Circular Cutters Research Articles

Numerical simulation study of PDC cutter rock breaking based on CT scanning to construct a rock model and apply a cohesive element to construct a discretization element

To more accurately simulate the interaction between a polycrystalline diamond compact (PDC) cutter and rock, the structural characteristics of basalt were analysed using computed tomography (CT), and a hard particle–matrix–pore three-phase rock model was established due to its structural characteristics. Three-dimensional models of the interaction between PDC cutters and rock were established by using the finite–discrete element method (FDEM). Using Voronoi diagrams to randomize the grid structure and optimize the propagation of cracks. This study revealed that a broken zone near the cutters will form during the rock breaking process, resulting in the affected area being larger than the area in contact with the formation rock. The rock breaking ability of circular cutters is stronger than that of conical cutters. When a conical cutter breaks hard particles, they are mainly striped or forced away from the rock, but circular cutters can divide hard particles into small pieces. The numerical model used in the research institute can effectively calculation results of the process of interaction between PDC cutter and rock, this proves that the application of the cohesive method to simulate rock breaking by PDC cutters is reliable.

Numerical simulation of the stress-strain state of snow and ice layer on the road when it is destroyed under the influence of the proposed device

In the winter season, we can observe the increased number of personal injuries and road vehicle accidents because of ice coating on paved roads. Surface refining from icing field involves two process operations: breaking it up and transporting the resulting segments. The basic process prevailing in cleaning effective output is the cutting process, i.e. the separation of icy fragments from the pavement with the cutting tools of special machines. The purpose of the research is to simulate the ice crust breaking influenced by the device designed by the authors. The modeling of ice flow failure is rather complicated and not a trivial task. An advanced Lagrangian model is applied in a modern software system. As a result, based on a computing model implemented in ANSYS software system, we have developed an algorithm for determining a mode of the ice crust deformation caused by the circular cutters put into it. The review of the stress strain behavior of ice crust shows that the biggest movement of ice crust fractions arises along the outline (perimeter) of discs and at the surface of the cover. The greatest equivalent stresses are observed along the disc outline (perimeter). The middle part of the disc (approaching to the centre) is nearly involved in equipment operation. The greatest displacement of icy particles is along the disc contour, while they are near zero along the edges. In the paper, we also determined recoverable and shearing deformations, regular and shear stresses in the ice crust at different thickness and movement speed of the device. The calculated motion rate and ice coating thickness at which the destructive effect is most distinctive, has been found out.

Influences of Boundary Temperature and Angular Velocity on Thermo-Elastic Characteristics of a Functionally Graded Circular Disk Subjected to Contact Forces

The behaviors of functionally graded (FG) engineering structures are influenced by various parameters, such as the boundary temperature, the angular velocity, variations in the thickness, the weight of the structure, and the loading state. The thermo-elastic characteristics of FG rotating circular disks under the loading of contact forces were investigated. Hooke’s law in plane stress problems was applied to derive a pair of partial differential equations and a finite volume method was developed due to the complexity of the governing equations. The thermo-elastic characteristics of the FG rotating disks were investigated according to the variations in their outer boundary temperature and angular velocity. The increase in the outer boundary temperature caused crack generation at the inner surface of the circular disk and on the opposite side to the loading point. The increase in the angular velocity caused unstable thermo-elastic behaviors near the area of the outer boundary surface, especially at 0.7<(r−a)/(b−a) < 0.9, and may have led to crack generation at the outer surface of the rotating disk. These results may be applied to the design of functionally graded circular cutters or grinding disks undergoing contact forces to produce proper and reliable thermo-elastic characteristics for practical applications.

