The Numerical Simulations of Forces Acting on TBM Disc Cutters with the Consideration of Confining Pressure and Damage in Rocks

2011 ◽  
Vol 105-107 ◽  
pp. 1170-1174
Author(s):  
Hui Yun Li ◽  
Guang Yu Shi
Keyword(s):  
Penetration Depth ◽  
Cutting Forces ◽  
Confining Pressure ◽  
Material Model ◽  
Disc Cutter ◽  
Finite Element Software ◽  
Linear Dynamic ◽  
Dynamic Finite Element ◽  
Disc Cutters ◽  
The Relationship

This paper gives a brief explanation of the failure mechanism of rock fragmentation in rock cutting. The JOHNSON_HOLMGIST_CONCRETE is selected as the rock material model in numerical simulation with confining pressure and damage influence introduced. We use the non-linear dynamic finite element software LS/DYNA to simulate the dynamic process of cutting rock. The cutting forces acting on disc cutter are computed. The relationship between cutting forces and penetration depth, confining pressure and damage parameters are obtained. The results show that, the cutting forces increase with the penetration depth. They are larger in equal confining pressure than unequal condition. The forces are amplified with the damage parameters increasing. The conclusion provides a reference for the prediction of the cutting forces.

scholarly journals The Effects of Confining Stress on Rock Fragmentation by TBM Disc Cutters

2019 ◽  
Vol 2019 ◽  
pp. 1-13
Author(s):  
S. F. Zhai ◽  
S. H. Cao ◽  
M. Gao ◽  
Y. Feng
Keyword(s):  
Confining Pressure ◽  
Numerical Results ◽  
Rock Fragmentation ◽  
Disc Cutter ◽  
Confining Stress ◽  
Disc Cutters ◽  
Initiation And Propagation ◽  
Maximum Angle ◽  
Indentation Tests ◽  
Crushed Zone

In this paper, General Particle Dynamics (GPD3D) is developed to simulate rock fragmentation by TBM disc cutters under different confining stress. The processes of rock fragmentation without confining pressure by one disc cutter and two disc cutters are investigated using GPD3D. The crushed zone, initiation and propagation of cracks, and the chipping of rocks obtained from the proposed method are in good agreement with those obtained from the previous experimental and numerical results. The effects of different confining pressure on rock fragmentation are investigated using GPD3D. It is found that the crack initiation forces significantly increase as the confining stress increases, while the maximum angle of cracks decreases as the confining stress increases. The numerical results obtained from the proposed method agree well with those in previous indentation tests. Moreover, the effects of equivalent confining stress on rock fragmentation are studied using GPD3D, and it is found that rock fragmentation becomes easier when the equivalent confining stress is equal to 15MPa.

scholarly journals Dynamic Rock-Breaking Process of TBM Disc Cutters and Response Mechanism of Rock Mass Based on Discrete Element

2022 ◽  
Vol 2022 ◽  
pp. 1-10
Author(s):  
Qinglong Zhang ◽  
Yanwen Zhu ◽  
Canxun Du ◽  
Sanlin Du ◽  
Kun Shao ◽  
...  
Keyword(s):  
Rock Mass ◽  
Failure Modes ◽  
Confining Pressure ◽  
Rock Breaking ◽  
Disc Cutter ◽  
Repeated Loading ◽  
Response Mechanism ◽  
Disc Cutters ◽  
Crack Penetration ◽  
Cutter Spacing

