Victor

About

Username
Victor
Joined
Visits
4,653
Last Active
Roles
Administrator

Comments

  • I don't intend to add support for CCX's fluid features except possibly one or two specific bits for a special case. Otherwise it may end up with half-baked fluid capability and perhaps need new kinds of inputs, visualizations, etc. The existing flu…
  • Could you upload the .liml file? The only way I know of that von Mises stress or safety factor can appear negative is the interpolated values between nodes on quadratic elements. In that case, refine the mesh to reduce the error or ignore it if it's…
  • Hello wolland. A couple of problems: The pivot point of the compression only support is not at the end of the beam where the other constraints are. You can see this in the deformed view. That makes it not really a simple support. To correct this, r…
  • Hmm, that error message on maximum shear stress x 2 is a bit odd. But it only works for solid elements.
  • No particular reason, it's just not there. Perhaps nobody asked for it. Though you could create it yourself from the stress in element coordinates components using Solution -> New formula. Interesting idea about using pressure as out-of-plane st…
  • Those mistakes in the build process mentioned above are corrected in the current version of Mecway (13.1). Please don't use the CCX build script or instructions in v13.0 because they're so bad. But there's a new problem. GCC and gfortran were upda…
  • In your example, either value is OK because they're so similar. Anything within the same order of magnitude is basically equivalent. Same goes for radius vs diameter - it doesn't matter. If the materials were really different (eg. rubber gasket on …
  • That looks normal. At each time step, it's solving a new static problem and convergence has to begin again, so the graphs jump back up to high values. Even with quasi-static turned off, there are still time steps quietly happening in CCX so it may s…
  • @MartinB, you don't have to go through a named selection or component. Select the both-sides face selection, change to Select elements mode, then back to Select faces mode. It will be left with only the front faces selected. @prop_design. That new …
  • Yes. Although the initial conditions are quite limited so you may need to accelerate the object from stationary using gravity. Prepare to spend a lot of time on it, especially getting contact to converge. So start with a very coarse mesh and only r…
  • Welcome back Akos Did Z88 stop at the same deflection as CCX? At least that would seem to confirm it's something about the design, not an artifact of the solver. By wrinkling, I meant this kind of effect for membranes in tension. Probably not rele…
  • I see. CCX doesn't have point rotational inertia so I think you'll need to build some structure and position the point masses so they give the required moments of inertia. I would use beam elements to hold them together, though it might be possible …
  • The line pressure load is only for 1D "faces" which are edges of beam and shell elements. You can use pressure or force instead and scale the value by the width or length of the strip respectively.
  • Lower case "d" in FaceId following Python's class naming convention.
  • There isn't a function for thickness yet, sorry. That should come later as part of material properties. Here's an example for surface area of element 1: mw.surface_area(FaceId(1,5)) You could get FaceId using mw.selected_faces() if you've already…
  • Could you attach either the STEP files or the mesh too? For a remote mass with CCX, you can use node-surface coupling and put a mass on the reference node.
  • I think you can do that by adding a Solution -> New formula which produces moment per length about some axis, such as FL.vv * x for the internal force.liml file I attached. Then integrate that in the same way to get total internal moment about …
  • * Create a face selection for the internal faces along the section cut, which has to be aligned with element boundaries. * Solve * Add Solution -> New force and moment -> force per length * Use Solution -> Surface integral to integra…
  • That's a good idea, disla. Yes, it shows the pressure.
  • It looks like you saved it with the CCX input deck mesh only option instead of CCX input deck. It's easy to miss, I know.
  • No simple way. But some workarounds: (A) Save as a .inp file and you can see the node forces listed under the *CLOAD keyword where each line looks like this example: 19,2,90.02083333333 19 is the node number, 2 is the DOF number, and 90.02... is th…
  • The video encoding is usually very slow. Some suggestions: * While it's recording, don't click on anything since that tends to stop the progress display updating, though it shouldn't affect the actual recording. * Set a shorter cycle time which…
  • Though I don't know much about Mohr-Coloumb, it looks like you could use the Solution -> New formula feature in the solution in Mecway to achieve this. If you find the formula for M-C equivalent stress in terms of principal stresses and those two…
  • 1) Yes, those wiggles look like a typical result of time steps or elements being too big. 2) What makes them seem high? Check for mesh convergence. That might go very slowly with linear elements. Quadratic ones are much better on thermal stress pro…
  • Nice clear comparison! The odd stress is because it's averaging the stress for all elements using that node - including the other layer. So yea, you have to use element values like you did. Some warnings only show the first instance they find. I k…
  • All I can think of is to save it as STL and find a tool to convert STL to DXF. Since they're both such popular formats, there must be various options. Here's how to do it with Blender from the top of Google https://www.instructables.com/id/Convert-S…
  • Not really. There must be a reason why it's not the default so I'll just trust Guido or popularity.
    in Solver Tech Comment by Victor April 2020
  • This turned out to be a tricky and serious problem but I'm not sure what to do about it yet. There are two "versions" of CCX 2.16. An older one and a newer one. The differences are: Older version: * Released before 2019-11-30 * Automatically …
  • I see the same problem with the CCX 2.16 included with Mecway but not with CCX 2.16 from dhondt.de, nor CCX 2.15. So this could be a big bug. I'll reply on this thread when I have more progress. Thanks for bringing it up!
  • Regarding the extra MKL DLLs for option 4), you have to copy them from the MKL installation as in option 3).
Avatar

Howdy, Stranger!

It looks like you're new here. If you want to get involved, click one of these buttons!