Eng-Tips is the largest engineering community on the Internet

Intelligent Work Forums for Engineering Professionals

  • Congratulations waross on being selected by the Tek-Tips community for having the most helpful posts in the forums last week. Way to Go!

Search results for query: *

  1. ahildershavn

    Excessive Pivot ratios in shell mesh

    Thank you. I was unaware that I had created two 2D-mesh frames. Attached here is the geometry I really wanted to simulate. Also, I have now managed to solve it using Erik Panos tips for PSHELL1. I only have few question left then, what happens in PSHELL1 when Material 4 is left blank? And...
  2. ahildershavn

    Excessive Pivot ratios in shell mesh

    Yes, sounds like that could be the problem (disconnected mesh/duplicate nodes), but it is strange that with all the different ways of creating cad or importing cad and using stitch there is still a problem I cannot fint. If you can spot the issue, I would be very...
  3. ahildershavn

    Excessive Pivot ratios in shell mesh

    Well, I have tried sol 103, I have tried adding a variety of different constraints, I have tried different element types. I have tried BAILOUT -1, INREL etc. etc. To me it seems like a bug in the solver/software. Seems like some elements have no stiffness at all, but I have checked material...
  4. ahildershavn

    Excessive Pivot ratios in shell mesh

    Hello, I have this simulation attached. It is a frame and it is shell meshed. However I am struggling to run a simulation on it because I always get an excessive pivot ratios error. I have tried running Bailout -1 but to no help. Could not figure out where the error is. Can anyone help me...
  5. ahildershavn

    Abaqus: Explicit or Implicit for forming processes?

    Hello, I am currently involved in simulation of bending of aluminium sections. So far most of my simulations have been performed using Explicit solver as this is supposedly faster, however when using Implicit solver the results seem to be better, with less trouble with excessive...
  6. ahildershavn

    Restart analysis

    Hello, I am going to restart analysis, I have added some local coordinate systems in the newly created step, but now I get the error message when trying to write the job: "Since the current model is being used for restart analysis, the CSYS transforms for the following newly created attributes...
  7. ahildershavn

    Distortion of elements

    Hello, I have a three point roll bending process where I am struggling with high distortion of some elements. The workpiece is moving from left to right in the image below. THe friction factor is 0 and the rollers are all discrete rigid. Does anyone have any suggestions on how to solve this...
  8. ahildershavn

    Killing Abaqus job, can .odb file be opened and read?

    I am currently running a dynamic explicit job in Abaqus, but the process seems to take longer than expected. I am considering killing the job, but I won't do that if I loose all progress. Is there a way to kill the job, but at the same time ask abaqus to write results up until that point? Can I...
  9. ahildershavn

    Restart/continuation with changes in boundary conditions

    I do want to go for a restart/continuation. But the manual does not give details on the practical bits. 1.) Do I run the simulation then make the changes on the same Model? So in my case, do I just make the necessary changes to "Model-1-exp-13mm" and suppress old loads and add new ones? 2.)...
  10. ahildershavn

    Restart/continuation with changes in boundary conditions

    Hello, I have a three point roller bending process for an aluminium profile. I decided to split the process into two simulations. The first simulation is to lower the top center roller down onto the workpiece to get an initial bending. This simulation(Model-1-exp-13mm), a dynamic explicit...
  11. ahildershavn

    Implicit versus Explicit FEA in parallel computing

    So if I understand correctly: 1.) Implicit requires inversion of the stiffness matrix [K]. Implicit requires solving system of variables with more than two unknowns. Which is why the task cannot easily be split up and sent to different nodes/cpu cores. 2.) Explicit requires inversion of the...
  12. ahildershavn

    Abaqus and parallel computing

    I was told by my supplier of Abaqus software that Abaqus will benefit from parallel computing up to 64 cpu cores. More than 64 cores show little benefit in computing time and beyond 128 cpu cores total computing time actually increases. I am uncertain as to what type of simulations my supplier...
  13. ahildershavn

    Implicit versus Explicit FEA in parallel computing

    Hello, I was wondering if anyone here could explain to me in a simple manner why implicit fea benefits less from parallel computing than explicit fea? Hopefully awaiting intelligently elaborated replies easily understandable by a person whos mothertongue is not english. -Andreas-
  14. ahildershavn

    ABAQUS FEA of aluminium profile bending: Which mesh type would be most ideal for this?

    The mesh shown is just a coarse mesh I made to check if the simulation would run. I have divided the profile/body into regions and added mesh seeds on relevant edges. I will post an update as soon as I have made the changes. Thank you for advice. -Andreas-
  15. ahildershavn

    ABAQUS FEA of aluminium profile bending: Which mesh type would be most ideal for this?

    Hello, I have just started using ABAQUS for the purpose of simulating the bending process of an aluminium profile. See attached image for typical profile section. The bend radius is not severe, but defects(bulging etc. ) do occur in practical experiments. As I am used to a program called DEFORM...
Back
Top