Modelling Changes in the Dynamic Response of a Cantilever Beam During the Machining Process Using the Discrete Element Method

2016 ◽  
Author(s):  
Anders H. Andersen ◽  
Frederik F. Foldager ◽  
Kasper Ringgaard ◽  
Ole Balling
Keyword(s):  
Finite Element ◽  
Discrete Element Method ◽  
Cantilever Beam ◽  
Element Model ◽  
Discrete Element ◽  
Machining Process ◽  
Discrete Element Model ◽  
Machining Processes ◽  
Element Analysis ◽  
Element Method

Production of high accuracy components often involves machining processes. If the machining processes are pushed to increase productivity, it can become challenging to comply with strict tolerances and surface finish requirements. Both the finite element method and the discrete element method have been used for off-line deflection compensation and stability analysis. This contribution investigates the capabilities of a simplified discrete element model in the use for offline simulation of the dynamic behavior of a workpiece during machining. A cantilever beam is modelled and the natural frequencies are monitored as material is removed. Results are compared with theoretical frequencies and with finite element analysis. The model shows a good correspondence in the frequency behavior as material is removed compared with finite element results, though the simple discrete element model under-predicts the stiffness of the beam with approximate 5% for the first two modes.

Study on Machining Mechanism of Glass Using Discrete Element Method

2014 ◽  
Vol 577 ◽  
pp. 108-111 ◽  
Author(s):  
Ying Qiu ◽  
Mei Lin Gu ◽  
Feng Guang Zhang ◽  
Zhi Wei
Keyword(s):  
Discrete Element Method ◽  
Element Model ◽  
Discrete Element ◽  
Rake Angle ◽  
Milling Process ◽  
Micro Milling ◽  
Discrete Element Model ◽  
Machined Surface ◽  
Damage Depth ◽  
Element Method

The discrete element method (DEM) is applied to glass micromachining in this study. By three standard tests the discrete element model is established to match the main mechanical properties of glass. Then, indentating, cutting, micro milling process are simulated. Results show that the vertical damage depth is prevented from reaching the final machined surface in cutting process. Tool rake angle is the most remarkable factor influencing on the chip deformation and cutting force. The final machined surface is determined by the minimum cutting thickness per edge. Different cutting thickness, cutter shape and spindle speed largely effect on the mechanism of glass.

Discrete Element Method Simulation of Residual Stresses in Grinding of Granite with Single Diamond Grain

2013 ◽  
Vol 300-301 ◽  
pp. 1304-1308
Author(s):  
Liang Kang ◽  
Yong Ye
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Discrete Element Method ◽  
Element Model ◽  
Discrete Element ◽  
Discrete Element Model ◽  
Cutting Depth ◽  
Discrete Element Method Simulation ◽  
Diamond Grain ◽  
Element Method

The discrete element model and the model of single diamond grain grinding process of granite were constructed through numerical simulation and calibration of mechanical properties. Based on the models, the grinding processes of granite was dynamically simulated, and the effects of different rank angles, grinding speeds and cutting depths on the distribution of residual stresses as the depth of workpiece were also analyzed. The results show that the residual stress in the workpiece is relatively small after grinding when the tool rank angle lays in a small negative (-200 to 00). Otherwise, when the tool rank angle is too large or too small, there is a significant residual stress. The residual stresses in the workpiece increase with the increase of grinding speed and cutting depth. The residual stress nephogram was accomplished and the generated mechanism of residual stress was also analyzed. The results proved that the discrete element method (DEM) is an effective way to analyze the residual stress

Application of the Discrete Element Method (DEM) to Evaluate Pipeline Response to Slope Movement

2016 ◽  
Author(s):  
Abdelfettah Fredj ◽  
Aaron Dinovitzer ◽  
Amir Hassannejadasl ◽  
Richard Gailing ◽  
Millan Sen
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Discrete Element Method ◽  
Land Surface ◽  
Numerical Models ◽  
Discrete Element ◽  
Slope Movement ◽  
Ground Movement ◽  
Element Analysis ◽  
Element Method