Computerized generation and meshing simulation of face gear drives manufactured by circular cutters

The procedure of computerized generation and the results of simulation of meshing and stress analysis of face gear drives manufactured by circular cutters without considering the feed motion of the circular cutters is presented. A cutter profile tilt angle is introduced and investigated to approximate the generating surfaces of the circular cutter as much as possible to those of the theoretical reference shaper. Six different cases of design are considered to investigate the influence of design parameters on the contact patterns of the gear tooth surfaces. The results include the distribution of deviations of the face gear tooth surfaces with respect to the reference surface geometry generated by a shaper, the contact patterns, function of transmission errors, and the evaluation of stresses all over two cycles of meshing. The analysis of the results shows that the surface deviations due to the generation of the face gear by circular cutters can result in edge contacts, interference, and high stress concentration. However, if the appropriate design parameters for the circular cutters are properly evaluated as a result of simulation and applied as proposed here, the mechanical behavior of the face gear, by means of contact patterns and evolution of stresses can be as good as for the standard geometry of the face gears.

Computerized generation and gear mesh simulation of straight bevel gears manufactured by dual interlocking circular cutters

The computerized generation of straight bevel gears manufactured by dual interlocking circular cutters is developed, and the results of the simulation of meshing and contact as well as finite element analysis are shown. The geometry of the crown-rack that theoretically generates the reference octoidal gear is described and, based on it, the positioning of the generating interlocking circular cutters is determined. The influence of the radius of the cutting disks on the maximum bending stresses is investigated and the results exposed. The application of a blade angle to the cutting disks to provide straight bevel gears with longitudinal crowning has also been studied. The influence of the blade angle and disk radius on the amount of crowning applied to the gears is presented. It has been found that when no blade angle is applied and therefore line contact occurs, straight bevel gears generated by cuttings disks with a mean radius larger that a certain value yield lower bending stresses than similar octoidal gears without curved root geometry. For smaller radius, the maximum bending stresses increase exponentially. When the contact is localized by using a blade angle higher than zero, the effect of the curved root geometry of straight bevel gears generated by dual interlocking circular cutters is increased, yielding higher bending stresses with respect to equivalent theoretical octoidal gears with the same amount of longitudinal crowning but without curved root geometry.

Mechanical specific energy versus depth of cut in rock cutting and drilling

The relationship between Mechanical Specific Energy (MSE) and the Rate of Penetration (ROP), or equivalently the depth of cut per revolution, provides an important measure for strategizing a drilling operation. This study explores how MSE evolves with depth of cut, and presents a concerted effort that encompasses analytical, computational and experimental approaches. A simple model for the relationship between MSE and cutting depth is first derived with consideration of the wear progression of a circular cutter. This is an extension of Detournay and Defourny's phenomenological cutting model. Wear is modeled as a flat contact area at the bottom of a cutter referred to as a wear flat, and that wear flat in the past is often considered to be fixed during cutting. But during a drilling operation by a full bit that consists of multiple circular cutters, the wear flat length may increase because of various wear mechanisms involved. The wear progression of cutters generally results in reduced efficiency with either increased MSE or decreased ROP. Also, an accurate estimate of removed rock volume is found important for the evaluation of MSE. The derived model is compared with experiment results from a single circular cutter, for cutting soft rock under ambient pressure with actual depth measured through a micrometer, and for cutting high strength rock under high pressure with actual cutting area measured by a confocal microscope. Finally, the model is employed to interpret the evolution of MSE with depth of cut for a full drilling bit under confining pressure. The general form of equation of the developed model is found to describe well the experiment data and can be applied to interpret the drilling data for a full bit.

Comparison between Theoretical, Analytical & Experimental Vibration Analysis Method & Different Circular Tile Cutter by Using FFT&ANSYS

Circular cutters with uniform radial cracks are extensively used in the cutting processes. Unwanted noise, vibration & accidental failure associated with the cutting process have become an important economic and technological problem in the industry. The knowledge of natural frequencies of components is of great interest in the study of response of structures to various excitations. Hence, it is important to study a circular tile cutter with central hole, which fixed at inner edge and free at outer edge with its dynamic response. In this study some efforts are taken for analyzing vibration characteristics of tile cutter used in tile cutting industries with free boundary condition but having different (enlargement of stress concentration holes, slot end hole diameter ,numbers of cutting teeth’s, aspect ratio, effect of number and length of cracks, variable radial slit, circular concentric slit, thickness).Results From the FEA and FFT it is found that, this study is needful for design data preparation to avoid resonance and vibration in tile cutting industries from which finding out natural frequency and vibration w.r.t. different changes in tile cutter. Thus Theoretical, ANSYS & FFT results obtained are to be compared.

