Tutorial 2: Rock Cuting Disc 3D. Rock Cutting Disc

Transcription

1 Rock Cutting Disc This tutorial details the simulation of a process with granular non-cohesive material, concretely a Mill. Advanced and specific aspects should be clarified during training seminars using the present document as reference. Important aspects: - Wizard Interface - Element Types - Mesh Properties - Kinematic Conditions - Contacts - Mesh Generation - Output - Running the Simulation - Results

2 Previous GiD commands: Basic GiD colours criterion:. New GiD project Points: Black. Open GiD project Lines: Blue 3. Save GiD project Surfaces: Purple 4. GiD preferences Volumes: Cyan 5. Zoom in Nodes: Black 6. Zoom out Elements: Green 7. Zoom frame 8. Redraw 9. Rotate trackball 0. Pan dynamic Attention: To accept the conditions assigned the user has to push the Esc button of the keyboard General Preferences Graphical Preferences Meshing Preferences

3 Access to the wizard menu:. Open GiD 0. Select the ProblemType DEMPack v.0 3. Select the case to simulate. 4. Select the dimension. 5. Begin the problem simulation.. Rock Cutting Disc an Pick are only available in 3D. Once inside the wizard interface, there is a menu access available 3

4 Geometry: Basic Available Tools Normals Control Basic tools to create the geometry,. Points Lines3 Surfaces4 Disc detail. To create more complex geometries use the GiD geometry toolbar. The geometry can be imported from CAD formats accepted by GiD (IGES, DXF ) 3. To create the lines, two points are needed 4. To create the surfaces, a closed line contour is needed 5. The geometric model can be imported using CAD formats accepted by GiD 4

5 Geometry: Basic Available Tools Normals Control Pick all the surfaces with bad normal orientation in order to change its sense. Bad Disc normals orientation. All normals should point to DEM material 5

6 Problem Data: General Problem Data Assign File text associated to the GiD model 3 4. The Problem Dimension is fixed. Rock Cutting Disc simulation has only sense in 3D. The DOF is fixed as 6 3. This is the final simulation time 4. The user can define the Time Step, but the Automatic option is recommended 6

7 Layers: Available Options Three different layers have been created: Central point of the Disc Rock Cutting Disc Example of Layers managing. Create a new layer. Create a new folder with one layer inside 3. Delete the selected layers 4. Send entities to selected layer 5. Color of the layer Activate / Desactivate layer. It shows the layer entities Freeze / Unfreeze layer. It doesn t allow to modify the entities frozen 7 Push finish button to complete the entities transfer to the selected Layer

8 Element Types:Discrete, Finite Elements and Rigid Walls Assignation Disc 3. Discrete elements: Rock. Finite elements Tetrahedra: Disc 3. To save computational time and if Disc behavior is not important, the Disc surfaces can be meshed as Rigid Walls 8

9 Curves: Loads and Velocities Curves Definition Lineal Sinoidal. There are three different kinds of curves. The user can add pairs of Time-Value points or copy the columns from an external file 3. These curves are used for the velocities and loads description By Points 9

10 Mesh Properties: DEM and FEM meshes Assignation 3. Assign DEM to Rock. Assign FEM to Disc 3. This table is actualized automatically and shows the Mesh Type and which Layers have that Mesh Type 0

11 Materials: DEM Materials Assignation. Available material models

12 Materials: DEM Materials Assignation

13 Materials: Draw Assigned Materials. To Draw all the model materials in colors, the user has to open the materials definition window 3

14 Kinematics Conditions: DOF Restrictions Assignment. In 3D, the Fixed DOF condition can be assigned to Points, Lines, Surfaces or Volumes. The DEM condition is assigned to the base surface of the Rock. 4

15 Kinematics Conditions: DOF Restrictions Assignment. In 3D, the Fixed DOF condition can be assigned to Points, Lines, Surfaces or Volumes. The FEM condition is assigned to the Disc Central node. The rest of the Disc will be defined as Slave 5

16 Kinematics Conditions: Master Node and Rotation Movement Assignment 3. The condition is assigned to the Disc Centre. There is not any Initial Velocity in this model 3. The Initial Conditons visualization is available only in Points 6

17 Kinematics Conditions: Master Node and Rotation Movement Assignment. The condition is assigned to the Disc Centre. There is not any DEM Prescribed Velocity in this model 3. The Curve selected is the defined in Curves Definition step 7

18 Kinematics Conditions: Master Node Assignment 3. This is not an assignation button, it only selects the Master node. To assign the condition the user has to push the Assign button. The Master Point is the Centre of the Disc 3. There are available all the model layers: Disc, CentreDisc and Rock 8

19 Contacts: Creation and Parameters Assignment. Name of the Contact automatically defined with the form: MasterLayer-SlaveLayer. Bounding box is automatically defined, but can be modified by the user 3. To Delete one pair contact 9 3

20 Loads: Gravity and External Loads Assign Gravity Direction. This model has no External Loads 0

21 Concentrated Mass: Equivalent Mass and Inertia Assignment. The center node has not material properties and it needs mass and inertia in order to be integrated in the calculations

22 Damping: Mode Selection and Assign 3 3. The damping force is proportional to the velocity. The damping force is proportional to the acceleration 3. A detailed description of the parameters is shown in DEMPack handbook

23 Mesh Generation: DEM Parameters Mesher and FEM Assign Sizes. The Sphere mesher options parameters could vary depending on the model requests. This is the desired DEM spheres diameter 3 Push Esc button to assign element size

24 Mesh Generation: DEM Assign Sizes. Select the volumes of the Disc. The Master surface will be repeated in structured direction selected after 4

25 Mesh Generation: DEM Assign Sizes Number of divisions per line. Select one line in radial direction of each volume. The Master surface must be meshed 5

26 Mesh Generation: View Mesh Options. This value is only useful for the surfaces with no previous element size assignment. Render visualization mode 6

27 Mesh Quality Options. DEM radius distribution. Tetrahedra minimum edge distribution 7

28 PostProcess Options 3. This is the interval time between two simulation results. This time must be proportionally to the final time. This is the total number of simulation results in the simulation 3. The Displacement Output is always selected 4. The other Outputs selected will be shown in the simulation postprocess 8

29 Calculate: Process Info and Results Control. Before Calculate the model the user should save it. During the model calculation the user can see the results through the postprocess button 9