- [Instructor] The requirements for planar symmetry
are that the geometry is symmetric about a plane,
the loading is symmetric about the same plane,
and finally the constraints are symmetric
about the same plane.
Now these are all true in our case.
The way that planar symmetry is enforced
is by applying boundary conditions to the faces.
So we go to the half symmetry study tab.
And we right mouse click on fixtures
and choose fixed geometry.
The faces we want to fix
are the three faces on the symmetry plane.
So we select these.
Now we go to the advanced settings.
And we select symmetry.
You can see a ghosted image
of the virtual half of the structure
below the symmetry plane.
This is very useful to check the center of the symmetry
has been applied properly.
You can also see an animation in the fixture type window
showing the action that we selected.
So check okay.
Behind the scenes constraints
have been applied in the Y direction
for stop motion of the half model across that plane.
We could've just used the fixed geometry option
and only select the Y direction
however the symmetry option is quicker,
also gives this nice visualization
of the intended symmetry plane.
It's important at this stage to realize
that the X and zed directions have not been constrained yet.
You click on the fixtures icon
and rename this as Y plane symmetry.
Now we want to constrain the big end
so we right mouse click again on fixtures,
choose fixed geometry,
this time we select the one half face, the big end.
Click okay.
Now we're going to apply the tensile load
only at the little end so let's zoom into the little end
using the little end view.
Right mouse click on external loads and select bearing load.
The entity we want to apply the loading to
is this face here.
In the coordinate system,
make sure we open up the geometry feature tree,
choose our coordinate system which is little end.
Make sure the units are in the English IPS system.
Now the total force applied to the little end
in the full model was 14,300 pound force.
Now we are only using a half model
so it literally split that load in half.
So we can enter in here 14300 which is the full model
and then on the fly we can simply divide that by two.
Let's just check the direction.
The direction looks like it's going the right way,
otherwise optionally we could've reversed the direction.
One final check is that
we have the sinusoidal bearing type distribution chosen,
we check okay, and loading has been applied.
So just summarizing, we've applied the bearing load,
we've also applied the symmetry constraint,
that only operates in the Y direction sense
but we have fully constrained the model
because we also applied the loads in the big end
and that's in the full X, Y, and zed directional sense.
For that point let's save them all off.
We'll save that as con rod advanced three.