scholarly journals Numerical Research on Cutting Force and Fracture Morphology of Rock Plate with Two Sides Fixed and Two Sides Free

2020 ◽  
Vol 2020 ◽  
pp. 1-14 ◽  
Author(s):  
Zhenguo Lu ◽  
Qingliang Zeng ◽  
Zhaosheng Meng ◽  
Zhiwen Wang ◽  
Guanshun Gao
Keyword(s):  
Numerical Model ◽  
Cutting Force ◽  
Mining Industry ◽  
Interaction Model ◽  
Fracture Morphology ◽  
Skew Angle ◽  
Conical Pick ◽  
Rock Interaction ◽  
Zero Degree ◽  
Two Sides

Conical pick is a diffusely applied cutting tool in rock excavation in the coal-mining industry. In order to enhance the capability of conical pick, a new rock cutting method based on increased free surface is proposed. To research the peak cutting force and fracture morphology, ANSYS/LS-DYNA is used to establish the conical pick and rock interaction model. To obtain the fracture morphology of rock plate, eroding contact, erosion element failure, and damage constitutive are considered in the numerical model. Mechanical properties test and rock plate cutting experiment are carried out to guarantee and verify the correctness of the numerical model. The width and height of rock plate influencing peak cutting force and fracture morphology are studied, and the stable peak cutting force is defined. Lower width and height contribute to more fragments in smaller dimension produced during the rock plate cutting process. Besides, higher skew angle leads to more fragments. The peak cutting force decreases with the increasing width and height of rock plate while reaching stable peak cutting force, and it reduces and then remains stable with the increasing cutting position and symmetrical with skew angle of zero degree.

scholarly journals Research on Cutting Characteristics of Rock Plate with Two Sides Fixed and Two Sides Free

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Zhenguo Lu ◽  
Qingliang Zeng ◽  
Zhihai Liu ◽  
Guanshun Gao ◽  
Peisi Zhong
Keyword(s):  
Compressive Strength ◽  
Cutting Force ◽  
Uniaxial Compressive Strength ◽  
Fracture Morphology ◽  
Theoretical Research ◽  
Cutting Depth ◽  
Conical Pick ◽  
Rock Fragments ◽  
Saw Blade ◽  
Two Sides

Conical pick wear is an urgent problem in the roadway excavation caused by hard rock difficult to break. The traditional method of increasing cutting power to improve cutting performance of conical pick significantly increases pick wear. In the paper, a saw blade and conical pick combined cutting method is proposed based on increased free surface. To research the fracture morphology and cutting force of rock plate, theoretical, numerical, and experimental methods are used. By theoretical research, the bending mechanical model of rock plate bending is established. The cutting position and the junction between the free sides and fixed sides are preferentially broken. A numerical model combining the erosion and damage constitutive model is built, and the cutting process of rock plate was presented. According to rock plate experiment, the peak cutting force increases with the increasing uniaxial compressive strength, thickness of rock plate, and cutting depth of conical pick and decreases with the increasing width and height of rock plate. Exponential relationships exist between peak cutting force and thickness, width and height of rock plate, and cutting depth of conical pick. Linear relationship exists between peak cutting force and uniaxial compressive strength. The size of rock fragments increases with uniaxial compressive strength, width, and height of rock plate.

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 Effects of Water Intake Layout along the Wharf Shoreline on Ships

2019 ◽  
Vol 26 (4) ◽  
pp. 165-171
Author(s):  
Xian-wei Kong ◽  
Lei Ding ◽  
Hai-cheng Liu ◽  
Jing Qu ◽  
Xiao-song Li
Keyword(s):  
Numerical Model ◽  
Water Level ◽  
Physical Model ◽  
Water Intake ◽  
Hydrodynamic Forces ◽  
Lateral Flow ◽  
Real Situation ◽  
The Real ◽  
Level Difference ◽  
Two Sides

Abstract The construction of a water intake along the wharf shoreline can realise the intensive and comprehensive utilisation of the shoreline. However, since the water intake will increase the lateral flow at the wharf and also the hydrodynamic forces on ships, it will bring risks to ships mooring and leaving. The effects of the water intake on ships are studied using a physical model, numerical model and standard formulas. The results show that it leads to an increase of the hydrodynamic forces acting on the ship when the standard formulas are used to calculate the forces without considering the water level difference between the two sides of the ship. The results of the physical model are closer to the real situation. Measures that can effectively reduce the influence of the water intake on ships are proposed by increasing the distance between the wharf front and the front of the water intake as well as the depth of the water inlet windows.

