FEA Used to Optimize Load-Bearing Components
ALGOR’s InCAD technology provides direct CAD/CAE data exchange and full associativity with each design change for Autodesk Inventor, which Morton uses when modeling the load-bearing components. Some of the components Triple Eight has optimized include the front upright, damper top mount, upper and lower engine mounts and front anti-roll bar blade.
“In our stress analysis work, we often need to analyze many different iterations of the same part very rapidly,” said Morton. “When working with tight deadlines, the more quickly these iterations can be performed, the more optimized the part will be. The steps that ALGOR has made with full associativity furthers our efficiency and the final quality of each design.”
The front upright is the part into which the front axle is fitted and onto which all of the front suspension linkages, dampers and brakes mount. Loads induced by lateral acceleration and in-line deceleration can be up to 2g for a vehicle weighing up to 1,216 kg. The main criteria for analysis are strength and stiffness. “This is arguably the most important component of the car, as it defines the front suspension geometry and the dynamic behavior of the wheel,” said Morton. “Obviously, no failure due to stress can be accepted. In addition, any deflection incurred in service is undamped and can reduce grip and controllability.” FEA was used to increase the stiffness by 16% while adding only 4% more weight.
The damper top mount attaches the damper to the chassis and absorbs all of the vertical loads created by the front suspension. “It is imperative that this part be as stiff as possible as it is loaded directly by the damper and any undamped deflection will have an adverse effect on traction,” said Morton. “It is also, of course, analyzed for strength but with a higher factor of safety to counter the effects of the oscillating load.” FEA was used to increase the stiffness by 3% while reducing the weight by 24%.
The upper engine mount supports the engine and gearbox assembly that weighs close to 200 kg and is subject to harsh conditions induced by acceleration because it is rigidly mounted. “This part is one of the first parts we analyzed with ALGOR and we ended up designing it in a way that we had never thought would withstand the loads,” said Morton. “As a result of design optimization, the new upper engine mount design is significantly lighter. FEA was used to reduce the weight by 38% while decreasing the stiffness by only 4%.”
The lower engine mount also supports the engine and gearbox assembly and has to withstand lateral suspension loads. “Both strength and stiffness are of utmost importance as the lateral loads from the tire are reacted directly through this part,” said Morton. “A well-designed lower engine mount enables the front of the car to absorb lateral loads with very little deflection.” FEA was used to strengthen this component by 75% while adding only 21% more weight.
Unlike most other car parts, the front anti-roll bar blade is far stiffer in bending along one axis than the other, so the stiffness of the anti-roll bar assembly can be reduced with a very quick alteration. “This part is highly loaded as it transfers vertical input from the front suspension through curb-strikes across the car,” explained Morton. FEA was used to increase the strength of this part by 12% while maintaining the same weight.
Always looking to the next race and the next round of improvements, Triple Eight is already planning to use additional analysis tools from ALGOR. “Our next ventures in analysis will include Mechanical Event Simulation and linear dynamic analysis to enable us to analyze parts with an accurate load cycle,” said Morton. “By allowing us to replicate the linkages and assemblies that contribute to the loading of each part, we hope to use these analysis tools to understand more about the dynamic behavior of the car.”
As Morton continues to integrate different types of analysis into Triple Eight’s design process, he is utilizing ALGOR’s service and support. “The support provided by ALGOR is second to none and the response is always rapid and informative,” said Morton. “ALGOR’s use of Webcasting as a method of communication displays ALGOR’s drive to grasp new technology and adapt it for the use of their customers. It is this attitude that we are continuing to make the most of in our partnership with ALGOR.”