试结果和讨论。图7显示了一个示例用镐在不同的斜角上切出的凹槽切割16号槽的角度与切割16号槽的角度不同切割槽17、18和19)。在这个图中，沟槽17，十八个和十九个被镐切割成60度的攻角度，倾斜角度为15度，DOC为12mm。可以看出，沟槽是倾斜的;也就是说,在YZ平面内，任何沟槽截面积的平分线都不垂直于岩石表面。更重要的是，岩石切割实验揭示了尽管当镐是倾斜的时候凹槽是倾斜的，这是可能的槽截面积的平分线的旋转角度与倾斜角度不相等。假设这条直线的平分线的旋转角槽的横截面积等于可以倾斜角导致不可接受的错误。然而，影响对岩石破碎形状的倾斜角没有进一步的研究在这里。关于这类影响的研究将在一个单独的纸上。在下面的分析中，只有影响切割过程中产生的力的倾斜角度对过程进行了更详细的研究。切削试验表明，斜度对切削效果没有影响只有岩石突破的条件下，才有镐头的力量。一些平面位移和镐力的例子从测试中收集的数据如图8所示。在图8中, 蓝色连续线是记录的力，粉色线是记录的力折线是相应力的平均值。如表1所示，进行了岩石切割试验有五个不同的斜角，对于每个斜角，为了减少随机性，测试重复了三次测试数据中的错误。共进行了15次切割试验实现的。表2为测试结果平均值是用来识别的影响单个力的倾斜角。图9说明了平均值X, Y, Z方向上的平均力与斜角的关系。来使数字更清晰，原来的平均力数据不是标在这些数字里。表3总结了r平方值当应用不同的模型拟合图9中的数据时。图9显示所有的平均力都随着增加但它们都没有变化随着倾斜角的线性变化。从在图9和表3中，可以发现二次方程与线性模型相比，模型的拟合效果较好。在测试的倾斜角度范围内，两者的关系力与斜角之间可以模拟为如下: 其中，Fx, Fy, Fz是X, Y, Z上的平均力方向,分别。X方向。当倾斜角为0时，Y轴上的力方向是侧向力作用在镐上，而侧向力作用在镐上Z方向是对镐的法向力。然而,当镐在切割过程中是倾斜的，力在Y轴上方向不再代表横向力，而Z方向的力不再代表法线强制(参见图10)。一般情况下，切削力、侧向力和法向力作用可以从测得的X, Y和的力中计算出一个镐Z方向使用以下方程: Fc, Fl吗 Fn分别为切割、侧切和正常分别施加在镐上的力。图11描述了平均横向力和平均法向力随斜角的变化。从图9(a)可以看出切削力对镐的作用力随着镐的增加而显著增加斜角，因为切削力和X方向的力。图9(a)表明将倾斜角从0度增加到30度，切削力由5.9 kN增加到9.7 kN。从图11中，可以发现，两者的大小镐的侧向力和法向力也增加了随着倾斜角的增大有明显的变化。当倾斜角从0增加到30时，侧壁的厚度增大力从0 kN增加到5 kN，而法向力从5.6 kN增加到10 kN。ese结果表明斜角对所受力有显著影响凿岩机凿岩过程中的凿岩机值得注意的是，在镐力分析中，起作用的力在一个镐的切割过程中通常分为切削力、法向力和侧向力2,13。e切削力为与切削方向相反的力;正常的力是瞬时切削道与镐轴的切线所形成的垂直于切削方向和平面内的力;和横向力是垂直于物体形成的平面的力切割和法向力2。因此，切削力在挑上的力总是与在挑上的力相同4. 结论提出了一种新的角度“斜角”的确定方法十字镐与要凿入的岩石表面的相对位置镐的法平面。它是轴与轴之间的夹角截齿和岩石表面的法线方向;的斜角取决于倾斜角度和倾斜角。它随转鼓前进量的变化而变化。它是一个比倾斜角更好的变量来描述镐与岩石表面的相对位置;实验室岩石进行了切削试验，研究了斜度和倾斜度对切削力和岩石的影响断裂(断裂)的行为。以下主要发现从实验中得到: (i)槽体平分线的旋转角度横截面积可能与倾斜或倾斜的角度。假设这个旋转角度等于倾斜角会导致不可接受的误差。(ii)切割、横向和正常的大小锄头上的力都显著增加斜
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