scholarly journals Experimental and Numerical Studies on Rock Cutting with Saw Blade and Conical Pick Combined Cutting Method

2019 ◽  
Vol 2019 ◽  
pp. 1-14 ◽  
Author(s):  
Zhenguo Lu ◽  
Qingliang Zeng ◽  
Zhiwen Wang ◽  
Xu Li ◽  
Kuidong Gao
Keyword(s):  
Cutting Force ◽  
Element Model ◽  
Rock Cutting ◽  
Mechanical Tests ◽  
Cutting Performance ◽  
Physical Parameters ◽  
Plate Height ◽  
Conical Pick ◽  
Cutting Method ◽  
Positive Correlation

In the rock cutting process, conical pick wear is often encountered. In order to restrain this condition, a saw blades and conical pick combined cutting method was put forward. Saw blades were employed to slit the rock for increasing the free surface, and then the conical pick was used to break the rock. To research the cutting performance of the new cutting method, the corresponding experimental device and a three-dimensional finite element model are established. In order to obtain crack propagation and fragment separation and to study the fracture process of the rock plate, a damage constative model and failure mechanism were combined in the numerical model. The mechanical tests were carried out to achieve the mechanical parameters of the rock. To investigate different parameters affecting rock plate cutting performance, experiments with different compressive strengths, physical parameters, and cutting depths were carried out. Moreover, the confining pressures affecting the cutting performance were adopted to simulate deep mining conditions. The experimental results demonstrated that the peak cutting force shows the exponential positive correlation with compressive strength, thickness of the rock plate, and cutting depth of the conical pick, and exhibits the exponential positive correlation with rock plate height and width. Besides, the numerical simulation results show that peak cutting force and confining pressure have a binomial relationship.

scholarly journals Numerical Simulation of Rock Plate Cutting with Three Sides Fixed and One Side Free

2018 ◽  
Vol 2018 ◽  
pp. 1-21 ◽  
Author(s):  
Zhenguo Lu ◽  
Lirong Wan ◽  
Qingliang Zeng ◽  
Xin Zhang ◽  
Kuidong Gao
Keyword(s):  
Numerical Simulation ◽  
Cutting Force ◽  
Cutting Speed ◽  
Rock Cutting ◽  
Numerical Results ◽  
Peak Force ◽  
Cutting Performance ◽  
Conical Pick ◽  
Cutting Method ◽  
Cutting Angle

In order to overcome conical pick wear in the traditional rock cutting method, a new cutting method was proposed on account of increasing free surface of the rock. The mechanical model of rock plate bending under concentrated force was established, and the first fracture position was given. The comparison between experimental and numerical results indicated that the numerical method is effective. A computer code LS-DYNA (3D) was employed to study the cutting performance of a conical pick. To study the rock size influenced on the cutting performance, the numerical simulations with different thickness, width, and height of a rock plate was carried out. The numerical simulation with the different cutting parameters of cutting speed, cutting angle, and cutting position influenced on cutting performance was also carried out. The numerical results indicated that the peak force increased with the increasing thickness of rock plate. With the increasing width and height of the rock plate, the peak force decreased and then became stable. Besides, the peak force decreased with the increasing of cutting position lxp/lx. Moreover, the peak force increased and then decreased with the increasing of cutting angle. The cutting speed has nonsignificant influence on the peak force. The strong exponential relationship was obtained between the peak force and cutting position, thickness, height, and width of the rock plate at a confidence level of 0.95. A binomial relationship was observed between the peak force and cutting angel. The cutting force comparison between traditional rock cutting and rock plate cutting indicated that the new cutting method can effectively reduce peak cutting force.

scholarly journals Numerical Simulation of Conical Pick Cutting Arc Rock Plate Fracture Based on ANSYS/LS-DYNA

