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Victor
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Comments
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You're quite right @Mishal I used that term a bit sloppily. Even a simple sin(theta)=theta pendulum won't work.
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Hello szicsa Mecway can't model general surface-to-surface convection or radiation so you would have to model it as an equivalent conduction through a layer of material. If you use the CCX solver, you can connect them with contact and define a the…
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You need to use the Nonlinear dynamic response 3D analysis type for this because of the large rotation. Just change that and set solver to CCX and it works. EDIT: Also add a Z constraint at the pivot for 3D. Pardiso can solve without that but Spool…
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Hello Vinicius_Petrucci. If I understand correctly, you can use contact with the unilateral option to allow sliding and separation. If you want sliding without allowing separation, maybe bonded contact with a near-zero tangential stiffness. It's OK…
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There isn't a general way to input a pressure field. Some alternatives: If the x,y,z values correspond to nodes or elements in the mesh, you could write a Python script or use a spreadsheet, perhaps with face node coordinates obtained from Solution…
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Yea it's a confusing word, also called bubble functions. I don't fully understand what it means but the "I" in C3D8I stands for incompatible too. So CCX has both types. I agree with the principle of just updating the formulation instead of adding a…
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They are hex8 elements but using the standard formulation from textbooks which is over-stiff in bending so it requires a fine mesh through the thickness so that each individual element hardly bends much. Yes, you can use the incompatible type with …
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The mesh is too coarse. Refine x2 leads to 19 MPa and 10 mm deflection. Generally, you shouldn't use the linear elements, especially in bending because they're terrible like this. However, the next version of Mecway will have incompatible mode hex8…
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For last iterations, add a Modify keyword item to the CCX branch with keyword *NODE FILE, parameter name LAST ITERATIONS and no value. However, I notice the .frd file it generates can't be read by Mecway. You can open it in Prepomax though. For the…
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Sorry about the crash. It should have left behind the temporary folder with the CCX solution in a .frd file you can open. It would prompt you about this next time you started Mecway.
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I don't understand the black lines problems but in case they are the edges of solid expanded beam elements, you can turn that off by requesting axial force in the solution and it outputs line elements for beams. They'll still have uncolored parts wh…
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With quasi-static, you have to ramp the loads yourself (eg. "123 * t" for linear ramping or "123 * t^2" for gentler quadratic ramping), otherwise they're immediately on which is bad for convergence. Is it saying there are too many increments? If yo…
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Oh cracks opening makes sense why it would be slow. What are you using as a material model? If the stress-strain curve has a sharp knee in it, that's certainly something it can struggle with. It sounds like you might not be using quasi-static. I wo…
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Lots of possible reasons, especially if there's contact, rotations of 90 degrees or more, or if it's buckling or has plastic material. Could you attach the file or email it to me privately?
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I don't know any good reason. Probably I wasn't confident in how to validate it (should it also cause a Coriolis force?) and not many people asked for it.
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No mouse rotation, sorry.
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Yes. Mesh tools -> Move/copy and Rotate/copy do that. You can also translate by dragging one of the selected nodes with the mouse and snapping it to another node to move the whole part.
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Yes, that should be OK if you're just looking for stress over one cycle. Use: Analysis settings: - CCX - Nonlinear Static 3D - Quasi-static Meshing parameters: - Maximum element size 30 mm works but the default doesn't. Support with Node-surface …
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Have you tried with Gmsh? It tend to be better at this than Netgen.
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@disla, I seem to remember you found some problems with very high strains in linear materials before? Although that's usually physically unrealistic, in this case, the mechanical strain is near zero so I'd say it should be a reasonable approach. M…
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Wow. I never knew there was any way to get rotational DOFs in equations! It's a bit of a pity that you have to keep one unused to put the dummy constraint on so it probably can't really be done automatically, but excellent discovery nonetheless!
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While/after it's solving, click Details in the solver pane, then Open working directory and the .frd file is in there.
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It might be too complicated. I'm trying to reduce it to the core problem (attached). I noticed that it does sort of solve if you add a "no extra contact step" in the CCX branch of the outline tree. The film is still flapping around but it's winding…
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Which element it chooses isn't defined, sorry. It might be highest or lowest element numbers but might change in future. I do have to sort out that selecting hidden elements problem though.
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You can put a dummy element like a zero-stiffness spring on that node so CCX includes it in the solution.
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It seems like you can't have the master and slave directly opposite each other. My guess is it might see that as penetration and try to push them apart. All I can think of is to make 2 or 3 separate contacts in repeating stripes so the master for o…
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It solved with the dent in the larger plate flattened out (set to y=0). I wonder if there's buckling happening around there leading to poor/no convergence. Is this something you're expecting or want to capture? With the dent in place, it solved a l…
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Versions 24 and 25 install ccx/ccx_win64_mkl_pardiso_source_2.21.zip (numbers instead of xx) in the application's installation location. Compiling that produces both the ccx.exe distributed with that version of Mecway, and ccx_mkl.exe which is the s…
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It's possible that turning off mixed precision (PASTIX_MIXED_PRECISION=0) takes away all the speed benefits of PastiX. I hadn't checked that. If you don't set it, it'll probably be faster but there's a risk of wrong results in some cases. A lot of …
