Beam elements is a powerful tool within ANSYS Workbench that converts a complicated tube/bar structure into a set of "beams" for analysis. This simplifies the mathematical model by treating each member of the part as a simple beam under load, and greatly decreases solve times. Note that beam elements is best suited for space-frame structures, like a vehicle chassis.
These steps were written for ANSYS 17.1 - the process should remain similar in more recent version of ANSYS.
Reference Geometry
In solidworks, create a 3D sketch of the chassis, with only line elements. Save the solidworks as an IGES file. When saving an IGES file, open up "OPTIONS" and make sure that "Export Sketch Entities" is selected, other wise you will be unable to save the 3D sketch as an IGES file.
In ANSYS, on a study, right click on GEOMETRY and select "IMPORT GEOMETRY" and import the IGES file.
Right Click on Geometry and click on "Edit Geometry in DesignModeler".
After opening up the design modeler, click on the "import" element in the design tree. In the details view, scroll down to the "Line Bodies" field and set it to yes. Afterwards right click on the import element and click "generate".
Now you should have the 3D sketch imported and showing in the Design Modeler.
Creating Tube Profiles
Under "CONCEPT" in the menu, mouse over to "CROSS SECTION" and select the type of element you would like to create. For our purposes we are using "circular tube" and "rectangular tube".
After you have added the cross sections, under "CROSS SECTIONS" in the design tree, click on the tube profiles to define the tube sizes.
Assigning Tube Profiles to Bodies
in the design tree, select an individual element. In the details, under the cross section field, select the cross section profile you would like to set the element to.
Creating a Multi-Body Part
To create a multi-body part, highlight all the line bodies in the design tree, right click, and select "Form New Part".
After all the bodies are added to the new part, mouse over "Tools" and click on "Unfreeze".
With the "Unfreeze" select all the line bodies of the most common tube profile, and press apply. What the unfreeze does is combine all of the selected line bodies, and combines them into a single body. The reason why you have to add the unfreeze is because ANSYS has a very difficult time simulating a multi-body part, with little to no additional constraint, contact region definition or joint definition. If a part has too many different bodies, ANSYS will just return an error message when ever you try to calculate results.