Rock-breaking efficiency of full-face rock tunnel boring machine (TBM) is closely related to the performance of the disc cutter and the characteristics of the rock mass. In the point of view of mesomechanics, the particle flow code (PFC) is used to establish a numerical model of the rock mass and the disc cutter, and the process of TBM disc cutter intrusion into the rock mass is analyzed. The dynamic response mechanism and crack evolution process of the rock mass under the action of the disc cutter are studied on the basis of micromechanics, and the relationship between the rock mass crack, penetration, and cutting force during the intrusion of the disc cutter is revealed. The sensitivity analysis is carried out on the confining pressure conditions and the influence parameters of the disc cutter spacing. The results show that the rock breaking by disc cutter undergoes the transformation characteristics of compaction, shearing, and tension failure modes, and the failure process of the rock mass is the joint action of tension and shear. In the whole process of rock breaking, the disc cutter has the phenomenon of repeated loading-unloading alternation and leaping rock breaking; after the penetration of the disc cutter reached 9.0 mm, penetration creaks begin to appear on the surface of the rock mass; the penetration was obviously reduced with the increase of confining pressure, and it is mainly the penetration cracks on the surface; after the disc cutter spacing reaches 100.0 mm, there is no penetration crack between the two disc cutters. The research conclusion can provide a reference for the disc cutter optimization design.

Impact Performance Analysis and Optimization of X-Sandwich Panels

2012 ◽  
Vol 204-208 ◽  
pp. 1017-1023
Author(s):  
Lin Wang ◽  
Ai Quan Ye
Keyword(s):  
Sandwich Panel ◽  
Sandwich Plate ◽  
Steel Plates ◽  
Rigid Sphere ◽  
Impact Performance ◽  
Finite Element Software ◽  
Linear Dynamic ◽  
Dynamic Finite Element ◽  
Ordinary Steel ◽  
Better Than

In this paper, ANSYS/LS-DYNA which is a non-linear dynamic finite element software is applied to simulate the processes of two kinds of X-sandwich plate hit by a rigid sphere. Ultimate-ly the sandwich plate can be used to replace some components of the traditional steel protective dev-ices aimed at improving the overall crashworthiness performance of protective devices. This paper analyzes the influence of two plates on crashworthiness. And based on the comparison between the sandwich plates and the equivalent flat plate, the results from numerical simulation show that the X-sandwich panel can provide an excellent crashworthiness.Tight type of X-sandwich board is perfor-ms better than the discrete and ordinary steel plates, which can be applied to bridge protection device.

The Finite Element Simulation of Disc Cutter of Different Diameter Breaking Rock

2013 ◽  
Vol 791-793 ◽  
pp. 742-745 ◽  
Author(s):  
An Ning Zhang ◽  
Zhao Feng Zhu ◽  
Feng Zhu
Keyword(s):  
Numerical Simulation ◽  
Finite Element ◽  
Element Model ◽  
Rock Breaking ◽  
Disc Cutter ◽  
Finite Element Software ◽  
Disc Cutters ◽  
Element Simulation ◽  
Breaking Mechanism ◽  
Different Depths

In this paper, finite element software ANSYS is used to simulate a process of disc cutters of different diameter breaking rock, get the curves of the load of disc cutter of different diameter breaking rock and the curves of the stress exerting on the cutters when the disc cutters cutting different depth. According to the rock breaking mechanism of disc cutter, and established five kinds of disc cutter of different diameter broken rock finite element model, and the numerical simulation was carried out. The loads of disc cutters of different diameter breaking rock and the stress exerting on the cutters are different when the disc cutters cutting different depths. According to the result of the analysis, draw the curve graph of the load of disc cutter breaking rock and the stress exerting on the cutters when the disc cutters of different diameter cutting different depth. According to the curve diagram, the load of disc cutter of different diameter cutting a certain depth and the stress of exerting on the disc cutters can be gotten. The simulative result is instructive for improving the design of disc cutter parameters and improving the development efficiency.

