Jump to content


  • Content Count

  • Joined

  • Last visited

About Chris84

  • Rank

Profile Information

  • Are you University user?
  1. Yeah, that's were I set up the balanced constraints initially. The ply shapes also turned out to be the same. I didn't realy know, what that zone option was for before I looked into it a bit closer just now. I thought MINDIM would do pretty much the same thing. The model I sent you still had the element sets, that the optimization algorythm came up with. However, I edited these sets to get an easier manufacturable version. I just used the default sets for troubleshooting. Just tried it out with the zone grouping option and I got the same result as before. That doesn't seem to help. I'll try the DGLOBAL option again, too. I was sure I had enabled the smear option. Not sure what went wrong there.
  2. Hm, that doesn't sound good. 0.25 mm is, what we have available. I could only change it around by small margins and hope, the actual difference for the real part is pretty minimal. Do you get your non-discreteness by assigning different thickness values to the different plies of one specific orientation? Cause that's the only possibility I see. There're two balanced ply pairs (+/-45 and +/- 15) in there. I also used the SMEAR option in both the free-size and the size optimization.
  3. I wanted to avoid making it accessible for everyone. There's no confidentiality on it, but there's competition (this is for the Formula Student). So I guess deleting it in a few hours has to be enough
  4. Right. Found that in the .out file now that you pointed it out. Did that and it found one other design, which is still violating the max displacement constraint. 11 of the 12 total starting points led to the same result I had already gotten many times before. I've attached the .out file again. Is there a way to send you the model file directly? The forum won't let me send a pm. It says "You are only allowed to send 0 messages per day. Please try again later." in a pop up window after I click on the message button. minmass.out
  5. I hope I undestand you correctly. What I just tried is adjusting some of the layers initial thicknesses to get the overall weight a good bit over what should come out as a result, because I wasn't sure, if the solver will try to stay below the starting value, if my objective is to minimize the weight. The first iteration shows me the weight, that I also got from the mass calc. Also the deformation (my constraint) has obviously gotten lower, so that seems to work just fine. However, in the optimization summary it still states, that there is a constraint violation of 64 % Also with the second iteration all of the optimizable layers get ignored or set to 0 and the design (and the optimization) fails. I also attached my current .out minmass.out
  6. Yes, they are how I get the minimum thickness. Two layers of 0.125 mm, so 0.25 in total The free-size optimization also ran without a problem. The size optimization causes trouble
  7. I don't think there's anything special. By lowering the DELSIZ option to 0.025 in the opticontrols I was able to get the program to calculate a few more variations, but it seems like a pretty arbitrary value. With that set to 0.05 or 0.01 it fails again after the 3rd attempt (which is apparently exactly the same as the 2nd) Tried it with the initial values all set to their max, same result. Any other opticontrols I might wanna change? Also does the Move limit in the size/shape desvar help me in some way?
  8. Hi everyone, I'm having trouble with a size optimization of a component I designed. The objective is to minimize the mass of the part while constraining the deformation at a single node to max 2 mm (+ and -). The result of the free-size optimization gave me a deformation of 1.6 mm and the size optimization always fails with an infeasible design. The program seems to delete all of the plies leaving it with only two, which are predefined by a constant constraint in the free-size design variable. I tested it with the ply sets altered for manufacturing and also tried it with the base sets, which I got from the free-size optimization. Neither works. Both fail after the 3rd iteration with the 2nd and 3rd one being seemingly the same. I have attached one of the .out-files. minmass_base_model.out
  9. Found my really stupid mistake. Seems like the thickness defined in the CONST constraint doesn't overwrite the one set to the ply in the first place. Mine was set to the wrong value all the time ....
  10. I'm trying to set up a free-size optimisation with a fixed thickness for two layers. They're basically the cover of the part and it's a woven fabric modeled with two unidirectional plies, which are constant. The thickness of each half is 0.125, exactly half of all the other plies. I've already tried it with a PLYMAN constraint set BYPLY with a PMMAN value set for each ply with a constant option for the thinner plies. I've also tried the PLYMAN constraint set for ALL with a PMDIS value of 0.25, PMOPT BYPLY (What does this option even do?) and the PMEXC option set to CONST. My goal was to get a fixed thickness value for all of the plies, which I also got, but the plies I set to 0.125 mm didn't keep theirs. What am I doing wrong?
  11. I did some trial and error and got what I was hoping for in the end. Thanks for your help! Also found a good (German) Youtube tutorial by Manuel Ramsaier, that also used a 2D mesh
  12. That definetely worked for the static analysis, but I'm still not sure about the topology optimization. I'll keep trying and report back, if I don't get that to work
  13. Thanks, tried that discrete value, but I was hoping to also reduce the computational effort with only 1 or 0 for the thickness I tried to figure out using the OSSmooth panel for my surface model optimization, but the iges or step file I get as a result only gives me the surface I started out with. I can't use that in CAD
  14. I'd like to create a displacement response (also an optimisation constraint), which is measured at a point outside of my geometry. I tried to fix him to my geometry with an RBE2 element, but that made the RBE2 stretch and the point stayed where it was. I'd like the point to move by the same amount a / some nodes of my component move after applying a force. How can I achieve that?
  • Create New...