JohnM

About

Username
JohnM
Joined
Visits
2,355
Last Active
Roles
Member

Comments

  • The pyramids are occasionally cursed. I have had problems with this using the local refine, mostly on structural stuff. With this being a thermal and only 1DOF/node, can you get away with refining the whole model?
  • Victor can say for sure but I think this is just a viewing problem. Occasionally see a difference between what I I see in the viewing CAD versus what actually comes out when I mesh. Go back to your original source code to be sure that everything's …
  • I've attached something similar, take a look. Couple questions - is the 5kN target a radial clamping force for torque resistance or something else? - what are the clamp and clamped part materials? Interesting problem, definitely a good use of Mecw…
  • This issue is present in many FEA codes. Try to disconnect the nodes and use bonded contact.
  • See my comment above in this post from 2019. If you learn to use these *include command in CCX custom input, you can open up a lot of flexibility in your loadcases. True, this is a workaround, but it works well and you can use this right now.
  • I found it interesting to replace the force with the equivalent Y-displacement (I used 0.157399*t based on your result). It is an interesting problem - the knee in the load-deflection curve does not appear until all three spars have yielded
  • I posted this on LinkedIn, got over 30k views. I think you are onto something Victor... https://www.linkedin.com/posts/johnmannisto_openradioss-mecway-activity-7238656023182413824-O-6e?utm_source=share&utm_medium=member_desktop
  • Very nice
  • Two ways that we typically loop through mcway databases with variables we like to change: If there's a way to turn the command into a CCX custom input, you can make it a *include to manipulate an external text file. If you have python chop…
  • We have used Mecway to prepare OpenFoam models for many years, similar to how it's shown in this video. You basically need a program to convert your Mecway model to individual STL files for each patch, then a script to pick an approriate template. …
  • Named selections are useful for post processing. For example, pull down the solution tab and try to Sum, you'll often get a big list of "Selected Nodes(5)" kind of stuff. But if you've named something fixed_plate_surf, there it is for you to sum yo…
  • I used ANSYS in the "old days", stored models on 9-track tapes (young people go look this up). I knew developers by their first name, and could call them directly. John Swanson visited our office to see how we were using his product. He was great. …
  • For thin gaps try air conduction - try extruding normal off surface and then project new nodes onto the mating surface For larger trapped air volumes, use the forced convection feature - create an internal node, select internal surface for convec…
  • Mecway- https://youtube.com/shorts/W6l1npfaYto?si=YpzsQC5Q1OaIsMgW
    in Pendulum Comment by JohnM August 2024
  • if you have a lot of loads manipulate, this might be a time to open up notepad2 and find a way to do a change all to add the *t. can't hurt to try, just make a copy of that thing!
  • Make sure you are considering the flywheel inertia in the system, if you are actually going to run a full dynamic you will need this for sure. You will find that at normal operating conditions, the inertia effects dominate the system. Also, the pis…
  • I did this work for 20 years, there are many ways to approach this problem depending on the fidelity and design goals - an ambitious starter project! For a general approach if the goal is a fatigue assessment, you will want a good looking mesh that…
  • I tried running without plastic properties, still does not complete. I would check your set up with a linear run before you add plasticity. Also, bilinear curves are usually 1/10th the elastic modulus in the plastic region ~ 21MPa for your steel. Y…
  • By cutting the model in half and holding the cut surface in the X-direction (I think that was the direction), you essentially get a "mirror image" result. It cuts down on model size. Modeling your thin film with a single linear hex8 through the thi…
  • Fun problem. I increased the density, used symmetry, changed where the roll starts. I had trouble wrapping the wrap as it came full circle, I think this would take some clever time stepping.
  • Since Mecway liml files are in xml format, there is a powerful Python import that opens up a lot of possiblilities: import xml.etree.ElementTree as ET I am not a Python programmer, but the guys here who are use this import (along with other typica…
  • Lucky you, someone looking at the forum on a Sunday morning Memorial Day weekend :-). I am familiar with your frustrations. The initial contact step was added several revisions ago because the contact condition developed "over the first load st…
  • Use the Pastix solver, available pre-compiled on the Calculix website ( the "files" link). Link to the ccx_dynamic.exe executable. You can use the CCX solver switch to change to Pardiso if necessary.
  • Solidworks is not any better at retaining face numbering. We can reload CAD and maintain surfaces for things like tolerance studies, but as you say, remove a fillet and it's square one. Possible cheats: If you are re-working one part, try and set …
  • I think I've posted this before, but couldn't find it, so here it is (again I think): Think small - small models, small time steps. Model sizes can grow after things start making sense. Very stiff models are hard to run/converge. Run a modal anal…
  • FYI, here is what I am currently do that works but is a pain to implement: -I set the modulus of the component of interest very high and re-run. -I dump displacements for the "real" and "stiff" cases. -I take the difference between these cases and …
  • FYI, here is what I am currently do that works but is a pain to implement: -I set the modulus of the component of interest very high and re-run. -I dump displacements for the "real" and "stiff" cases. -I take the difference between these cases and …
  • Thanks for looking at this @fatmac!
  • Thanks for looking at this @disla!
Default Avatar

Howdy, Stranger!

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