Research on the Optimal Disc Cutter Spacing for Rock-Breaking Based on ANSYS

2014 ◽  
Vol 664 ◽  
pp. 143-147
Author(s):  
Yan Li ◽  
Ke Zhang ◽  
Jian Sun ◽  
Hong Sun ◽  
Zi Nan Wang
Keyword(s):  
Finite Element ◽  
Rock Breaking ◽  
Rock Fragmentation ◽  
Cutting Process ◽  
Disc Cutter ◽  
Rock Stress ◽  
Fragmentation Efficiency ◽  
Finite Element Software ◽  
Disc Cutters ◽  
Cutter Spacing

Objective: To study the influence of disc cutter spacing on rock fragmentation efficiency and optimize cutter layout and improve the efficiency of disc cutter. Method: ANSYS, a finite element software was used to simulate double disc cutter cutting process. Result: Find a good corresponding relationship between penetration and cutter spacing. At the process of sandstone, if disc cutter spacing as 54 ~ 55 mm, rock crushing as the largest and rock fragmentation efficiency is the highest; with the penetration of 10 mm. If disc cutter spacing as 66~68.5mm, rock crushing as the largest and rock fragmentation efficiency is the highest with the penetration of 15 mm. Changing the cutter spacing and penetration, rock stress and broken degree will also change. Conclusion: Double disc cutters change within the range of best cutter spacing, cutter spacing is proportional to the rock crushing. If the cutter distance is greater than the best cutter spacing, the ledge will be appeared. For one type of rocks, the penetration would have some effects on the optimal cutter spacing. If the penetration increases, the optimal cutter spacing increases gradually, at the time of other construction parameters unchanged.

Numerical Modeling of the Effects of Wears on Cutting Loads

2011 ◽  
Vol 308-310 ◽  
pp. 2340-2344 ◽  
Author(s):  
Xiao Yu Wang ◽  
Zong Xi Cai ◽  
Peng Cheng Su ◽  
Hai Feng Zhao ◽  
Yi Lan Kang
Keyword(s):  
Numerical Simulation ◽  
Numerical Modeling ◽  
Numerical Simulations ◽  
Penetration Depth ◽  
Normal Force ◽  
Disc Cutter ◽  
Fem Model ◽  
Simulation Results ◽  
Modified Formula ◽  
The Relationship

In order to determine the normal force acting on the TBM disc cutter, a 3-D FEM model is established to simulate the cutting process, with the failure effect of the rock. Afterwards, by using this model, a series of numerical simulations are performed. Based on the numerical simulation results, via modifying Evans formula, an improved formula is given. The modified formula indicates the relationship between the normal force acting on a single disc cutter and the penetration depth, and contains the influence of formation stress and wear.

scholarly journals Experimental Study and Simulation Calculation of the Chloride Resistance of Concrete under Multiple Factors

2021 ◽  
Vol 11 (12) ◽  
pp. 5322
Author(s):  
Yang Ding ◽  
Tong-Lin Yang ◽  
Hui Liu ◽  
Zhen Han ◽  
Shuang-Xi Zhou ◽  
...  
Keyword(s):  
Hydrostatic Pressure ◽  
Penetration Depth ◽  
Chloride Ion ◽  
Cementitious Materials ◽  
Chloride Ions ◽  
Finite Element Software ◽  
Chloride Resistance ◽  
Simulation Calculation ◽  
Marine Concrete ◽  
Resistance Performance

Cement is widely used in marine concrete, and its resistance to chloride ion corrosion has been widely considered. In this paper, based on a laboratory test, the influence of different hydrostatic pressures, coarse aggregate contents and w/c ratios on the chloride resistance performance is analyzed. Based on COMSOL finite element software, a two-dimensional cementitious materials model is established, and the simulation results are compared with the experimental results. The results show that the penetration depth of chloride ions in cement increases with the increase of the w/c ratio. Under the hydrostatic pressure of 0 MPa, when the w/c ratio is 0.35, the penetration depth of chloride ions is 7.4 mm, and the simulation result is 8.0 mm. When the w/c ratio is 0.45, the penetration depth of chloride ions is 9.3 mm, and the simulation result is 9.9 mm. When the w/c ratio is 0.55, the penetration depth of chloride ions is 12.9 mm, and the simulation result is 12.1 mm. Under different hydrostatic pressures, the penetration depth of chloride ions obviously changes, and with the increase in hydrostatic pressure, the penetration depth of chloride ions deepens. Under the w/c ratio of 0.35, when the hydrostatic pressure is 0.5 MPa, the penetration depth of chloride ions is 11.3 mm, and the simulation result is 12.1 mm. When the hydrostatic pressure is 1.0 MPa, the penetration depth of chloride ions is 16.2 mm, and the simulation result is 17.5 mm.

