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Modelling of bicycle suspension

Modelling of bicycle suspension

Modelling of bicycle suspension

(OP)
Hey,
so as part of my third year university project we have to design and build a folding bicycle, as part of this process we have to show some form of FEA analysis. I have done one module in abaqus that really didn't prepare me for what I needed to model a complete 3D FEA analysis and as such I have taught myself through what was available online and trial and error. I have now got a running model in place that gives results, however I feel that the deflection represented by the model is considerably larger than what it really ought to be.
Here is the frame before deformation is plotted: Link
And the frame after deformation is plotted: Link
The frame has been imported from solidworks in several parts and all interactions between parts should be correct. The spring itself is modelled as a 75mm 550 lbs/in spring mounted between two aluminium blocks to simulated a normal bicycle suspension spring.
Any help in this would be greatly appreciated and I apologize if this is not the correct way of showing screenshots on this forum, it's my first time posting.
Kind regards,
Adam

RE: Modelling of bicycle suspension

(OP)
Having just received my confirmation email I realize that my post is in violation of the students rule, however I am not some "lazy students posting homework", I have put about 60 hours into this and have hit a bit of a road block with what to do next in regards to more accurately modelling the spring and any help would be kindly received.
Kind regards,
Adam

RE: Modelling of bicycle suspension

Without more information here are a couple of guesses.

Do you have consistent units? Your spring definition was stated as "75mm 550 lbs/in"

When viewing results Abaqus can scale the deformation. Make sure it's set to 1 if you want to see the actual deformation.

I hope this helps.

Rob Stupplebeen
www.optimaldevice.com
https://sites.google.com/site/robertkstupplebeen/

RE: Modelling of bicycle suspension

looks like the viewer scaling is set to a number larger than 1, mentioned above.

RE: Modelling of bicycle suspension

As the others have mentioned, the deflection shown is exaggerated for easier viewing. If you look at your legend, your maximum deflection magnitude is less than 2 mm, which seems reasonable.

RE: Modelling of bicycle suspension

(OP)
Unit are all correct, i quoted them as that more because I had built the model in mm in solidworks, converted to meters in abaqus and the spring I'm trying to model is 550lb/in but I converted to N/m before entering, so many different units it's becoming difficult to keep on top of them all.
As for the viewer scaling, I wasn't aware if that was something that could be altered, as I mentioned I have been teaching myself through mostly trial and error so a lot of what is probably basic and silly things are over my head still. How would I go about changing the viewer scaling? I've looked through all the settings and can't seem to spot in anywhere.
Thanks for the quick responses.

RE: Modelling of bicycle suspension

Options->Common->Deformation Scaling Factor

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