Tutorial 1: Mill 2D. Mill

Transcription

1 Mill 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 Lifter 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. All normals should point to DEM material 4 5

5 Problem Data: General Problem Data Assign File text associated to the GiD model 3 4. The Problem Dimension is fixed. It has been defined by the user before. The DOF selection modifies other steps of the wizard interface. See Kinematics, Loads 3. This is the final simulation time 4. The user can define the Time Step, but the Automatic option is recommended 5

6 Layers: Available Options Three different layers have been created: Central point of the Mill Granular Material: which contains Sand and Grinding Elements Mill. 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 6. Activate / Desactivate layer. It shows the layer entities 7. Freeze / Unfreeze layer. It doesn t allow to modify the entities frozen 6

7 Element Types:Discrete, Finite Elements and Rigid Walls Assignation Mill Granular Material Granular Material Granular Material 3. Discrete elements: Granular Material and Grinding Elements. Finite elements Triangle: Mill 3. If Mill is non deformable, Rigid Walls must be assigned 7 Grinding Elements

8 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 8

9 Mesh Properties: DEM and FEM meshes Assignation 3. Assign DEM to Granular Material and Grinding Elements. Assign FEM to Mill 3. This table is automatically assigned and shows the Mesh Type and which Layers have that Mesh Type 9

10 Materials: DEM Materials Assignation Granular Material 0

11 Materials: DEM Materials Assignation Grinding Material

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 D, the Fixed DOF condition can be assigned to Points, Lines or Surfaces. The condition is assigned to the Mill Central node. The rest of the Mill will be defined as Slave 3. There is no DEM Fixed DOF in this model 4. There is no Initial Conditions in this model 4

15 Kinematics Conditions: Master Node and Rotation Movement Assignment. The condition is assigned to the Mill Centre. There is not any DEM Prescribed Velocity in this model 5

16 Kinematics Conditions: Master Node Assignment. This is not an assignation button, it only selects the Master node. To assign the condition the user has to push the Assign button. There are available all the model layers: Mill, Mill Centre, Granular Material 6

17 Contacts: Creation and Parameters Assignment 3. 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 7

18 Loads: Gravity and External Loads Assign Gravity Direction. This model has no External Loads 8

19 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 9

20 Mesh Generation: DEM Parameters Mesher and FEM Assign Sizes 3. The Sphere mesher options parameters could vary depending on the model requests. This is the desired FEM size 3. To really assign the element size the user has to select Esc and then push the Close button of the window 0

21 Mesh Generation: DEM Assign Sizes. The user has to define the diameter of the circles in each DEM mesh. The assignment procedure is the same as in definition of FEM element size

22 Mesh Generation: View Mesh Options. This value is only useful for the surfaces with no previous element size assignment

23 Mesh Quality Options A B A C B C D D 3

24 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 4

25 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 5