Stresses in Ultrasonically Assisted Turning

2006 ◽  
Vol 5-6 ◽  
pp. 351-358 ◽  
Author(s):  
N. Ahmed ◽  
A.V. Mitrofanov ◽  
Vladimir I. Babitsky ◽  
Vadim V. Silberschmidt
Keyword(s):  
Ultrasonic Vibration ◽  
Vibration Frequency ◽  
Cutting Forces ◽  
Plastic Material ◽  
Process Zone ◽  
Three Dimensional ◽  
Rate Sensitivity ◽  
High Strength ◽  
Material Model ◽  
Shear Stresses

Ultrasonically assisted turning (UAT) is a novel material-processing technology, where high frequency vibration (frequency f ≈ 20kHz, amplitude a ≈15μm) is superimposed on the movement of the cutting tool. Advantages of UAT have been demonstrated for a broad spectrum of applications. Compared to conventional turning (CT), this technique allows significant improvements in processing intractable materials, such as high-strength aerospace alloys, composites and ceramics. Superimposed ultrasonic vibration yields a noticeable decrease in cutting forces, as well as a superior surface finish. A vibro-impact interaction between the tool and workpiece in UAT in the process of continuous chip formation leads to a dynamically changing stress distribution in the process zone as compared to the quasistatic one in CT. The paper presents a three-dimensional, fully thermomechanically coupled computational model of UAT incorporating a non-linear elasto-plastic material model with strain-rate sensitivity and contact interaction with friction at the chip–tool interface. 3D stress distributions in the cutting region are analysed for a representative cycle of ultrasonic vibration. The dependence of various process parameters, such as shear stresses and cutting forces on vibration frequency and amplitude is also studied.

Influence of powder characteristics on the properties of green compacts of Bi-2212 powders

1997 ◽  
Vol 12 (1) ◽  
pp. 21-27 ◽  
Author(s):  
D.-W. Yuan ◽  
M. D. Aesoph ◽  
J. Kajuch
Keyword(s):  
High Temperature ◽  
Confining Pressure ◽  
Plastic Behavior ◽  
Particle Sizes ◽  
Green Density ◽  
High Temperature Superconducting ◽  
Powder Characteristics ◽  
The Relationship ◽  
Powder In Tube ◽  
Superconducting Applications

With the growing potential for use of Bi-2212 powders in high temperature superconducting applications, it is important to understand the processing characteristics of the material. To meet this need, the present work established the relationship between confining pressure and green density for powders of different particle sizes and morphologies. Mechanical properties, including elastic and plastic behavior, of the resulting green compacts were also measured as a function of relative density. Particle size and size distribution are shown to have a significant impact on the properties of interest. The implications of such findings are discussed with respect to the powder-in-tube process for making high temperature superconducting wire and tape.

scholarly journals Numerical simulation of blanking process

2018 ◽  
Vol 157 ◽  
pp. 02038
Author(s):  
Peter Pecháč ◽  
Milan Sága
Keyword(s):  
Numerical Simulation ◽  
Finite Element ◽  
Steel Sheet ◽  
Plastic Material ◽  
Material Model ◽  
Rolled Steel ◽  
Finite Element Software ◽  
History Of ◽  
Cold Rolled ◽  
Blanking Process

This paper presents numerical simulation of blanking process for cold-rolled steel sheet metal. The problem was modeled using axial symmetry in commercial finite element software ADINA. Data obtained by experimental measurement were used to create multi-linear plastic material model for simulation. History of blanking force vs. tool displacement was obtained.

Sign in / Sign up

Export Citation Format

Share Document