The long linear nature of buried pipelines results in the risk of interaction with a range of geotechnical hazards including active slopes and land surface subsidence areas. Ground movement induced by these geotechnical hazards can subject a pipeline to axial, lateral flexural, and vertical flexural loading. The techniques to predict pipeline displacements, loads, stresses or strains are not well described in design standards or codes of practice. The results of geotechnical site observation, successive in-line inspection or pipeline instrumentation are used to infer pipeline displacement or strain accumulation and these techniques are often augmented through the application of finite element analysis. The practice of using finite element analysis for pipe-soil interaction has developed in recent years and is proving to be a useful tool in evaluating the pipeline behavior in response to ground movement. This paper considers pipeline response to geotechnical hazard-induced loading scenarios related to slope movement transverse to the pipeline axis. The details of the three-dimensional LS-DYNA-based BMT pipe-soil interaction model employing a discrete element method (DEM) are presented in this paper. The validation of the numerical models through comparison with medium-scale physical pipe-soil interaction tests are described to demonstrate that the models are capable of accurately simulating real world events. The models are further calibrated for nominal soil types to replicate the pipe-soil load displacement properties outlined in ASCE guideline recommendations by developing responses that closely agree with these results from the physical trials and engineering judgement. The utility of advanced pipe-soil interaction modelling in supporting strain-based pipeline integrity management or design is demonstrated by presenting the results of geotechnical hazard numerical simulations. These simulations are used to describe the sensitivity of pipeline displacements and strains to the demands of these geotechnical events and develop relationships between the geotechnical event key parameters and pipeline response.

Numerical analysis on tractive performance of off-road tire on gravel road using a calibrated finite element method–discrete element method model and experimental validation

2020 ◽  
Vol 234 (14) ◽  
pp. 3440-3457
Author(s):  
Weipan Xu ◽  
Haiyang Zeng ◽  
Peng Yang ◽  
Mengyan Zang
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Discrete Element Method ◽  
Triaxial Compression ◽  
Element Model ◽  
Discrete Element ◽  
Wheel Load ◽  
Method Model ◽  
Gravel Road ◽  
Element Method

The interaction between off-road tires and granular terrain has a great influence on the tractive performance of off-road vehicles. However, the finite element method or the discrete element method cannot effectively study the interaction between off-road tires and granular terrain. The three-dimensional combined finite element and discrete element method is applied to handle this problem. In this study, a calibrated finite element method–discrete element method model is established, in which the finite element model of off-road tire is validated by stiffness tests, while the discrete element model of gravel particles is validated by triaxial compression tests. The calibrated finite element method–discrete element method model can describe the structural mechanics of the off-road tire and the macroscopic mechanical properties of the gravel road. Tractive performance simulations of the off-road tire on gravel road under different slip conditions are performed with the commercial software LS-DYNA. The simulation results are basically corresponded with the soil-bin test results in terms of granular terrain deformation and tractive performance parameters versus the slip rates. Finally, the effects of tread pattern, wheel load, and tire inflation pressure on tractive performance of off-road tire on granular terrain are investigated. It indicates that the calibrated finite element method–discrete element method can be an effective tool for studying the tire–granular terrain interaction and predicting the tractive performance of off-road tire on granular terrain.

The Application of Discrete Element Method in the Analysis of Stone Arch Bridge

2013 ◽  
Vol 361-363 ◽  
pp. 1255-1258
Author(s):  
Yuan Xu Yu ◽  
Yue Zhang
Keyword(s):  
Discrete Element Method ◽  
Damage Identification ◽  
Element Model ◽  
Discrete Element ◽  
Load Test ◽  
Main Bearing ◽  
Element Analysis ◽  
Arch Bridge ◽  
Bridge Model ◽  
Element Method

Demonstrate the feasibility of the discrete element method application in the stone arch bridge analysis. Put forward simulation and analysis methods of stone arch bridge with fracture and damage. Using UDEC two-dimensional discrete element analysis software to establish arch bridge model, establish a load test state and simulate the overload test, make a force and damage identification via analyzing the main bearing structure arch ring. Discrete element model calculation result has good consistency with the actually measured value. Using the discrete element method can be effectively considered discrete problems of masonry materials, and accurate simulate the discrete characteristics of arch bridge structure materials.

