LS Dyna

LS Dyna

Topics relate to LS-DYNA, Autodyn, Explicit STR and more

Unable solve solution ” solver checks failed”

    • Hayati
      Subscriber

      I have a problem when solving the solution. the message appear after I solve the solution. I already change my end time to smaller values and change the no of points to 200. I also don't know where the log file. 

    • peteroznewman
      Subscriber

      RMB on the Solution branch and Open Solver Files Directory. In the Windows Explorer that opens, find Solve.out and open that with Notepad.  In there you will see the following.


      License acquired!
      Checking model setup.....Please wait
      ERROR! Number of elements exceeded for Academic Teaching version - elements limited to 32000.

      The number of nodes or elements must be < 32000 for the solver to run.  Your mesh has 46,400 elements.


      There are several things wrong with this model.


      1) You should convert this thin-walled solid to a midsurface model using SpaceClaim. Then you will have shell elements with an assigned thickness covering surfaces that represent the car and the pole instead of solid bodies.  Once you mesh with shell elements, you will easily stay below the Student license limit.


      2) You should move the car (or pole) until they are tangent (touching). The reason is that explicit dynamics must use very small time steps dictated by the smallest element in the model.  You have about a 0.14 m gap between the car and the pole.  At the velocity used of 11 m/s, it will take about 0.0125 seconds until impact. That is a lot of cycles to be waiting for the interesting part.


      3) You have correctly assigned an initial velocity to the car.  Don't also assign a velocity boundary condition to the whole car. That turns the car into a rigid body. Similarly, don't apply displacement boundary conditions to the car.  Once it is a surface model, you can pick a circular edge of a wheel well and create a remote displacement to set Y=0. Repeat four times so each wheel is independent.

    • Hayati
      Subscriber

      Okey. Noted. Thank you very much.

    • peteroznewman
      Subscriber

      Please mark this DIscussion as Solved by clicking the Is Solution link.

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