Hi,
I'm having trouble with an odd error with my rigid wall force output.
In my first set of sims, I was crushing a tube structure between two rigid walls. One wall is fixed, the other has an applied displacement. When looking at the d3plot in PP, I was able to get "Rigid Wall Force, wall#2" (the moving wall) loaded from the Global History button to have some non-zero value but I found it odd that "Rigid Wall Force, wall#1" (the stationary wall) was always zero. That didn't make sense to me as far as equilibrium was concerned but since I was able to get the force from at least one wall (and it agreed with my experimental values), I was ok.
Now I'm trying to solve a very similar problem but now there is only one rigid wall with the other end of the tube with a simple fixed node condition against all DOF. If I apply the displacement to the rigid wall, the simulation runs as normal but when I try to extract the "Rigid Wall Force, wall#1", the value is always 0.
I have the RWFORC flagged under the ASCII_option although it never writes it and I cannot load it from the ascii button. It shows that there is no file for rwforc. I'm using parallel computing on supercomputers so I'm running with multiple cores and a colleague suggested that I must write to a binary file as well as the ASCII file. If I do so, the binary output file crashes LS-Dyna every time I try to load it.
Any suggestions?
Thanks,
J. Haley
That is strange. So disclaimer, I never use *Rigidwall but I just make a 2D mesh and assign material *Mat_rigid. If we cannot get the issue resolved then I would suggest trying that and extracting the force from the RCFORC. At least you will be able to get some results.
The one thing that I can think of regarding why you are not getting a force from only 1 wall is that maybe it's direction is backward? As in something similar to a normal direction? I'm not familiar with rigid walls but I know that normal directions can cause issues with meshes and retrieving force in other ways.
And is there a slave and master side for the force output when you load the RWFORC? Sometimes one will plot but the other won't.
That’s the odd part, I can’t extract the rwforc nor the rcforc, it will not write the ascii file (presumably because parallel computing). Otherwise I’d just get the nodal force from the bottom of the tube or use a discretely meshed part.
I had the same thought about the wall being “backwards” and turned the wall around but that also didn’t fix it.
In the *Database_ascii RWFORC make sure that you have a reasonable DT defined and try changing all of the outputs to Binary option 3. This will write out a binout file which you can load in Post -> Binout. See if that fixes it.
I've done that. There is a binout file that is written. Importing it into PP causes it to crash every time. The dt is set up to record 200 stages, which is easily handled many, many times before. Am I importing it incorrectly? I've tried loading it from the ASCII graph tab and also from file>open.
I have the most recent PP and running dyna-11.
File > open > binout
or under the ascii button, load > binout.
In your folder where the binout file is, are there more than one binout file? You should load the binout0000 one or something similar to that
If you feel comfortable doing so, you can email me a zipped folder of the sim .k files and the output files so I can take a look at what’s going on.
contact@feassistant.com
Sure thing, I'll actually have to upload them to a drive. They're pretty massive files.
Well, if they are that big try only including the acii and binout files from the output. D3plots would take up the most space
I was able to load the binout0000 and got plotted the rwforc. Attached an image of the force. Maybe you were trying to open one of the other two binouts (binout0000%001,binout0000%002)?
That’s exactly it. But I was trying to open the binout, it just crashes. How are you opening it?
Ah I just went back to your previous post on how you were opening it and that’s not the way I do it.
Don’t open it through the File toolbar. Just go straight to the Post toolbar on the right then Binout and Load and find the binout file in the browser.
Also if you ever open a d3plot, the folder will automatically be the one where the d3plots are when you go to load a binout. Just a tip.