SolidWorks Simulation is a tool that engineers use on a daily basis. SolidWorks does a great job of breaking the Finite Element Method down into a easy to use interface that any engineer can use. All that is needed is some basic setup to define your loads, restraints, and contact types and SolidWorks will give you back results that can ensure an optimal design.
SolidWorks can make this so simple that we sometimes take for granted what it does behind the scenes; things that other simulation software requires us to know in advance. Because of this, I thought it would be interesting to take a look under the hood of SolidWorks Simulation and see how the theory behind beam elements in the Finite Element Method is used to solve your everday problems in SolidWorks.
The example we're going to look at is the cantilever beam shown below. In the problem, we are going to solve for the displacements and reaction forces at the fixed wall. Now I realize this is a simplified example but this same theory is applied to every element in your mesh when working with a more complex beam model.
The solution to this problem involves using the general stiffness matrix for beam elements and applying it to each element in the problem; in this case we are only using two elements. The two element stiffness matrices can then be combined into one global stiffness matrix which can be used along with Hook's law and some initial boundary conditions to solve for the displacements at each node. Once the displacements are known, back substitution can be used to find the reaction forces at the wall. The step-by-step solution to this problem can be found here.
Now shifting gears into SolidWorks, we will see how this same theory is used by the software to give us the desired displacements. The screenshot below shows how the setup in SolidWorks matches our initial problem.
Normally best practice while using simulation is to break each of these beams up into multiple elements. For the illustrations purposes, I have reduced this model into a two element problem to be consistent with the hand calculations. Further refining the mesh however would not change the results.
Hopefully seeing this simple example will give you some confidence in the results you are getting for your own applications. I know for me it is easy to look at the complex things that SolidWorks does and think of it as a big black box that just spits out a number but there truly is reasoning behind the results that are seen.
For more interesting theory behind SolidWorks Simulation, see our post on FEA and The Theory of the Universe!