Research of New Machining Method of Skew Bevel Gears Based on Generation Line

According to generating principle of spiral bevel gear and space meshing theory, formation theory of generation line of tooth surface about skew bevel gears is studied. A new processing method of tooth surface with the generation line as chord of face circular cutters is put forward. Moving process model of milling processing with skew bevel gears is built, and profile of the gears can be machined using three axes linkage method based on the model. Machining test of the gears is carried out on experiment platform designed. Furthermore, 3D points cloud model of tooth surface are calculated in light of mathematical model of the tooth surface which has been established, and datum of mesh nodes on actual tooth surface are collected. Then surface errors is evaluated by normal vector equation of the tooth surface which has been developed. Finally, this method is proved to be effective and feasible.

Analysis and Manufacture of Skew Bevel Gears with Spherical Involute

Skew bevel gears are fundamental element of transmission system. Processing quality of skew bevel gears has impact on the performance of system. An accurate processing method of tooth surface of skew bevel gears with spherical involute is proposed. According to the space meshing theory, the meshing equation of skew bevel gears is built by the theory of coordinate transform. And the generating principle of generation line of tooth surface about skew bevel gears is studied. In terms of the formation theory of tooth surface, moving process model of milling processing is established. And the generation line is as chord of face circular cutters to cut the tooth surface. Machining of the profile of skew bevel gears is performed using three axes linkage by the method. Finally, the transmission experiment proves that this method can improve dynamics and strength characteristics.

Influence of rolling on the dynamic characteristics of circular saws and cutters

Influence of rolling on the dynamic characteristics of circular saws and cutters

GUTERL M-1

Abstract GUTERL M-1 is a highly-molybdenum, low-tungsten type of high-speed tool steel. It is a general-purpose high-speed steel with an excellent combination of cutting ability, finishing characteristics and toughness. Guterl M-1 has good cutting ability for all operations except for heavy-duty, continuous cutting applications that require the ultimate in red hardness. Its toughness is as great as that of other high-speed steels. Its typical uses include circular saws, broaches, gear cutters, twist drills and taps. This datasheet provides information on composition, physical properties, hardness, and elasticity. It also includes information on forming, heat treating, machining, joining, and surface treatment. Filing Code: TS-391. Producer or source: Guterl Special Steel Corporation.

Stability of stationary and rotating discs under edge load

The dominant dynamic instability mechanism in circular cutters, grinding wheels and the like is a moving load resonance excited by a constant transverse load at the “critical rotation speed.” The critical speed theory is extended here to include the effects of concentrated in-plane edge loads similar to loading occurring in engineering processes. The theoretical analysis shows the critical speed is only sensitive to edge load when the resonance mode and the mode of static edge load buckling are identical. This always occurs with large edge load, but it is not the case with the smaller edge loads typical of engineering processes. These analyses are confirmed through prediction and measurement of static buckling loads for centrally clamped discs with in-plane, concentrated loads inclined between 0° and 80° to the edge normal.

Analysis on determination of highest working parameters of circular cutters in mechanical processing of fish

Analysis on determination of highest working parameters of circular cutters in mechanical processing of fish

Geometry of circular cutter and its influence on specific cutting force of fish raw material

Presented, are the results of analysis relating to geometry of circular cutter and its influence on specific cutting force. Based on these analysis, are practical conclusions drawn for selection of circular cutters to be applied in mechanical cutting of fish.