@Sergio, introducing mesh imperfections can indeed be a way to obtain a more physically accurate result because reality isn't ever as perfectly straight as an FEM model can be. Years ago, i read an article on modeling failure of aluminum honeycomb c…
@disla, My reasoning for seeing if I could force necking to occur in the center was that my first thought was that the accumulation of small numerical errors would be the only reason for seeing any necking at all in a uniformly loaded specimen. The …
The oddity got worse. Expanding the kink in the center to be a wider band that is 5,01% smaller cross-sectional area (as the picture below) still didn't result in necking in the center.
Removing elements in the center did force the necking to occu…
I've looked a bit more into it and I'm becoming increasingly sceptical that the necking is the simple accumulation of numerical error in what is ideally a uniformly stressed specimen. With cubes with a sidelength of 8 elements and a timestep of 0,00…
With the refined mesh and the small timestep, both behave similarly with necking initiating from around 1mm displacement (1st principal strain around 1,3) but they end up with slightly dissimilar levels of plastic strain in the necking. I don't trus…
I noticed that the timestep was so great that the first timestep was beyond the linearly elastic region, which I thought might be the issue. Reducing the initial timestep didn't change much but reducing the maximum timestep as well to 0,0005 seconds…
Awesome
Congratulations on the new release.
I'm especially excited for the compression only support being usable CCX as it makes sense to be used for pinned boundary connections when the stresses near the pinned hole aren't completely irrelevant…
I can't tell what's wrong. I'm running the python scripts with Spyder through Anaconda Navigator while it seems that you're running in IDLE which I cannot as it simply states that numpy is missing.
In spyder however, it seems that the next step aft…
I'm still working on this with Mecway as a preprocessor. I've altered the BESO code so that the initial state can be set based on the components in Mecway, so I can make an initial seed or guess in that way.
This however exposes the need for more r…
Sergio, it could be possible but as I have no experience in running user scripts in Mecway and this is also my first serious encounter with Python, I have not yet attempted to do so. If anyone else has the courage to try, then it'd be cool.
I found a setting in the beso_config.py script that exports the solver .inp instead of just the mesh. Thus, the loads, displacements and materials are imported and ready to run. The loads and boundary conditions are however applied to the nodes indi…
In the result files, they do not include *ELSETs or *SURFACEs but the node and element numbers appear to be the same as in the original .inp file. Edit: the beso script can be made to export nodal loads and constraints. More details in the next comm…
Hi there
Just an update: It works. I set up an analysis in Mecway to be run with Calculix, run the analysis, click "details", then the .inp file button which opens a .txt file which I then save as .inp. Then in the beso python script, which I open w…
Interesting, I'll have to give it a go. Drawing the 3D model will be easy as I'm using Solidworks for all of my CAD work now and are used to exporting STEP files to analyze in Mecway.
Nice to hear that it works.
Could you clarify what you mean by running it directly on Calculix?
I have only ever used Calculix with FreeCAD or Mecway as a user interface and are interested in if this could enable topology optimization using Mecway.
Great to have a .bat file posted. By reading how other people use them to automate tasks it seems to be something I need but I just never knew what a .bat file should be like.
It would be a time saver to be able to automatically generate pairs of named selections for pairs of faces on different parts that was closer than some specified tolerance. It would make it so much faster to apply contacts after having imported a bu…
I just had something similar with simulating a rubber/steel bushing used in automotive suspension.
When position tolerance for tie was set to 0, there would be parts which was not connected but when the position tolerance was set to 1mm, then it bo…
So now I got a new workstation and Damn it is fast!
CPU: AMD Ryzen 9 5900X 12-core processor 3,7 GHz.
RAM: 64 GB
Mecway 15, calculix 2.19, ccx_static.exe. Running PaStiX. The same environment variables as my comment above.
Runtime with 1 CPU co…
@Sergio I did export some surfaces at the faces because they only bent one way and some surfaces at the mid-plane because they bent both ways or had contacts from both sides and I thought that that would make it easier to make the contacts as the su…
What I'd really like is a continuum shell element like ANSYS has SOLSH190, ABAQUS has SC8R or possibly the "layerwise kinematic method" by J. N. Reddy. It would really be cool for sheet metal or composites analysis but with the difficulties of shell…
@disla
7. These factors are not 1 since they are what is describing the relationship between the stresses and the force, width and module so in some sense they are describing the (assumptions of) geometry and the load direction. It is how the stres…
@disla No problems, I'm happy to discuss with peers.
Sorry if I'm dragging it too far away from the main subject of constraining movement but I just got excited when I saw a post on the subject of modeling gears.
1. Maximum bending stress and max…
I'm also analyzing gears but a bit differently than what you have shown since I'm doing it for designing purposes and are doing it at only two orientations per pair.
I'm doing it in 3D because my gears are not completely uniform in cross-section, s…
@protontim I've also had issues with meshing gears exported as step files from solidworks where the solution was to check "split periodic faces". I haven't figured out what caused the issue as some gears had issues while others hadn't even though th…
@Victor The "relative to previous" option when placing individual nodes by coordinates has dissappeared in the beta 3 version of mecway 15.
Is this intentional or a bug?
@Victor, Fine about the solver, I'll just copy files like I did with version 14.
If distributed node-surface coupling gives the wrong results, then of course we shouldn't use that but it's just nicer to not have to calculate the magnitude of the m…
Congratulations on the new release.
Could you elaborate a bit on the "CCX updated to 2.19 with source code that includes all required MKL files" part?
It is still the Spooles solver that's inkluded as far as I can tell, as it is what runs when I r…