Swingarm analysis
Swingarm analysis
(OP)
hello,
I am working on doing this analysis of a swing arm, which is the rear suspension of a vehicle shown below. I am trying to simulate a worst case scenerio for a FEA which would be the vehicle falling and landing on just the rear wheels.
Im not quite sure how to calculate the loads that it will see, but I put the assembly in Solidworks Motion works and applied a rotational acceleration to see what the loads would be where the shock/damper attach.
What I don't are how to calculate what acceleration the swing arm would see in the above scenerio, and after I have the forces from the shock/damper at the swingarm, should I place the swingarm in an FEA constrain the rear where the wheels would be and apply the forces from Motion Works? Any info is appreciated.

Thanks,
Peter Ruggiero
I am working on doing this analysis of a swing arm, which is the rear suspension of a vehicle shown below. I am trying to simulate a worst case scenerio for a FEA which would be the vehicle falling and landing on just the rear wheels.
Im not quite sure how to calculate the loads that it will see, but I put the assembly in Solidworks Motion works and applied a rotational acceleration to see what the loads would be where the shock/damper attach.
What I don't are how to calculate what acceleration the swing arm would see in the above scenerio, and after I have the forces from the shock/damper at the swingarm, should I place the swingarm in an FEA constrain the rear where the wheels would be and apply the forces from Motion Works? Any info is appreciated.

Thanks,
Peter Ruggiero





RE: Swingarm analysis
Cheers
Greg Locock
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RE: Swingarm analysis
thank you,
pete
RE: Swingarm analysis
as far as I understand it, this is a typical case of "crash test". You could calculate the impulse force knowing the mass of the vehicle falling and the acceleration, but I seem to know that this accel is not really "g" but a greater one which takes into account the fact that the load is impulsive. Probably more expert people in this field will give you further details.
Regards
RE: Swingarm analysis
Establishing the maximum load you see in a suspension is a bit of a black art, several times the weight of the bike would be a good guess.
Cheers
Greg Locock
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RE: Swingarm analysis
RE: Swingarm analysis
Any book on simulating multi body dynamics would be a good start but I don't have one.
Cheers
Greg Locock
Please see FAQ731-376: Eng-Tips.com Forum Policies for tips on how to make the best use of Eng-Tips.
RE: Swingarm analysis
Garland E. Borowski, PE
Borowski Engineering & Analytical Services, Inc.
Lower Alabama SolidWorks Users Group
Magnitude The Finite Element Analysis Magazine for the Engineering Community
RE: Swingarm analysis
Thanks again
Pete
RE: Swingarm analysis
Cheers
Greg Locock
Please see FAQ731-376: Eng-Tips.com Forum Policies for tips on how to make the best use of Eng-Tips.
RE: Swingarm analysis
One caution: A drop test FEA is very dependent on the impact surface. Between the unmodeled tires and the fact that you may not be landing on an infinitely rigid impact surface will DRAMATICALLY affect your results. Generally, these packages offer some type of "impact surface" or "motion stop" that doesn't allow nodes to penetrate beyond a certain x-, y-, or z-value. If you are landing on thick concrete, probably not a bad assumption, but in the case of what I am picturing as a soil mechanics problem, your impact plane is likely no where NEAR infinitely rigid. You may be conservative with an infinitely rigid assumption, but you may also overdesign as a result.
Just a warning...
RE: Swingarm analysis
Cheers
Greg Locock
Please see FAQ731-376: Eng-Tips.com Forum Policies for tips on how to make the best use of Eng-Tips.
RE: Swingarm analysis
Kent Sawyer
RE: Swingarm analysis