Working with Simulation in Solidworks

How do you make sure a bolted connection will model correctly in Solidworks?

Here are a few realizations I had about making sure a simulation of a bolted connection will run correctly:

1. Friction - Solidworks Help page says that friction is added automatically based on the materials chosen, but it isn't (note there is nowhere in material properties to add a coefficient of friction; it's based on both materials contacting, not just one). This means that every component contact must have a coefficient of friction set; if this varies, then multiple component contacts will be needed to fully define the model
2. Solver - The Solver matters; different solvers are better at different things. Most notably, the Direct Sparse Solver, while being potentially less accurate than the Iterative Solver, can better make use of powerful multi-threaded CPU's (such as the 32-thread Xeon in the Watkins Hall computer lab)

Solving With 'FFEPlus' Iterative Solver - Note 3% overall usage and one core used

Solving with 'Intel Direct Sparse' - Note 39% overall usage and most cores used

3. Washers on Bolted Connections - Washers are commonly used on bolted connections to avoid preload loss at the head or nut of a bolt due to deformation when the contact stress deforms the material where the head/nut presses. However, after reading about their use in bolted connections in Solidworks, I don't think it is necessary to add washers in the simulation, and it has the tendency to make the simulation not actually solve. It seems best, then, to leave washers out (maybe adjust the radius of the head and/or nut, I'm not sure how that works, I'm going to check that out next).

Update: Bolt head size does work in Solidworks Simulation

After testing the same model with a larger bolt head, it would seem Solidworks does in fact model the size of the bolt head (why would they let the user define the bolt head/nut size if they didn't?). This means that the user can use a larger bolt head to model a washer of the same size. Proof shown below:

Joint Model with 12mm Bolt Head - Note the lighter sections (more stress) around the bolt 

Identical Joint Model with 20mm Bolt Head - Note the area around the bolt is now light blue - lower contact stress