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Why do I keep getting pivot solver errors?

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    • IForsyth
      Subscriber

      Hey guys, I have been running into a brick wall for weeks with my simulations. I'm working on a chassis and originally I was able to run my simulations on the lower ladder with ease, but after adding in the other members I've had issues with meshing or pivot solver errors when trying to solve. I've finally got it all in a beam model but am encountering pivot solver errors still. I've tried replacing, moving, editing my forces and supports with no real success. Is anyone able to point me in the right direction to get this working?

    • peteroznewman
      Subscriber
      ArraynThe first diagnostic check on a Statics model that has solver pivot errors is to add a Modal analysis to the Model. You will immediately see in the Modal results that many beams are not connected. They float away from the adjacent beams they are supposed to be connected to.nZoom in on the lower beam that was shown in the first image above. You can see that the nodes of the longitudinal beams are not coincident with the nodes at the end of the transverse beam. That is required to have connectivity. You could add Bonded Contact to try to repair that mistake, but it would be much better to go back to SpaceClaim and break the longitudinal line into segments so there is a vertex at each transverse beam.nTo do that, use the Share button on the Workbench tab in SpaceClaim so those beams become connected.nRerun the Modal analysis and you will find there are still some beams that are not connected, such as this one:nThe gap between the vertex of one beam and the line of another beam was too large for the Share function to cross that gap. Go back and fix that.nYou can type in a 10 mm search distance in the Share function.nShare can't fix every problem. nDelete that beam, draw a curve that has an end that is coincident with another beam, and create a new beam, or you can use a Node Merge in Mechanical to move one node to the other.nFinally, a fully connected frame:nGood Luck!n
    • IForsyth
      Subscriber
      Thank you! This is exactly what I needed.n
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