LS Dyna

LS Dyna

Dear ANSYS employees, I recently encountered a strange error

    • spiderman
      Subscriber

      I am performing a display dynamics analysis, and the following error occurred.

      Analyze the general situation: simulate pushing a larger circular buckle into a smaller circular tube. I want to know the deformation and force of the buckle during the entire process of the buckle.

      Now I have encountered such a strange error, and he can no longer work. I feel that this error does not come from "ansys workbench". How should I solve it?

    • Mike Rife
      Ansys Employee
      you are correct - that is coming from the solver Autodyn. Was this a restart analysis? If so the restart file might not be complete. Hence the unexpected end-of-file error. Mike

    • Chris Quan
      Ansys Employee
      By looking at the stress plot, it seems that materials have penetrated into each other.
      Can you check Contact Regions and Body Interactions to make sure all possible contact surfaces/bodies have been scoped?
      Can you check Analysis Settings to make sure Mass Scaling Time Step has a reasonable value if mass scaling is used? You may take a look at the admodel.prt file in the MECH folder to find out how much additional mass has been added into the system. If the added mass exceeds the 5% of the body mass, can you turn off Mass Scaling and then re-run the model to see if the problem persists?
      Finally, check the disk to make sure it has a sufficient space to store the solution results.


    • spiderman
      Subscriber
      Dear cxquan´╝îmrife ÒÇéThank you for replying in your busy schedule
      This is a buckle that consists of a larger buckle and a small buckle, so that it can be stuck in, but it will not come out. What I imagine is that it will go in and spread the surroundings, so I will see some deformation results. But as you said, their models have penetrated each other. I don't know why this happens and how to solve it. I don't know if the error is related to this abnormal situation.
      By the way, I just simulate the entire process of assembly and the deformation. Can I use the transient structure module? I think the efficiency is higher than the EXPLICIT DYNAMICS
    • faceless_man
      Subscriber
      Dearcxquan´╝îmrife. I am a postgraduate.I have a question about the time step size during autodyn analysis.

      I'm doing ananalysis about shaped perforating charge penetrating a steel cylinder ,autodyn belongs toansys17.2 version ´╝îthe explosive and lining are Euler solvers, the outer casing and steel cylinder are

      Lagrangian solvers, the Euler domain mesh size is 0.2*0.2, The mesh size of the Lagrangian part is 0.4*0.4, and the other details are in the attachment.

      There is a question here. As the analysis progresses, the time step becomes very small. How can I improve the computational efficiency?

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