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Everything posted by boba_fett

  1. I finally managed to get some results for the version with pcont but they don't make any sense neither...
  2. I am trying to simulate an autofrettage process with the optistruct solver but i am not able to get any plausible results. In theory the process and simulation should be quite easy. We have two parts: a swage and a tube. The swage (which has a slightly bigger outer diameter than the tube) is pressed through the tube which results into contact with friction and plastic deformation in the tube. I meshed both the swage and the tube (only one quarter of each and conditions for symmetry to reduce the calculation time), defined all the boundary conditions like constraints and the load (forced displacement of the swage) but somehow the contact condition doesn't work at all. I read several tutorials and have tried different combinations of contact-surfaces or set-entities which were linked by a contact interface. I tried the preset contact types like slide/freeze/stick as well as a contact property with MU1/MU2 coefficients. When I use slide or freeze (images below) I get extremely high deformations and it looks like the points where the first contact occurs don't separate anymore, In addition to that I don't understand how they can already be in contact at that point since the contact should occur later when the bigger diameter hits the edge of the tube. Displacement scale factor is always set to 1.0. When I use the contact property (pcont) the calculation takes forever and I don't get any results (no convergence). I already tried to increase the number of iterations up to 50 and NINC up to 25. I would really appreciate any helpful advice or maybe someone with experience could check my model file. test_12.hm
  3. The results still don't make any sense in my point of view. How is there no friction and stresses at the inner diameter of the tube? And no stresses at the outer bigger diameter of the stempel? And there are no contact forces as well at the outer diameter of the stempel. In reality the stempel should slide through the tube and stress the whole material inside the tube while the bigger outer diameter of the stempel is stressed and deformed during the permanent contact with friction. Nothing of this is happening in the model/results.
  4. @Prakash Pagadala Well... there is some kind of contact now but the results make no sense at all. The geometry as well as the forces and boundary conditions are axially symmetrical but the result is not... and for some reason we only get stresses at the point of contact and not later in the tube as well... I have noticed that you added an additional set "Slave" and two cards and that you furthermore changed the interface from stempel to face... why don't we have the interface between the stempel and the tube? Thanks a lot for your help so far!
  5. @Prakash Pagadala No, it is not. In the middle the diameter of the stempel is 100.40 and the diameter of the tube is 100. So there should be some kind of contact.
  6. Hello @Prakash Pagadala here is my model file test_04.hm
  7. Hello @Prakash Pagadala Thanks a lot, I set 300 for dof2 in both the SPC and SPCD and it worked now. But for some reason the contact analysis doesn't work at all. Usually the stempel has a slightly bigger diameter than the tube which it is moving through. The stempel material is elastic and the tube material is deformable (plastic). I tried both autocontact via the contact browser and following the tutorial for the bolted flange (2 contact surfaces, an interface with master/slave and the set_elem for both properties) but the stempel and tube don't seem to interact in any way. Hyperworks does the calculation and gives no errors, but seems to act like there are no contact surfaces etc. at all. Is it impossible to do a contact analysis with a forced displacement of a part?
  8. Thank you for the quick help @Prakash Pagadala! Somehow I am not able to make it work. I constrained the tube at one surface in all directions so it can't move (using a load collector with SPC type constraints). For the stempel I used a different load collector with an SPCD type. In the final load step I selected the SPC (tube) as SPC and the SPCD (stempel) as load. It always gives me the following error code: "An SPCD component must be constrained by an SPC or SPC1 data." Maybe you have some further advice on that issue. Would be great! Thank you very much so far!
  9. Thank you very much for the quick response @Prakash Pagadala It seems to work so far! :-)
  10. Hello everybody! I am new to hyperworks and trying to simulate an autofrettage process (a stempel which is pushed through a tube). What I need is the final state and plastic deformation after the process. Usually I would create two load collectors for the constraints and loads and then implement a load step (e.g. for a static analysis). How can I define that the stempel is moving/pushed through the tube instead of an acting force as load definition? I am also struggling with finding the proper material card for the plastic deformation. I would really appreciate any help or advice :-) Cheers
  11. Hello guys, I am trying to simulate plastic deformations with Optistruct and I am struggling to find the proper material card image. I have all the data (values for true strain/true stress), young's module, isotropic, solid metal etc. As far as I understand it should be non linear since we have plastic deformations (?), no change of temperature or heat. I really appreciate any help or advice :-) Cheers
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