2020 ◽  
Vol 2020 ◽  
pp. 1-16 ◽  
Author(s):  
Zhiwen Wang ◽  
Qingliang Zeng ◽  
Zhenguo Lu ◽  
Lirong Wan ◽  
Xin Zhang ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Cutting Force ◽  
Structural Parameters ◽  
Cutting Parameters ◽  
Rock Breaking ◽  
Central Axis ◽  
Plate Height ◽  
Conical Pick ◽  
Cutting Angle ◽  
Cutting Point

The new method of rock breaking based on the combination of circular sawblade and conical pick was proposed to improve the effectiveness of hard rock breaking. The numerical simulation method was applied to research the conical pick cutting arc rock plate by ANSYS/LS-DYNA. The conical pick cutting arc rock plate numerical simulation model was established to research the influence of arc rock plate structural parameters and cutting parameters on cracks formation and propagation of the arc rock plate and the cutting force in the process of conical pick cutting arc rock plate. The amount of cracks is positively correlated with arc rock plate thickness, the cutting speed, and distance of cutting point to arc rock plate central axis and negatively correlated with the cutting angle. The mean peak cutting force is positively correlated with the thickness of arc rock plate and the distance of cutting point to arc rock plate central axis; however, it is negatively correlated with the arc rock plate height and width and cutting angle of conical pick. The simulation results can be used to predict the conical pick work performance with various cutting parameters and structural parameters.

scholarly journals Investigation of the influence mechanism of rock damage on rock fragmentation and cutting performance by the discrete element method

2019 ◽  
Vol 6 (5) ◽  
pp. 190116 ◽  
Author(s):  
Si-fei Liu ◽  
Shuai-feng Lu ◽  
Zhi-jun Wan ◽  
Jing-yi Cheng
Keyword(s):  
Cutting Force ◽  
Rock Cutting ◽  
Rock Breaking ◽  
Pulse Number ◽  
Rock Fragmentation ◽  
Cutting Performance ◽  
Tensile Failure ◽  
Rock Damage ◽  
Damage Factor ◽  
Mining Machinery

Rock damage is one of the key factors in the design and model choice of mining machinery. In this paper, the influence of rock damage on rock fragmentation and cutting performance was studied using PFC 2D . In PFC 2D software, it is feasible to get rock models with different damage factors by reducing the effective modulus, tensile and shear strength of bond by using the proportional factors. A linear relationship was obtained between the proportion factor and damage factor. Furthermore, numerical simulations of rock cutting with different damage factors were carried out. The results show that with the increase of damage factor, the rock cutting failure mode changes from tensile failure to brittle failure, accompanied by the propagation of macro cracks, the formation of large debris and a notable decrease in the peak cutting force. The mean cutting force is negatively correlated with the damage factor. Besides this, the instability of cutting force was evaluated by the fluctuation index and the pulse number of unit displacement. It was found that the cutting force was quite stable when the damage factor was 0.3, which improves the reliability of cutting machines. Finally, the cutting energy consumption of rock cutting with different damage factors was analysed. The results reveal that an increase of damage factor can raise the rock cutting efficiency. The aforementioned findings play a significant role in the development of assisted rock-breaking technologies and the design of cutting head layout of mining machinery.

3D Finite Element Simulation for Turning of Hardened 45 Steel

2019 ◽  
Vol 13 (2) ◽  
pp. 181-188
Author(s):  
Meng Liu ◽  
Guohe Li ◽  
Xueli Zhao ◽  
Xiaole Qi ◽  
Shanshan Zhao
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Cutting Force ◽  
Finite Element Simulation ◽  
Orthogonal Experiment ◽  
Element Model ◽  
3D Finite Element ◽  
Element Simulation ◽  
Metal Machining ◽  
Single Factor Experiment

