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Victor
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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 …
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It didn't finish solving in either 24 or 25 for me. It's possible you have a different version or build of CCX used by 24. 25 would have defaulted to the built-in one when it was installed.
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That's probably the contact state file (.cel) which can be huge and slow to load. To prevent it being created, before solving, have only the field variables you want in the solution, and not contact state. If there's nothing there, Mecway automatic…
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What I did: * Changed the tension force from nodes to faces to make it uniform. * Adjusted the X position of one side of the film's nodes so the elements are square, not parallelogram. This might not have been needed. * Ramped the tension for…
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That's usually what causes it, but in this case, it's an unused node (876). Nodes without elements don't go through to the solution in CCX so delete it before solving.
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CCX sometimes fails such large rotations at specific angles. You can work around it by altering the time step from 2 s to say 2.1 s and it seems to avoid whatever problem it got stuck on.
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You can't have a time-dependent displacement on the same node as the time-dependent rotation. That's a limitation of Mecway. You also can't have constraints on the surface of node-surface coupling, which is a limitation of CCX. A workaround is to e…
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You can use Node-surface coupling for that.
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You're right, it doesn't have sufficient constraints. Beware that the pinned support only pins one point even if you apply it to two nodes. If you want two pinned supports, either use two of them or 3 displacement constraints on two nodes. There's…
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If you're using large displacements, the line of action for the force from each screw might change as it bends, otherwise, for linear analysis, I think using the hole would be fine since you're interested in the behavior away from the hole. The sup…
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I see. This isn't really consistent with an original design decision to keep node numbers hidden as much as possible and only using consecutive numbers. While it's possible, the ordering would be messed up if you delete something from the middle and…
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I don't quite understand. But I'm trying not to have node numbers exposed as much as possible. You can change the node numbering of an element in Mesh tools -> Element properties, and there's Mesh tools -> Invert to swap to one other ordering…
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It also works if you apply the force to the elements instead of their faces. I think the reason is that on faces, Mecway generates tiny moments due to numerical error and these might be what's breaking CCX.
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It's supposed to work. This looks like a bug in CCX. It solves with CCX 2.16 but not 2.17-2.21 which have: *ERROR in add_sm_st: coefficient should be 0 It solves OK with quadratic elements so maybe you can use that instead? Generally a good idea a…
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Thanks @disla for that very comprehensive exploration of ADJUST. Especially ADJUST=NO. I didn't know interference fit won't work without that! If I make this an input, would you say there's any value in allowing arbitrary distances or just ADJUST= …
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@disla Good point. ADJUST is supposed to happen automatically for penetrating nodes which might explain why @JohnM's solution works. Somehow I thought it was already using ADJUST in all cases. When it's not, are the contact springs initially under …
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CCX has viscoplasticity but it's not in the Mecway GUI. You can probably use it by writing some cards by hand. See *VISCO and *CREEP in the CCX manual. CCX also has other non-viscous material models. See *HYPERELASTIC and *HYPERFOAM.
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I see. I've added it to my list but not sure when I'll get to it.
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Not particular reason. It just didn't seem important at the time.
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You're right, line pressure doesn't include the bending moments so you have to refine the mesh for them to appear due to the forces on nodes along the span. The same is true for pressure on shells. Would you say this is an important omission?
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This is bug that happens when there is: - Contact that doesn't close anywhere and - contact state field variable in the solution, or nothing in the solution so it automatically includes that. A workaround is to add all the field variables you want …
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Good points @German and @prop_design. Sometimes I copy requests onto Github myself. That's an embarrassing mistake with the more info label!
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The critical load is buckling factor times applied force. You can adjust the mesh according to the mode shape and a scaling factor using Mesh tools -> Transfer displacements from solution.
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* Set analysis type to Bucking 3D * Choose a Number of modes. I normally use 3 or 4 to get a sense of what else is around even though only the first mode would actually occur. * Set Shift point to something less than the lowest buckling factor.…
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Hello Nigel Case 1) You don't need tension-only if you know it will always be in tension. In either case, truss elements won't work because the pulling point is unconstrained in the direction of the applied force so no linear static solution is pos…
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The circles represent pin-joints which truss elements have at both ends, so they're free to flop all over the place. Usually, you shouldn't refine truss elements for this reason. If you really need to - eg, to capture bending of the members due to l…
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I prefer if feature requests go in Github https://github.com/victorkemp/Mecway/issues so they don't get lost and other people can upvote them (thumbs up reaction).
