FSAE SUSPENSION PDF
REQUIREMENT FOR THE DEGREE OF. BACHELOR OF SCIENCE. IN. MECHANICAL ENGINEERING. FSAE Chassis and Suspension. Hello forum. I’m fairly new to FSAE and suspension design. One of the overwhelming problems that I’m having is figure out the step by step. This article deals with design of Formula SAE Suspension by considering various loads and their simulation on each component of the system.
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They have Formula SAE cars and course already modeled into the software. It has to be taken into account that the model is only considering the roll behavior for the skidpad, consequently the roll stiffness is represented only by springs and the damping is suited for the roll behavior of the car; in the real world you have anti roll bars to get different stiffness in bump and roll, and usually the damping is the same in roll and bump, then it has to be a compromise to suit two different stiffness ie roll and bump.
Hello Benn, First warm greetings and afterward; I’m a beginner too so don’t take this as an expert talk As in any design problem there are some step you should take before jumping into the details. I’m fairly new to FSAE and suspension design.
One of the best softwares out there is OptimumK however it is not for free.
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Know why before knowing how!! Note that the input in this case is cyclic. In the skid pad the difference between the two configurations is very subtle because of the fact that in steady state is the stiffness distribution, which is the same, that gives you some difference.
It would be interesting to investigate further to see how much is the influence of a different stiffness distribution configuration. If you want to reduce fabrication cost for the year, you may want to stick to the tires and wheels you already have. It’s skipped forward to the final 5. God be with you and Good luck with your design. Use the Bicycle model first for practice, then build to a Four Wheel 2D model.
This will also have to integrate with the kind of car you want to build overall tradeoffs aren’t the same with a 4cylinder than with a single, aero or non aero.
Then, build, race, win.
Suspension Design Step by Step Process
Below are represented the inputs used to evaluate the dynamic response with different configuration of spring and dampers. It should be very helpful too. The sine is used to represent road perturbations, depending on the frequency and the amplitude it could be roughness of the asphalt or vsae more severe pattern like circuit kerbs, as in our case. Get the basics right first, the details only after.
Analysis of a FSAE suspension system
The more times you go around the cycle the more you learn, the better your analysis gets and the more engineering you have in your design. Results 1 to 10 of In fact with softer spring on the front the difference is a little higher, but in every skid pad simulation the grip limits of the car are NOT reached, and consequently, as is evident in the yaw acceleration graphs, the car remains neutral. The bracket joint during the dynamic response simulation is removed to have the correct behavior fsaw the suspended and suspendion suspended mass system.
One thing that can be noticed is actually how bumpy the track is. One of the overwhelming problems that I’m having is figure out the step by step process in designing the suspension system.
Introduce yourself properly; namecountry, team C1 Hard spring and low damping coefficient: User Name Remember Me? You will have to make basic assumptions to estimate the values. Response to the sine function: What do you want to achieve?
A kerb or a cone hit at speed is a good approximation of a step input. The step input has been used to find out the two best configurations amongst the possibilities and to present only the most relevant and useful results for the other inputs.
I hope I haven’t said something stupid, if so I duly apologize.
Thanks for the information! How far up the helix can you get in your FSAE tenure? Secondly; Start by tires There is a knowledge-analysis-design- evaluate cycle The tire forces are modeled with a simple tire model with the following parameters: Here we can see the relative speed and angular speed that stabilizes after some laps, and the results are considered only for the stabilized part of the steady state corner.
Work well on the compromises Or find the yaw moment when both external tires are at peak for different radius. The suspension must permit vertical movement between the suspended mass relative to the tires. Now slim the ideas down to a core goal. An actuator moves the rack causing the front wheels to steer fsa desired angle. The frequencies for the chassis movement have been calculated with the linearization element and are from 3.
Suepension we can see that the relative speeds in red the longitudinal component of the chassis stabilizes in the second part of the simulation. Only then will you have to worry with roll centers, roll stiffness, kinematics, motion ratio, dampers and such things.
If tires change, what becomes different. Then; Put the whole geometry on a kinematics analysis software Detail of the CAD front right wheel assembly view from the inside of the car.
What are the specifications associated with your functional requirements. If you have aero you have to calculate the load from it, in any case you will have drag, wich will require torque from the rear wheel and will create suspwnsion small load transfer!
You won’t be able to be sure about the results unless you have tire data! Start by 2D visualizing.