Fatmac

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Fatmac
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  • There are several possible approaches, one is with beams and some sort of connection or another beam as u outline in ur question, then there is the option of beams connected by a shell or even a solid. The 3d shape and sort of loading may make one s…
  • thanks again for the heads up - sounds like i will cross them off my list of elements to use
    in S4R elements Comment by Fatmac April 24
  • Disla - Thank you for the answer. My knowledge is so limited I had to look up what MODE 111 meant - if my source was correct then Mode I = opening Mode II = in‑plane shear Mode III = out‑of‑plane shear / tearing the fact that the calculix S4 el…
    in S4R elements Comment by Fatmac April 24
  • here is a picture of the set up, the papers results and the S4 element results
    in S4R elements Comment by Fatmac April 22
  • select node (or surface), right click on the point, select displacement, chose which axis you wish to restrain, and then enter zero at the bottom to fix it
  • that was it - i had pointed to a version i downloaded from the mystan website -mystran-17.0.0-windows-x86_64.exe, it ran but only the displacements were displayed, now i have gone back to the version shipped with MW33 all is good -thank you
  • i expect it will be something stupid i 4got to do!
  • no stress or strain output for the mystran test
  • one approach is a sort of hybrid cad import/mecway build. I would look at importing a few faces or sections form the .step file then extruding and manipulation with in Mecway. If u are able to drop the solid model here I can suggest a work flow that…
  • he is the force Sum based on the displacement nodes
  • nice demonstration of displacement vs force pretension. I could not help but take a closer look at your model (I always like to see how others approach these type or problems). Interestingly, I think this could be another example of a model that po…
  • Sergio -I am very interested in ur 2nd example. I have played around with this type of model and have come up with some observations I would like to share and get comments on. -I think you have all the contacts in the 2nd example as unilateral (whi…
  • Yea auto time step certainly helps convergence. The bit that surprised me was the very differing solution with the same solver but different version- see pics in last posting
  • I have attached the file and some pictures. In the end i got myself a little confused - in one case i appear to have got different solutions with the same solver but one using the keywords and one using the default which suggested it was using the s…
  • Always nice to have a new update. I was wondering about the reasoning behind the default hex element being C3D8I, is there a feeling that C3D8 and/or C3D8R are not reliable? Also it appears the default quadratic hex element is C3D20 - not C3D20I, …
    in Mecway 33 Comment by Fatmac March 22
  • I realise there are many situations where shell elements are the best solution but I avoid them where possible - in Calculix I regularly run into issues with shell elements (they are expanded to solids during the analysis anyway). If u continue usin…
  • In most cases it will be best to modify the model in the CAD and export it. However Mecway makes manipulating the mesh very straight forward - sometimes it is much easier to fiddle with the mesh to make small changes to the model. There are several …
  • I had a quick look and wondered if there was some interference with the parts, when i ran it the original model with no load or pretension there appeared to be some residual stress produced. Also looking at the mesh in cad -this indicated there may…
  • This issue has confused me a lot in the past - now my work flow for any contact analysis includes an initial run with no loads applied to see if there are any odd interferences. In this case I see the interference here. The odd part of it is that wh…
    in CXX Contact Comment by Fatmac March 6
  • I download both ur .liml and step file. I struggled to make a decent mesh form the step file with in the .liml. However once I downloaded the step (which came out as a polysurface with no sides in rhino) i generated a full solid - brought it back i…
  • I had a look at this using solid pop rivets - i introduced a bit of pretension in the rivets by cooling them. The overall deformations look sensible. However, a quick look at the stress in the rivets made me a little suspicious of the results -thi…
  • I have been playing around with contact analysis of late so had a look at this analysis. I have seen some situations where the same analysis run in quasi nonlinear with a nice steady time based displacement have trouble converging where as if i just…
  • if u wish to connect the parts by just the rivets then bond using the surfaces where the rivets connect to - see pics
  • assign the material to the parts then bond them together
  • I've had a few days working with V31, up to now I have seen no issues. However this afternoon I had the program crash. I got this error Error. Please save your work in a different file, close Mecway and report this to support@mecway.com The given k…
    in Mecway 31 Comment by Fatmac January 14
  • Have u tried merging nodes?? keep the surfaces as different compounds so u can have them as different materials but use merge nodes to tie them together - if they are not exactly coincident then try slow increasing the merge tolerance till they mer…
  • I noticed the opposite normals in the original model and was not sure how to correct them - can u let me know the trick. I am interested in the run time with out the quasistatic option -it solves much faster. I imagined (wrongly it would appear!) th…
  • I had a quick look at your project. My first thought was that using node/surface couplings with shells in a NL analysis always ends in tears for me - I normally revert to using solids (especially where the plate is this thick). Next thought was I ha…
  • Thank you for getting back on this -and yes I did miss attaching the simple file, I've tired to this time. What I was hoping is that I could use the ID generated in the input file are redefine it in some sort of custom model definition input. In th…
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