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Victor
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Mecway's internal solver beam elements are only Euler beams which means they have to be slender as well as other limitations. Also, no shear stress output. In principle, CCX's expanded beams should be more accurate. However, they sometimes have weir…
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You can't do that in Mecway but it should be possible with your CAD software, at least joining the manifold edges. You can also install the Netgen app which has a tool to heal geometry. Other people have found it useful but I haven't used it myself.
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It's arbitrary. That's a good point that it should follow something predictable. I'm not sure what though. There might not be any currently selected one. Maybe it can just remember the most recently selected one. If you're editing the .liml file, t…
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Thanks. I'll do a rough survey of literature and see if there's any consistency to this. Do you have a suggestion for an alternative name for this quantity? Perhaps "Tresca stress × 2".
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I can't find any evidence that the term "Tresca stress" means maximum shear stress. I think it's just a sloppy ambiguous shorthand. Neither the page you linked to nor a textbook I have which covers the topic use that term at all. My textbook does de…
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Mecway calculates Tresca stress as the maximum difference between principal stresses without dividing by 2. If you're seeing results that are not that, it could be due to node averaging and lack of mesh refinement. As for whether it should divide b…
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It's just as well it's not obvious because it's wrong :P Sorry about that! You can have a restoring force that depends on displacement in the form of a linear spring. The reason not to use linear is really that displacements and rotations don't upda…
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It requires nonlinear dynamic response analysis. Nonlinear because the restoring force applied by gravity depends on the displacement. Dynamic instead of quasi-static because quasi-static only produces solutions that are in static equilibrium at eve…
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I've reproduced the problem that the ccx.exe 2.15 on dhondt.de can have obvious random errors with modal vibration (*FREQUENCY) that the single-threaded version included with Mecway doesn't. Here is a solution from the multithreaded one on the left …
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Yes, at some stage, I'll look into those earlier reported eigenvalue problems. Just a note that when it says "Using up to 8 cpu(s)", that range does include 1 and it used to be only 1 for the single core version.
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Yes. The CCX from dhondt.de is compiled for multicore but the one with Mecway isn't. I'm surprised it still does that with stiffness and stress though. The multicore versions usually fail more test cases than single core and sometimes produce bad re…
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You mean in the solution? I'll see if I can add that. Can you identify which material properties are most useful besides density?
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It used to be that way (dark/light) but mostly it doesn't matter which side is which so it would usually be an unnecessary detail. I'll probably fix Automesh 3D to allow either.
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There's another limitation of Automesh 3D which I realised isn't mentioned in the error message. Shell elements have to all be oriented the same way (inwards or outwards). The sides of the small shaft are inverted. Use View -> Show element axes t…
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No multi-select, sorry. Only the new menu items. Also delete empty/delete unused/etc. for named selections.
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Not sure if I'm properly understanding this, but it seems like you can already calculate the cold shape and just need modify the hot shape to that without any stress, is that right? For that, you can use non-zero displacement constraints at various…
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That probably makes sense now that default component doesn't have to be there. I'll need to check for possible side effects but I'll add it to my list for next time.
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It's effectively the same as a beta but if no bugs are discovered, I'll make it the final one. One already was (regression to v9 behavior of element selection on wireframe) so I've now updated it to rc2. Once the download page is updated to show ve…
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That's an estimate of the error in the stress that newer CCX versions (2.12-2.15) generate. It's described in the "Gradient error estimator" section of the CCX manual.
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Yes, that's the problem and it's a big limitation of CCX's 2D shell output. The internal solver keeps those 3 values (top, middle, and bottom stress) separate in its 2D element solution so you can view each layer's stress individually whereas CCX av…
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Thanks for sharing the excellent pictures at usual. What will be tied to the loop? Not a wing-walker, I hope!
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The cutting plane slider at the top right of the toolbar does this, but it only cuts along element boundaries so you get a jagged surface. You can also hide individual components by right clicking them under Solution -> Components in the outline…
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Good to hear. Shell offset works for differential thermal expansion with the CCX solver but not internal. I would prefer to use solids for that if possible though. Or at least validate part of it against a solid model if your structure is too comple…
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It should be possible with various ways: * Bonded contact with CCX and the Elastic option * Internal solver with bonded contact * Merge the nodes of the 3 layers and use Shell offset in element properties to position them. * Laminate materi…
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Hello kiran Once you have a contact model, add contact stress through Solution -> New stress and strain -> contact stress then solve it. The contact pressure (negative normal stress) is only shown on the slave surface. If you don't have a c…
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I got it two work in two ways: A ) Changed the fixed support to get rid of the stress singularities at the ends. Might not really be practical for a real structure. (plastic composite v3.liml) B ) Added another stress-strain point to the brittle m…
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I see. Thanks. Though for symmetry, you can use frictionless support instead which is much easier as long as the element surfaces are all in the symmetry plane.
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Could you clarify what's not easy? Finding them in the list or setting the parameters on the big form or something else?
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I can't find a way to do that, sorry. Other than requesting enough modes to exceed zero. You can also do linear buckling with modal vibration (frequency / modal) analysis if you have some idea of the critical load. You adjust the loads until the fr…
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Oh, good find. The demo version has no missing features except being limited to 1000 nodes. It doesn't have any CCX convergence options in the UI but you can enter the CCX card for that (*CONTROLS) in CCX -> custom model definition.
