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Victor
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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).
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STEP
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The next version (25) will probably have support for Alibre Design/Atom3D assemblies where each part becomes a separate component in Mecway. Not for general STEP files but I hope to find a way to achieve that because assemblies are quite important.
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The problem here is to find wrinkling so the elements need to be small compared to the wavelength of the wrinkles which is a bit unknown. Maybe it's too coarse? The CCX manual has an example of wrinkling due to shear in section 5.16 Wrinkling of a …
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Since displacement isn't proportional to load, you will need nonlinear analysis (Nonlinear static 3D and CCX solver). It probably needs an initial imperfection too, like some nodes moved a little. I couldn't find any wrinkling that way but I wonder…
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Not currently, sorry.
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They are supposed to have the same effect globally, yes.
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Contact stiffness is so low that it looks like they aren't interacting. Units are Pa/m but should probably be GPa/m. You can set the entire surface of the plate as contact face instead of a patch in the middle.
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Yeah, it's the condensed DOFs appearing in multiple equations problem. For example, x displacement on node 61 is the condensed DOF in both these equations: ... Change the order so the 1st node isn't the comm…
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@sofien_73 What you posted looks OK. A likely problem is that the node-dof pair that's the first term in each equation is the condensed DOF and is not allowed to appear in any other equation, nor various other constraints. For more than 2 nodes, th…
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You can use View -> Open cracks which separates coincident nodes. Another thing I sometimes do is Mesh tools -> Merge nearby nodes and check the total node count to see if it went down, then undo. Doesn't show you where they are but does show…
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Yea, it could use a tool to combine them when they're equivalent.
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It's not possible with the same mesh since a single node can only have one value for each variable. You can disconnect the members at the connections, keeping the nodes at the same location and then join the nodes with constraint equations (all 6 D…
