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Re: Model is Unstable, restraints inadequate.
I was able to solve just as you sent it. Here are the key settings, your defaults may be different?
Solidworks Simulation 2015 SP1.1
Properties -> Incompatible Bonding Options -> More Accurate (Slower)
Direct Sparse Solver
66 Joints calculated in the Dialog Box
Default mesh
Try recalculating the joints with different options.
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Re: Model is Unstable, restraints inadequate.
I am using Solidworks Simulation 2010 SP0.0. I on have an option for simplified bonding contact. Using direct sparse solver. 66 joints calculated. Don't see an option for default mesh. See attached picture.
I appreciate your help, I am relatively new to this.
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Re: Model is Unstable, restraints inadequate.
This is what the model looks like when I just click create mesh. :/
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Re: Model is Unstable, restraints inadequate.
Unfortunately I never had much success with beams/joints until around SW 2010 and probably a later Service Pack. That feature has matured quite a bit.
I do recall having to do "Edit Joints" and experiment until it was able to connect everything. There can't be any errors or warnings in the joint group otherwise it can't continue.
I'm new to this forum and haven't figured out how to quickly paste images directly from clipboard (without saving first). I'll try to post some images of the solved model.
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Re: Model is Unstable, restraints inadequate.
use a frequency analysis to figure out where beams aren't connecting to each other
this looks like a mini baja or fsae project, i'd highly recommend moving to the latest version of SWX as it is better at handling the joints than 2010
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Re: Model is Unstable, restraints inadequate.
Trying to run a frequency analysis and got an error for singular matrix... Its a 4 seater offroad buggy, like ultra 4 style.
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Re: Model is Unstable, restraints inadequate.
that means you most likely have beams that are completely disconnected
you'll need to isolate them manually to figure out which aren't connected
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Re: Model is Unstable, restraints inadequate.
This is a plot of the displacement. You've done everything right. I think the version of SW Simulation you have may not be as beam-friendly as later versions (2010++).
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Re: Model is Unstable, restraints inadequate.
yea. Thats exactly what it is. I went to my bosses computer who has 2014, worked perfectly fine. Strange.
Now if only I understood the numbers better. Is there a good write up anywhere on how much force you should use and reading the data?
WIth 8000lb on the side I only get like 1/8" max deflection if I'm reading that right, but the FOS scale is like .25 or something. That doesn't make sense to me. If I come out of a hard roll and side bar only moves 1/8", that's great in my book.
KRis
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Re: Model is Unstable, restraints inadequate.
What that is saying that it would deflect 1/8"... IF the bars were all strong enough. It calculates deflection based on stiffness without taking into account the strength. Then based on deflection it calculates strain and based on strain it calculates stress.
Your FS<1 indicates that some bars will fail (my guess would be the 2 vertical supports for the middle of the cage). If you eliminate the bars that fail from the simulation and run it again you will likely see higher deflections. Simulation won't change the model partway through which is what truly happens when certain members fail and the load paths change as a result.
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