JohnM

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JohnM
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  • Solidworks is not any better at retaining face numbering. We can reload CAD and maintain surfaces for things like tolerance studies, but as you say, remove a fillet and it's square one. Possible cheats: If you are re-working one part, try and set …
  • I think I've posted this before, but couldn't find it, so here it is (again I think): Think small - small models, small time steps. Model sizes can grow after things start making sense. Very stiff models are hard to run/converge. Run a modal anal…
  • FYI, here is what I am currently do that works but is a pain to implement: -I set the modulus of the component of interest very high and re-run. -I dump displacements for the "real" and "stiff" cases. -I take the difference between these cases and …
  • FYI, here is what I am currently do that works but is a pain to implement: -I set the modulus of the component of interest very high and re-run. -I dump displacements for the "real" and "stiff" cases. -I take the difference between these cases and …
  • Thanks for looking at this @fatmac!
  • Thanks for looking at this @disla!
  • For what it's worth, I clicked "mesh" with 20mm element size, set steel and a wall thickness to 5mm?, held the bottom, loaded the top and the thing looks like it's behaving. If you took the time to modify wall thicknesses and put the correct load in…
  • Mesh the whole thing, then select just the surface you want to keep in the Geometry section and select "add surfaces to new named selection". Select that named selection and switch to element select, then add elements to new named selection. Delete …
  • Silly us for not noticing back in January, Congratulations! I for one am very glad you put this together, it's been an awesome ride.
  • I second the Optimax method, it does a nice job finding the coefficients.
  • For the range of loading we typical use, I find the Mooney Rivlin materials tend to stiffen with load, as shown below. I attached a file with hyper55a properties, you can run this and see the behavior.
  • #copies would be a good addition, in the mean time, I do 2 things: 1 - extrude the edge, as others have said or 2 - make 10 copies, then make 7 copies of my "10copy set". at least there's lot less clicking! extrusion example:
  • My favorite thing about this forum is some of the small discoveries I make with the gems that get offered up in conversation - like Node coordinates cylindrical, brilliant, and right in front of me!
  • My 2 cents. CCX, nonlinear 3D, note settings in Analysis. I used a handy hyperelastic material but your hyperfoam should perform similarly. I ramped your Y displacement, and removed the constraint on the pin surface - if it can slide, it can move n…
  • @fatmac I thought of that exact idea but dismissed it because I thought it was a dumb idea. apparently not! thanks
  • My spring is in need of pre-tension, and I am not finding a way to do this. When I have a spring connected to ground, I can "pull" the ground side to put in pre-tension, but if the spring connects two parts, I am out of ideas. Is there a custom mode…
  • Make sure your model has no unused nodes!
  • @disla the Mecway example is using the CCX thermal pipe elements. The input for these (as I use them) is the mass flow and capacitance while the surface they are connected to has a user-specified heat transfer coefficient. The usefulness of this me…
  • I changed your model to quasi-static and ramped the 18MPa load. I cheated by putting some "rubber bands" (elastic support) on the nut plate to keep things from flying away in the first steps. This is a good trick so long as you remember to use Solu…
  • Look at FreeCAD for this, it has the functions you need and works quite well.
  • @kuhtip I think what you are discovering here is not just how to set up a bolted connection but also the "killer app" to Mecway - the users in this forum We have been using Mecway for 8 years now, with many licenses. Rest assured you have chosen w…
  • set your solver to CCX, Nonlinear 3D, the option should appear.
  • Temperature contours on my pipe elements! Edge selection also rocks, thanks for V23!
  • We have come to accept that there is a flattening at around 8 cores. We set up computers in this range. I think there is always a tradeoff between cores and "share time" between cores. This will be problem specific, so you may find success with a p…
  • Don't read too much into the geometry creation, the Simcommons models are all built to run in under 1000 nodes. When I was in the gas turbine industry, we would work hard to keep the element count down but accurate enough to capture those higher mod…
  • @pberry yes, skip to after the dummy geometry creation and you'll see the cyclic symmetry setup. Not hard to set up, but spend and entire career understanding
  • The 'needs a thickness" likely means the mesher only got through the surface meshing. I would try and identify where the mesh is struggling and see if you can improve the CAD Sometimes it is one little blend that makes it choke. You would not wan…
  • Use the Pastix solver, available pre-compiled on the Calculix website ( the "files" link). Link to the ccx_dynamic.exe executable. You can use the CCX solver switch to change to Pardiso if necessary.
  • I see some that I asked for, I like others I didn't, thanks for the updates!
    in Version 22 Comment by JohnM October 2023
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