Background: Finite element simulation has become an important method for the mechanism research of metal machining in recent years. Objective: To study the cutting mechanism of hardened 45 steel (45HRC), and improve the processing efficiency and quality. Methods: A 3D oblique finite element model of traditional turning of hardened 45 steel based on ABAQUS was established in this paper. The feasibility of the finite element model was verified by experiment, and the influence of cutting parameters on cutting force was predicted by single factor experiment and orthogonal experiment based on simulation. Finally, the empirical formula of cutting force was fitted by MATLAB. Besides, a lot of patents on 3D finite element simulation for metal machining were studied. Results: The results show that the 3D oblique finite element model can predict three direction cutting force, the 3D chip shape, and other variables of metal machining and the prediction errors of three direction cutting force are 5%, 9.02%, and 8.56%. The results of single factor experiment and orthogonal experiment are in good agreement with similar research, which shows that the model can meet the needs for engineering application. Besides, the empirical formula and the prediction results of cutting force are helpful for the parameters optimization and tool design. Conclusion: A 3D oblique finite element model of traditional turning of hardened 45 steel is established, based on ABAQUS, and the validation is carried out by comparing with experiment.

scholarly journals The Comparative Study on Cutting Performance of Different-Structure Milling Cutters in Machining CFRP

2018 ◽  
Vol 8 (8) ◽  
pp. 1353
Author(s):  
Tao Chen ◽  
Fei Gao ◽  
Suyan Li ◽  
Xianli Liu
Keyword(s):  
Carbon Fiber ◽  
Cutting Force ◽  
Surface Quality ◽  
Cutting Edge ◽  
Cutting Performance ◽  
Machining Process ◽  
Carbon Fiber Composites ◽  
Machined Surface ◽  
Milling Cutter ◽  
Machined Surface Quality

Carbon fiber reinforced plastic (CFRP) is typically hard to process, because it is easy for it to generate processing damage such as burrs, tears, delamination, and so on in the machining process. Consequently, this restricts its wide spread application. This paper conducted a comparative experiment on the cutting performance of the two different-structure milling cutters, with a helical staggered edge and a rhombic edge, in milling carbon fiber composites; analyzed the wear morphologies of the two cutting tools; and thus acquired the effect of the tool structure on the machined surface quality and cutting force. The results indicated that in the whole cutting, the rhombic milling cutter with a segmented cutting edge showed better wear resistance and a more stable machined surface quality. It was not until a large area of coating shedding occurred, along with chip clogging, that the surface quality decreased significantly. At the stage of coating wear, the helical staggered milling cutter with an alternately arranged continuous cutting edge showed better machined surface quality, but when the coating fell off, its machined surface quality began to reveal damage such as groove, tear, and fiber pullout. Meanwhile, burrs occurred at the edge and the cutting force obviously increased. By contrast, for the rhombic milling cutter, both the surface roughness and cutting force increased relatively slowly.

scholarly journals Preparation and cutting performance of nano-scaled Al2O3-coated micro-textured cutting tool prepared by atomic layer deposition

2021 ◽  
Vol 40 (1) ◽  
pp. 77-86
Author(s):  
Siwen Tang ◽  
Pengfei Liu ◽  
Zhen Su ◽  
Yu Lei ◽  
Qian Liu ◽  
...  
Keyword(s):  
Friction Coefficient ◽  
Atomic Layer Deposition ◽  
Cutting Force ◽  
Cutting Tool ◽  
Orthogonal Cutting ◽  
Cutting Tools ◽  
Atomic Layer ◽  
Cutting Performance ◽  
Cutting Test ◽  
Layer Deposition

Abstract Al2O3 nano-scaled coating was prepared on micro-textured YT5 cemented carbide cutting tools by atomic layer deposition ALD. The effect of Al2O3 nano-scaled coating, with and without combined action of texture, on the cutting performance was studied by orthogonal cutting test. The results were compared with micro-textured cutting tool and YT5 cutting tool. They show that the micro-texture and nano-scaled Al2O3 coated on the micro-texture both can reduce the cutting force and friction coefficient of the tool, and the tools with nano-scaled Al2O3 coated on the micro-texture are more efficient. Furthermore, the friction coefficient of the 100 nm Al2O3-coated micro-texture tool is relatively low. When the distance of the micro-pits is 0.15 mm, the friction coefficient is lowest among the four kinds of pit textured nanometer coating tools. The friction coefficient is the lowest when the direction of the groove in strip textured nanometer coating tool is perpendicular to the main cutting edge. The main mechanism of the nanometer Al2O3 on the micro-textured tool to reduction in cutting force and the friction coefficient is discussed. These results show that the developed tools effectively decrease the cutting force and friction coefficient of tool–chip interface.

