In this video, learn to create splits in the geometry surfaces to help guide FEA loads, boundary conditions, and mesh.
- [Instructor] We will now carry out the surface splitting actions required to prepare for the FEA loads, boundary conditions, and meshing actions. For the first task, I want to create splits to help carry the tensile bearing load, which extends over a 180-degree arc at the little end. Make sure we're in the Model tab, and we can see the geometry feature tree. Click on the side surface of the little end which is towards us. Click on the Sketch tab, and select Sketch from the dropdown.
Click on the origin point, the center of the little end. Click on Convert Entities. A new point is created, which is projected onto our sketch plane. Click on the line icon and select the center point as the start of the line. Drag the line up vertically until it's clear of the little end. Create a second point by dropping down vertically in a similar way.
Close the line properties form, and then close the sketch. Go to Insert > Curve > Split Line. Make sure the current sketch is shown in the selections box here. If it isn't, then open up the geometry feature tree and select the right sketch. Now select the four surfaces which enclose the little end's solid volume.
Make sure that the type of split is set as projection, and click the checkmark. We can see that the little end, let's go and look at that, we'll just turn the view, is divided up into surfaces ready to take the 180 degree bearing loading, which is going to be applied just over here. Now we want to repeat the exercise for the compressive loading. Click on the half-surface which we just created, which is towards us.
Click on the sketch icon to create a new sketch. Click the origin's center as before, and select Convert Entities. You see the new pointed created. Create two new vertical lines as before, so go to the line icon, pick the starting point, and drag vertically, and then offset it at roughly about 30 degrees from the vertical.
Do the same below. Check the line properties box. Create another curve from the same starting point. Drag this one up vertically. Check that as for construction only.
Create another vertical line dropping down below. Again, check that for construction only. Check on the line properties. Check Insert Line. Now we want to go to the Smart Dimension, and I want to create exactly 30 degrees between the vertical and the two angled lines. So click here, click here, and update this angle to 30 degrees.
Do the same below. From the vertical, select the roughly 30 degrees. We've got that fairly close there. So I've bait it to 30. Check that. So now we exit the sketch. We want to create another split. So again we go to choose Insert, Curve > Split Line. Again the active sketch is selected, which is great.
Now we want to choose the surfaces we're going to split, and these are going to be the four surfaces which enclose the little end. Let's use the little end view here. Spin it around. And the final surface inside.
Check the box. And now we can see we've got new split lines generated, ready to take the compressive loading. Now if we spin the model around and look carefully, just up here, in this view, let's zoom in, we can see we've actually made ourselves a bit of a problem because I've put a guiding split line here and a guiding split line here, which means that when they come to mesh, you're going to have very tiny elements forced to occur through here.
So that isn't a good approach. We need a different strategy here. The approach is going to be to use a plane of the fillet runout to create the split line. There will be a small variation from the 120-degree arc, but that's quite acceptable. So click on the icon in the feature tree, and edit the sketch. Delete the two smart dimensions.
Pick the two fillet edges, this one here, and the one below. Click on Convert Entities, and choose each one of these in turn, and make sure they're for construction, and they're for construction again. Let's just double-check that one.
Click that one. Again, hit For construction. Now I'm going to use the ends of these fillet runouts to force the split lines to go through there. So I click this split line and then hold down shift and click that point. I can then force a relationship to make them coincident. It snaps the split line to the end of the fillet.
We do the same thing below. We select that line, hold down shift, and select that point, and force the relationship to be coincident. So now the split lines have both been repositioned so they align with the fillet runouts. Click OK, exit the sketch, and now we can see that our split lines are contiguous with the end of the fillet runout, and that saves awkward meshing in this particular zone.
Now we're going to create a horizontal split line to help define the mesh. Select the front surface of the big end. Open up a new sketch as before. Select the center point of the little end. Click on Convert Entities. Now create two new horizontal lines running from this point, extending beyond the length of the conrod. So here's the first line. Pick up the end point. Run that horizontally.
Pick the second line. Pick the end point. Run that horizontally. Exit the sketch. Go to Insert > Curve > Split Line. The sketch is active. Pick the surfaces that we want to split. We can click and drag over the whole model here.
Now check OK. And we can see that we now have split surfaces which are going to help guide the mesh quite nicely through the structure. Now we save the model off. And we're going to call his baseline_5. So the geometry has been prepared for loads and boundary conditions and meshing by splitting the surfaces.
We could carry on splitting up the surfaces like this to aid the meshing further, but we'll leave it to this stage. You can experiment with different levels of mesh control using the geometry here.
- Setting up Simulation properties and defined views
- Preparing the geometry
- Setting up a local coordinate system
- Splitting surfaces
- Defining the constraint and the loads
- Running analysis
- Contour control
- XY plots