Modeling of Shield Machine Tunneling Experiment by Discrete Element Method

2014 ◽  
Vol 556-562 ◽  
pp. 1200-1204 ◽  
Author(s):  
Li Wu ◽  
Chang Liu
Keyword(s):  
Discrete Element Method ◽  
Model Experiment ◽  
Element Model ◽  
Discrete Element ◽  
Discrete Element Model ◽  
Rotation Direction ◽  
Particle Parameters ◽  
Shield Machine ◽  
Element Method

To discover the interaction rules between the cutterhead of shield machine and the soils, the model experiment of shield machine tunneling is performed, and the particle discrete element model of the experiment is built. By adjusting the particle parameters, the simulated cutterhead torque is compatible with the experiment observed results. Then the displacement of soils in the front of the cutterhead, behind the cutterhead, and in the front of the chamber board is obtained. The soils in the front of the cutterhead try to flow into the nearest opening. However, the soils behind the cutterhead move toward the wall of out barrel. The movement of soils in front of the chamber board is in accordance with the rotation direction of the cutterhead.

scholarly journals Numerical simulation on coal loading process of shearer drum based on discrete element method

2021 ◽  
pp. 014459872110135
Author(s):  
Zhen Tian ◽  
Shuangxi Jing ◽  
Lijuan Zhao ◽  
Wei Liu ◽  
Shan Gao
Keyword(s):  
Numerical Simulation ◽  
Discrete Element Method ◽  
Loading Rate ◽  
Low Cost ◽  
Element Model ◽  
Discrete Element ◽  
Helix Angle ◽  
Loading Process ◽  
Coal Particles ◽  
Element Method

The drum is the working mechanism of the coal shearer, and the coal loading performance of the drum is very important for the efficient and safe production of coal mine. In order to study the coal loading performance of the shearer drum, a discrete element model of coupling the drum and coal wall was established by combining the results of the coal property determination and the discrete element method. The movement of coal particles and the mass distribution in different areas were obtained, and the coal particle velocity and coal loading rate were analyzed under the conditions of different helix angles, rotation speeds, traction speeds and cutting depths. The results show that with the increase of helix angle, the coal loading first increases and then decreases; with the increase of cutting depth and traction speed, the coal loading rate decreases; the increase of rotation speed can improve the coal loading performance of drum to a certain extent. The research results show that the discrete element numerical simulation can accurately reflect the coal loading process of the shearer drum, which provides a more convenient, fast and low-cost method for the structural design of shearer drum and the improvement of coal loading performance.

scholarly journals Analysis of Forces in Vibro-Impact and Hot Vibro-Impact Turning of Advanced Alloys

2011 ◽  
Vol 70 ◽  
pp. 315-320 ◽  
Author(s):  
Riaz Muhammad ◽  
Agostino Maurotto ◽  
Anish Roy ◽  
Vadim V. Silberschmidt
Keyword(s):  
Finite Element ◽  
Cutting Forces ◽  
Three Dimensional ◽  
Element Model ◽  
Machining Process ◽  
Strain Rates ◽  
Machining Processes ◽  
Machined Surface ◽  
Cutting Zone

Analysis of the cutting process in machining of advanced alloys, which are typically difficult-to-machine materials, is a challenge that needs to be addressed. In a machining operation, cutting forces causes severe deformations in the proximity of the cutting edge, producing high stresses, strain, strain-rates and temperatures in the workpiece that ultimately affect the quality of the machined surface. In the present work, cutting forces generated in a vibro-impact and hot vibro-impact machining process of Ti-based alloy, using an in-house Ultrasonically Assisted Turning (UAT) setup, are studied. A three-dimensional, thermo-mechanically coupled, finite element model was developed to study the thermal and mechanical processes in the cutting zone for the various machining processes. Several advantages of ultrasonically assisted turning and hot ultrasonically assisted turning are demonstrated when compared to conventional turning.

scholarly journals COMPARISON OF SAW BLADE NATURAL FREQUENCIES AND CRITICAL SPEEDS USING CSAW AND FINITE ELEMENT ANALYSIS

2011 ◽  
Author(s):  
J. Poirier ◽  
P. Radziszewski
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Natural Frequencies ◽  
Element Model ◽  
The Finite Element Method ◽  
Element Analysis ◽  
Saw Blade ◽  
Circular Saws ◽  
The Finite Element Model ◽  
Element Method

The natural frequencies of circular saws limit the operating speeds of the saws. Current industry methods of increasing natural frequency include pretensioning, where plastic deformation is induced into the saw. To better model the saw, the finite element model is compared to current software for steel saws; C-SAW, a software program that calculates frequencies for stiffened circular saws. Using C-SAW and the finite element method the results are compared and the finite element method is validated for steel saws.

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