Updating Finite Element Model of Combined Structures on the Basis of Dynamic Test Results

1996 ◽  
Author(s):  
Chen Xin ◽  
Qin Ye ◽  
Yuan Xiguang ◽  
Zhang Ping ◽  
Sun Jian
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Test Data ◽  
Dynamic Test ◽  
Element Model ◽  
Physical Parameters ◽  
Structural Joint ◽  
Combined Structure ◽  
Joint Parameters ◽  
Two Stages

Abstract According to the real situation, a new method of updating the finite element model (FEM) of a combined structure step by step is proposed in this paper. It is assumed that there are two types of error when establishing the FEMs. One of them results from the simplifications, in fact, it is severe for complicated structures, which usually assume many simplifications; the other is from the process of identifying structural joint parameters. For this reason, it is recommended that the FEM should be established in two stages. At the first stage, the local physical parameters relating with the simplifications are corrected by using the dynamic test data of the corresponding substructures. Then, the structural joint parameters that link the substructures are corrected by the dynamic test data of the combined structure as a whole. The updating formula is presented and proved, and its algorithm is also described. And the experimental results show that the efficiency and accuracy of the proposed method are quite satisfactory.

scholarly journals Influence of Ultrasonic Vibration-Assisted Ball-End Milling on the Cutting Performance of AZ31B Magnesium Alloy

2020 ◽  
Vol 9 (4) ◽  
pp. 271-276
Keyword(s):  
Surface Roughness ◽  
Cutting Force ◽  
Ultrasonic Vibration ◽  
Biomedical Applications ◽  
End Milling ◽  
Cutting Temperature ◽  
Cutting Performance ◽  
Machining Process ◽  
Dry Conditions ◽  
Good Biocompatibility

Magnesium alloys have a tremendous possibility for biomedical applications due to their good biocompatibility, integrity and degradability, but their low ignition temperature and easy corrosive property restrict the machining process for potential biomedical applications. In this research, ultrasonic vibration-assisted ball milling (UVABM) for AZ31B is investigated to improve the cutting performance and get specific surface morphology in dry conditions. Cutting force and cutting temperatures are measured during UVABM. Surface roughness is measured with a white light interferometer after UVABM. The experimental results show cutting force and cutting temperature reduce due to ultrasonic vibration, and surface roughness decreases by 34.92%, compared with that got from traditional milling, which indicates UVABM is suitable to process AZ31B for potential biomedical applications.

Cutting Force Empirical Model of High-Speed Precision Hard Cutting GCr15

2009 ◽  
Vol 69-70 ◽  
pp. 301-305
Author(s):  
Jing Shu Hu ◽  
Yuan Sheng Zhai ◽  
Fu Gang Yan ◽  
Yu Fu Li ◽  
Xian Li Liu
Keyword(s):  
Cutting Force ◽  
Empirical Model ◽  
High Speed ◽  
Orthogonal Design ◽  
Cutting Speed ◽  
Least Square Method ◽  
Cutting Parameters ◽  
Least Square ◽  
Physical Parameters ◽  
Hard Cutting

In the cutting process, cutting force is one of the important physical parameters, which affects the generation of cutting heat, tool life and surface precision of workpiece directly. In this paper an orthogonal design of experiment and subsequent data is analyzed using high speed finish hard cutting GCr15 whose hardness is 65HRC. Cutting speed is 200-400m/min, to study the influence of cutting parameters on cutting force, cutting force empirical model has obtained from least square method.

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