If you have a large model, it is impractical (and perhaps impossible) to apply a high-fidelity mesh to the entire model. However, without a high-fidelity mesh, we will miss detailed information on what is happening in the fillet region shown in the submodel on the right. A breakout model can help you look at the subsection and see where the stresses are, see if that fillet is structurally sufficient, and generally give you more information.
When a small design change requires analysis.
When a small portion of a large design needs to be iteratively designed - You don’t want to have to run your large analysis model over and over again. Instead, you can iterate the submodel and save computation time on the solution
When a feature is added to an existing part - In our first example, we will look at a scenario where avionics wants to add a pass-through to a wing-rib. It will be computationally expensive to run the entire model just to analyze the new mesh on the rib, so a breakout model would be useful.
When examination of localized stress risers is needed.
Let’s look at some examples of situations where breakout modeling can be used.
Small Design Change Example
In this first example, assume that avionics asked you to add a pass-through to a wing rib.
Here is our full wing model:
And here is the rib that we want to add a pass-through to:
In Femap we can easily isolate the rib, add the pass-through, and interactively apply a new mesh to the rib: