3D Design

3D Design

jagged shapes in force vs displacement plot

    • emoshe
      Subscriber

      I am new to ANSYS. I am working on a nonlinear thermal buckling simulation with the boundary conditions as being fixed at both ends. The environment temperature is set for 22 C and the thermal condition is set to 500 C. I am using mapped face meshing as well as body sizing to create my mesh. I do not understand why and how I am getting some jagged shapes as the plot curves out and eventually starts to flatten. I have attached a MATLAB plot that displays force vs displacement labeled as snip.png. The dotted lines are indicated the mechanical critical buckling loads. The mechanical curve, which I have not included, is a smooth and flat curve; I was expecting something similar with the thermal loading. I have also included snips of the analysis settings , the thermal condition, and the perturbation used. Any help will be appreciated.

    • 1shan
      Ansys Employee
      ANSYS staff are not permitted to download attachments. Please insert inline images to support your query. Also what doe you mean by "jagged shapes"? Are you talking about the deformation or the smoothness of load deflection curve?
      Regards Ishan.
    • emoshe
      Subscriber
      Jagged as in the load deflection curve.
    • peteroznewman
      Subscriber
      Under Analysis Settings, with Auto Time Stepping ON, set the Minimum Substeps to 200 or more to get more points along the curve and see if that smooths out the curve.
    • emoshe
      Subscriber
      Only change I made was switching it to substeps and typing in 200 as the minimum number of substeps.
    • peteroznewman
      Subscriber
      I suggest you add a zero and request a minimum number of substeps as 2000. If that makes for a long solution and you are more interested in smoothing the curve in the first 10 seconds and not the last 30 seconds, then change it to a 2 step solution. Step 1 has an end time of 10 s and step 2 has an end time of 40 s. That way, you can request a minimum of 1000 substeps in step 1 and only get 100 substeps in step 2.
Viewing 5 reply threads
  • You must be logged in to reply to this topic.