In this video, learn to apply an effective mesh to solid geometry.
- [Instructor] Having seen the curvature base mesh control, we now look at the local mesh controls. Right mouse click on the mesh icon and choose create mesh. Now, change the options here, de-select curvature base mesh and go for standard mesh. Make sure the default is set automatic transition is set off. We go back to our global mesh size of .4 of an inch. We can also set the option, save settings without meshing. This will stop it re-meshing every time we change a parameter, so we click okay.
Now there's a warning triangle that appears against the mesh icon. That indicates that the model mesh is now into date compared to the latest mesh controls we've set up because we reset back from curvature, to standard meshing. I right mouse click on mesh and click on, applying mesh control. Let's go into the little end and I want to select the inner surface is an outer surface as the little end.
So, I pick these, you can see as I go, there are symbols indicating there's a local mesh control being applied to this. I picked the outer surfaces, now I want to set the element size to .2 of an inch.
Click okay, now the model has re-meshed because we switched off the automatic re-meshing. One of the things that I want to do here is to get rid of the icons, which has shown for the loads because they're getting in the way a little bit. So each of the loads, let me go and right mouse click and just say hide, hide and hide, that cleans up the plot a little bit. Let's go back to our mesh, we have the new mesh control called, control one.
Let's change that name to, little end bore. It's a good idea to keep a hand on these local controls by naming them because they're going to be very powerful. If we just have control one to control 10, we can't remember what is what. Right mouse click on mesh, choose create mesh and check to run.
I can see you've got a nice mesh now on the outside face and on the inside face. Retain elements across the width, we still only have two elements through depth, so we want to address that next. So again, we go down to mesh controls, right mouse click and say apply, mesh control. We're going to set up a new mesh control. Let's pick the services on the outside. Notice I've left a transition region here, I'm not controlling the mesh.
The same on the other side. I'm going to change this mesh control element size down to .1 of an inch. Now if you remember, .1 of an inch was the global mesh size we set up everywhere and that was a huge hit on a number of nodes. So here we're trying to localize that mesh density. Check the box here, again, it doesn't re-run because we have alternate mesh switched off. Let's go down to the mesh controls, can rename this one as little end side.
Right mouse click on mesh, say create mesh, okay to run. Now you can see we've got nice control on the outside and also, through depth, which is perhaps more important, we have five elements through depth. Let's experiment with these mesh controls so, go back to mesh controls, little end bore, let's edit that definition and let's change that down to .15.
Check, okay. Little end side, again, let's edit that definition and drop that down to .05. Check okay, I can right mouse click on mesh, create mesh, re-run that. We can see a final mesh everywhere now.
Let's just check the element quality. Right mouse click here on the aspect ratio, show that. It's sitting at 9.7, now it's handy to see where that is, there's a thing called the data probe. So let's right mouse click here, go to chart options, then we have an option in here to show maximum and minimum. Whatever the result quantity is and this is classified as a result quantity, we can apply these controls so share a minimum and share a maximum.
Check the box, now we can see very clearly, if we go to the standard view, the maximum is and they're all favorite down here, with the fill it run out. So let's go back to our standard view. If the mesh control icons again, get a little cluttered, what we can do is hide those, so right mouse click here, to say hide, right mouse click again and say hide, and again, we have a cleaner view.
Let's hide the aspect ratio plot for the moment, again remember, we have to re-invoke the mesh plot. Let's go to the little end region. Now, the mesh is looking pretty good, but the mesh transitions going in here, is perhaps a little too abrupt. So again, we can apply some controls to that. So let's create a new mesh control, right mouse click, apply mesh control, you're going to pick a transition region on this side and the transition region on that side.
Let's set the element size here to .15, check okay. Let's rename that mesh control as little end transition. Let's run that. To mesh, create mesh and now, run.
And now, we can see we have a better transition region running through there and we'll call it a day there for our mesh experimentation. Let's go and look to see how many elements we have and how many nodes we have, so right mouse click on mesh, go to details and we can see our node count is around about 70,000, total number of elements is around about 44,000. So we kept the element count down very nicely compared to the big numbers we had before, but we've been able to achieve very, very fine mesh in the areas we anticipate stress concentrations of being high.
Let's finally go back into mesh quality plot, check the aspect ratio and we can see 9.762. Again, with our max-min probe on now, let's go to the standard view, see where that is. And again, it's our favorite place down in here, it's the filet radius. Again, this is not a good element, it's collapsed, it hasn't totally collapsed but the aspect ratio, you can see it's very shallow compared to its length.
I'm going to accept that and if we look at the overall mesh quality, I'm going to say that's reasonable. My motivation for accepting it is because again, we've made a lot of compromises in the big end. We are going to be super gluing that down to the crank, we can assume that any results in this region are not going to be useful. We're going to be focusing on results in this region on the little end. Now we're going to save the model, as, con rod baseline number 11.
We want to copy the result files across again, these being the quality plot results. So in conclusion, the local mesh controls allow a sophisticated measuring strategy to be developed and also, experimented with. We've been able to create a mesh with a large number of elements, the region of highest stress concentration, with a very modest overall total node count.
- 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