Chassis Iterations

Chassis simulation method:

Initially, two possible methods of doing FEA on the chassis were considered:

1. Using beam elements lets Ansys know that it can solve each of the truss members as beam elements, as you may have learned in Statics. This dramatically reduces computational time while retaining the validity of the simulation.
2. Simulating the solidworks part would be ideal if we had unlimited computing power and time. If we were to directly evaluate the imported geometry in ansys, a highly complex mesh on each of the circular and round truss members would be generated, which is a waste of computational time, since each of the members is a simple beam element.

At the beginning the solidworks model was simulated. I set a symmetry condition to reduce the solve time by a factor of 2 and set the element size to  0.0245 inches, which is half of the thickness of the tubes. 34,554,115 nodes were generated which is way too complicated and time consuming.

Therefore in order to reduce computational time, beam elements were chosen.

Version	Picture	Description	Notes
1.0			-Trailing Arm clearance - Removing excess rear members -triangulation in the front not necessary to initial simulations (potentially revisit later) -Bend at top near driver head -Bring Side up
2.0		Removed the front crash structure -Added side bottom bracing -Curved front members -Raised posterior from B to C bracing -Removed rear bracing	Notes: -Remove extra bottom bracing -Lower Rear portion -Make back of car parallel to the rear seats to avoid interference and provide more room in the car -Add Curved front profiles -Add clearance about 13 mm for the bottom (structural aerobody) and about 10 mm for the top (non-structural aerobody)
3.0		-Made changes from v2.0 notes -Added horizontal bracing between the pillars to increase torsional stiffness and provide a rear seat mount -Middle bracing has two supporting members, each forming a triangle. This design is better than the rear member bracing because it better makes use of space and provides clearance for the catamaran. -The rear bracing is square to provide two potential mounting points for the trailing arms. -This bracing is within 10 mm of the top of the current aerobody catamaran -The rear is fairly undeveloped and needs some work.  Open to new ideas. Once we get some information about the trailing arm and how much clearance the tires need, it can be developed further -Changed tubing from 1.250 by 0.035 to 1.250 by 0.049 and material to 4130 steel