Mesh Control Workshop 3

Workshop Supplement Workshop 3 - Meshing Controls August 26, 2005 Inventory # WS3-2 Workshop 3 - Goals Use the various DS mesh controls to enhance the mesh for the crankshaft model. Problem statement: –The model consists of a Parasolid file representing a crankshaft for a small engine shown below. –Our goal is to mesh the model using all defaults and inspect the result. Next we will add mesh controls to modify the mesh in various regions of the model.

Workshop Supplement Workshop 3 - Meshing Controls August 26, 2005 Inventory # WS3-3 Workshop 3 - Assumptions Since this is a meshing exercise we will not be applying loads or solving the model. Instead we will assume a linear static structural analysis is to follow the meshing operation.

Workshop Supplement Workshop 3 - Meshing Controls August 26, 2005 Inventory # WS3-4 Workshop 3 - Start Page From the launcher start Simulation. Choose “Geometry > From File... “ and browse to the file “Crankshaft.x_t”. When DS starts, close the Template menu by clicking the ‘X’ in the corner of the window. Note: Although we could use the Simulation Wizard, the remaining workshops contain instructions on manual completion.

Workshop Supplement Workshop 3 - Meshing Controls August 26, 2005 Inventory # WS3-5 Workshop 3 - Basic Meshing 1.Highlight the mesh branch to view the mesh and access the meshing controls. 1

Workshop Supplement Workshop 3 - Meshing Controls August 26, 2005 Inventory # WS Workshop 3 - Basic Meshing 2.Inspect the mesh detail window. Notice the default global control is “Basic” and the “Relevance” is 0. Advanced mesh features are available as a licensed option. 3.RMB on the mesh branch and choose to “Preview Mesh”. 2 3

Workshop Supplement Workshop 3 - Meshing Controls August 26, 2005 Inventory # WS Workshop 3 - Basic Meshing The completed mesh (shown here) is made up of a relatively coarse tetrahedral mesh. 4.Expand the “Statistics” section of the details window to check the number of nodes and elements. Note the actual number of nodes and elements will vary slightly across different machines and platforms. 4

Workshop Supplement Workshop 3 - Meshing Controls August 26, 2005 Inventory # WS3-8 Workshop 3 – Mesh Relevance 5.In the detail window for the mesh change the “Relevance” to 50 (note: relevance may be set by dragging the slider bar or typing the desired value into the field). Again RMB the mesh branch and “Preview” the mesh. A visual inspection of the mesh along with the statistics section in the detail window can be used to compare the effects of the meshing changes. 5

Workshop Supplement Workshop 3 - Meshing Controls August 26, 2005 Inventory # WS3-9 Workshop 3 – Sizing Control We will assume the pin section (shown boxed at right) is an area of interest for us. We will apply a local mesh control in this region. We’ll take advantage of several shortcuts in DS to help us evaluate the appropriate size for the control.

Workshop Supplement Workshop 3 - Meshing Controls August 26, 2005 Inventory # WS Workshop 3 – Sizing Control First orient the model so we are viewing down the X axis as shown here. A handy shortcut to do this is to use the triad to re-orient the model. Clicking on any of the axes (or the “iso” ball) the triad will rotate the model accordingly.

Workshop Supplement Workshop 3 - Meshing Controls August 26, 2005 Inventory # WS Workshop 3 – Sizing Control Zoom into the area of interest. Notice the region is made up of 3 surfaces. To gauge the size of the region we can use the ruler tool (If the ruler is not displayed, use the ruler toggle at the top of the GUI to activate it). Inspection of the model shows the pin section is roughly 10 mm across.

Workshop Supplement Workshop 3 - Meshing Controls August 26, 2005 Inventory # WS Workshop 3 – Sizing Control 6.Select the 3 surfaces in the pin region. Note: by holding the CTRL key we can select each of the desired surfaces individually using left mouse clicks. An alternative shortcut called “paint selecting”, is to hold the left mouse button while dragging the cursor over the desired areas (no CTRL key necessary). 6

Workshop Supplement Workshop 3 - Meshing Controls August 26, 2005 Inventory # WS With the 3 surfaces selected choose “Sizing” from the mesh control menu. 8.In the detail for the size control change “Element Size” to 1 mm.... Workshop 3 – Sizing Control 7 8

Workshop Supplement Workshop 3 - Meshing Controls August 26, 2005 Inventory # WS3-14 Workshop 3 – Mesh Refinement Again “Preview Mesh” and inspect the new mesh as before. We will also assume the chamfer section on the side of the flywheel is also an area of interest.

Workshop Supplement Workshop 3 - Meshing Controls August 26, 2005 Inventory # WS Workshop 3 – Mesh Refinement 9.To apply the refinement control first select the chamfer surface. 10.Highlight the mesh branch and RMB. Choose “Insert > Refinement”. 9 10

Workshop Supplement Workshop 3 - Meshing Controls August 26, 2005 Inventory # WS Workshop 3 – Mesh Refinement Mesh refinement is an iterative meshing tool that can be set to integer values from 1 to 3. A value of 1 provides the least refinement (coarsest mesh) while a value of 3 provides the most refinement (finest mesh). Leave the refinement level set to 1 and again “Preview Mesh”.

Workshop Supplement Workshop 3 - Meshing Controls August 26, 2005 Inventory # WS3-17 Workshop 3 – Mapped Faces Finally we’ll apply a “Mapped Face Meshing” control to a surface in the model. Mapped face meshing is typically used in contact analyses to insure a “regular” mesh on the contact surface. High quality elements are often required when detailed contact results are desired. 11.Select the cylindrical surface shown here (either side of the part is OK). 11

Workshop Supplement Workshop 3 - Meshing Controls August 26, 2005 Inventory # WS Workshop 3 – Mapped Faces 12.Highlight the mesh branch and RMB. Choose “Insert > Mapped Face Meshing”. Again “Preview Mesh”. Mapped Face MeshDefault Mesh 12