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 Numerical Simulation on Cutting and Fracturing of Rock Plate with One Side Fixed and Three Sides Free

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Zhenguo Lu ◽  
Qingliang Zeng ◽  
Zhaosheng Meng ◽  
Zhiwen Wang ◽  
Guanshun Gao
Keyword(s):  
Numerical Simulation ◽  
Cutting Force ◽  
Cutting Tool ◽  
Hard Rock ◽  
Rock Fracture ◽  
Rock Fragment ◽  
Conical Pick ◽  
Cutting Angle ◽  
Saw Blade ◽  
Element Erosion

Conical pick is a rock cutting tool that is commonly used in roadway driving. Pick wear frequently happens in the course of breaking hard rock. The current paper shows a new method to solve the problem of pick wear. The rock is preslit with the saw blade and then broken by the conical pick. In order to study the cutting force and features of rock fragment, the numerical model is built between rock plate and conical pick. And element erosion is added in the code to obtain the fracture result. The rock plate cutting testbed is made to testify the correctness of numerical simulation. The width, height, and thickness of the rock plate, as well as cutting angle and cutting position, which influence cutting force and rock fracture are studied. According to the results, there exist exponential relationships between cutting force and width and thickness of rock plate. In addition, a linear relationship is found between the cutting force and the height of rock plate. Furthermore, both the cutting angle and cutting depth have an influence on cutting force. In particular, the factors of thickness and height or rock plate have the most obvious influence on cutting force. It is proven that what is beneficial to rock fracture is higher height and lower thickness of rock plate.

Study on the cutting performance in machining assembled hardened steel workpiece with torus cutter

2019 ◽  
Vol 234 (4) ◽  
pp. 701-709
Author(s):  
Tao Chen ◽  
Weijie Gao ◽  
Guangyue Wang ◽  
Xianli Liu
Keyword(s):  
Tool Wear ◽  
Cutting Force ◽  
Surface Quality ◽  
Wear Mechanism ◽  
Hardened Steel ◽  
Cutting Performance ◽  
Machining Process ◽  
Machined Surface ◽  
Machined Surface Quality ◽  
Two Sides

Torus cutters are increasingly used in machining high-hardness materials because of high processing efficiency. However, due to the large hardness variation in assembled hardened steel workpiece, the tool wear occurs easily in machining process. This severely affects the machined surface quality. Here, we conduct a research on the tool wear and the machined surface quality in milling assembled hardened steel mold with a torus cutter. The experimental results show the abrasive wear mechanism dominates the initial tool wear stage of the torus cutter. As the tool wear intensifies, the adhesive wear gradually occurs due to the effect of alternating stress and impact load. Thus, the mixing effect of the abrasive and adhesive wears further accelerates tool wear, resulting in occurrence of obvious crater wear band on the rake face and coating tearing area on the flank face. Finally, the cutter is damaged by the fatigue wear mechanism, reducing seriously the cutting performance. With increase of flank wear, moreover, there are increasingly obvious differences in both the surface morphology and the cutting force at the two sides of the joint seam of the assembled hardened steel parts, including larger height difference at the two sides of the joint seam and sudden change of cutting force, as a result, leading to decreasing cutting stability and deteriorating seriously machined surface quality.

scholarly journals Investigation on the effect of changing rotary speed and weight bit on PCD cutter wear

2019 ◽  
Vol 10 (3) ◽  
pp. 1063-1068
Author(s):  
A. M. Abdul-Rani ◽  
Khairiyah Ibrahim ◽  
A. H. Ab Adzis ◽  
B. T. Maulianda ◽  
M. N. Mat Asri
Keyword(s):  
Interaction Model ◽  
Wear Model ◽  
Element Analysis ◽  
Rock Interaction ◽  
Optimum Range ◽  
Model And Simulation ◽  
Cutter Wear ◽  
Weight On Bit ◽  
Hard Formation ◽  
Rotary Speed

Abstract The research is to determine the optimum range of rotary speed and weight-on-bit value for interbedded formation to reduce PCD cutter wear rate. To simulate an interbedded formation, a combination of limestone as the soft formation and granite as the hard formation is selected. The research is conducted based on analysis of cutter-rock interaction model, wear model and simulation of PCD cutter using finite element analysis in ABAQUS software. The results show that the optimum range of weight on bit and rotary speed for limestone is between 1000 N, 21.4 RPM, and 4000 N, 85.6 RPM, while for granite it is between 1000 N, 21.4 RPM and 3000 N, 64.2 RPM.

scholarly journals Discrete Element Simulation of Conical Pick’s Coal Cutting Process under Different Cutting Parameters

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Jinxia Liu ◽  
Chao Ma ◽  
Qingliang Zeng ◽  
Kuidong Gao
Keyword(s):  
Angular Velocity ◽  
Cutting Force ◽  
Cutting Parameters ◽  
Discrete Element ◽  
Cutting Process ◽  
Conical Pick ◽  
Force Fluctuation ◽  
Installation Angle ◽  
Coal Cutting ◽  
Coal Particles

To explore how the cutting parameters affect the conical pick’s cutting force in coal cutting process, some simulation tests were carried with EDEM based on analysis of coal cutting process of conical pick and micro mechanical characteristic of coal particles. In this paper, traction speed, drum angular velocity, and installation angle of conical pick were considered as the main coal cutting parameters. The discrete element simulations were conducted under 7 sets of various cutting parameters, which were determined in the range of empirical parameters. From the results of the simulation tests, it can be concluded that the fragmentation of coal particles appears in a compacted, squeezed, and crumbling state in coal cutting process; the traction speed has the greatest impact on the conical pick’s cutting force and cutting force fluctuation and the influence of drum angular velocity and installation angle reduce in turn; the force and force fluctuation tend to decrease and obviously increase, respectively, with the increase of drum angular velocity and traction speed; and they will reach the minimum when the pick’s installation angle is 45° under certain traction speed and drum angular velocity.

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