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JohnM
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A trick I have used for a quick "press fit" check is to apply a frictionless boundary condition on the radial surface, but use an actual value to displace/crush. This works well, especially if the parent material is relatively stiff. I will al…
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Nice work Ken! I've had to do similar things for simulating the stiffness of fin packs in heat exchangers. It's why it's worth understanding how this stuff actually works :-) Young engineers today can't imagine that you started your model one line…
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Use the Mesh->Hollow command. If you need to keep the original model, just make a copy of it first.
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Attached below is get_some_stresses.py , a nice script written by @CornelisP that outputs 6 component stresses to a text file for further postprocessing. Also attached is text_format_solution.liml, which is a sample model with post results written i…
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Boom! Double slash did it for me.
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@Hengre, there is a post with a few API that have been shared. https://mecway.com/forum/discussion/comment/5109 I'm particularly interested in leveraging this functionality, if you work out how to call your Fortran, please consider sharing! That wo…
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Smooth is handy with manual meshing- keep!
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@disla there are times the "red" can be ignored. You will get that same warning if you use self-contact in a nonlinear static run (master/slave surfaces the same). But it works!
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sample dynamic with contact
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We use dynamics with contact. Works fine. Keep contact stiffness values reasonable, set time step small, be smart about mesh size!
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@kennethfugate Try creating your plate mesh with OD that equals the inside of your bushing. Extrude this face in the axis direction by the length of the bushing, then extrude the radial surface outward normal by the thickness of your bushing. Right…
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The method you describe will select all faces in the currently selected model. If that's what you are looking to do, then yes, that is the easiest. But if you are trying to select surfaces on one part out of several in the currently selected model, …
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Select all nodes, then click the surface icon in the top of the viewport. This can be useful for creating a complex surface set. For example, if you had a threaded screw, and wanted to select just the threads, you might: - Select all nodes, get th…
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I consider myself a somewhat proficient Calculix user, but I have to confess it too me about 15minutes to figure out WHY this works! Good post, it's going into my tool bag.
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1- You can use many methods, but the simplest is Mecway: Add the pretension and bonded contact, store in your Library, then grab when needed: 4- yes, use Move to displace sections of bolt to stretch to proper length. Keep your library bolt model…
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Some practical suggestions for modeling bolted joints: 1- Create a library of bolt models using hex elements (these make stretching easy). 2- Include bolt pretension and bolt/flange bonded contact, including "empty" flange face. 3- When bolt model …
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Definitely an underrated feature. Try using an image overlaid on a background mesh for model creation:
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From a conversation I had with Victor: "If the number of elements is different in the solution than the model, it does that because Mecway doesn't know how the solution element numbers map to the input element numbers. That happens if there are any…
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That's an interesting request, but I don't think there is a way to do this (yet), and I'm pretty sure the API does not have a "save plot" command. When I have had to do this in the past, I would keep the Calculix FRD file and make a batch script in…
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They will not act the same. Take a look at this: https://www.fidelisfea.com/post/isotropic-kinematic-or-mixed-mode-which-hardening-model-for-your-abaqus-fea-analysis
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A modal analysis will find 6 - 0Hz modes for each DOF in an unrestrained body. If you have N parts, this will be 6*N modes. Normally if you are checking for loosely connected parts in an analysis, there is no need to let go of (delete constraints) …
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By the way, a simple way to find "loosely connected" stuff is to run a modal analysis. Don't delete constraints - simply run a modal with a good number of modes, and disconnected/loosely elements will show themselves as low or zero frequency respon…
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Manuel- You often start with a simple static analysis of a single component and then extend as necessary. It's important to have a problem statement to define what you trying to learn. For example, using a Static Analysis you can simply load the cl…
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Manuel- Congratulations on your interest in FEA, welcome to the career that has kept me fed for almost 40 years. I have a strong opinion about learning FEA. I say "just do it". I get many interns and new graduates that have been subjected to an …
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@Sergio, thanks for yet another great validation of the solver!
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here is an old benchmark that looks similar to yours: https://mecway.com/forum/discussion/750/propeller-hub/p1 I ran the cube with PASTIX 1 proc - 21% CPU usage 1:45 6 proc - 70% CPU usage 0:58 similar with PARDISO
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Ran a few tests: bolted joint with contact, 100k DOF run times ccx_PARDISO.exe from calculix_2.17.1 with 1 processor 11:55 ccx_PARDISO.exe from calculix_2.17.1 with 6 processor 6:58 ccx_PASTIX 2.17 by 3rav 31 aug 2021 with 6 processor …
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Good option, thanks Victor! We looked at the *SECTION PRINT command, which would be handy for this application, but it is very dependent on mesh density to get an answer close to correct. We often have curved surfaces, so the current "trick" is to…
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Here's another one for you consideration. This is a test problem that is very "fragile". In other words, it can crash pretty easily. Some things I know - - Use auto-time stepping with no lower bound but restrict the upper time step (it will pro…
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Pin/ bushing work best with hexahedral geometries when possible. Elements with mid side nodes will also help preserve the curvature characterization. Tetrahedral meshes, especially if not very fine, can give some strange results. Here is anothe…
