General Mechanical

General Mechanical

Exceeding magnitude limit. Multiple bodies.

    • Falconitexz
      Subscriber

      Hello everyone,

      due to performance im trying to make the meshing of my workpiece become simpler. I tried to make separate mesh  for two different solid bodies combined as one part using shared topology. To the nodes on the surface  i applied some imported force loads. But now when i solve the solution it will come with this error:

      am i supposed to  create some contact between them?

    • bhagwantP
      Ansys Employee

      Seems it's not reading inputs from xml file. Will you please check it;s defined correctly.

      We (Ansys employees) can not download any files or provide specific and detailed help on convergence issues – perhaps some other forum memberrs can. Also if you have a commercial supported licence, then please feel free to open up a support request in our customer portal for detailed investigation of your case.

      For resoution of above  convergence error (unconverged solution: identified as 99999) , you can find multiple articles/helps on some of the searches.It's generic error.

      Thanks

      • Falconitexz
        Subscriber

        the only xml. data that i have for the project is for adding the material. Could it be a problem from using the shared topology, i formed 2 solid bodies into one part and i use shared topology for combining it. I dont think i need to give another "contact" between the two bodies. For the imported  force load, i exported the nodes number and location from the face to .xls file. Firstly i select the face as named selection and then i used this function "Create  Nodal Selection" from the named selection. I added two force in X and Y for each nodes and then import it again to Ansys using the External data in .csv file.

        Do you have any tips what can i try  at this point? I need to calculate vector principal stress from the whole workpiece.

    • Manish Dubey
      Ansys Employee

      Hi, 

      The error message indicate at node number 24628 has very high value for UX. This might be an indication of ill-conditioned stiffness matrix and can be due to insufficient boundary condition or improper load defined. Does the analysis runs successfully if you suppress the imported load and apply some other load type, just in case to check whether the isssue with load or contact definition. Does the same model runs fine if you use structural steel from the engineering data library in order to check if it is the issue with material modeling. You can also try with unshare topology option in spaceclaim and see if with automatic bonded contact creation runs fine with imported load. 

      Thanks

      Manish

      • Falconitexz
        Subscriber

         

        Hi Manish,

        thank you for the suggestions,
        i have tried to supress the imported load and create a new force load onto the top face of  the workpiece with 500N and the solution worked. But i dont know how could the imported load be a problem, in the summary it states number of source & target& nodes mapped all  have the same number and the number of nodes not mapped : 0.

        I tried also to change the material to structural steel and it worked also.

        I tried to use contacts instead of shared topology and it didnt work.

        I setup the initiap substep=200, min substep=25, max substep=10000; Large deflection = On;

        Here is some data of the alu that i use:

         

    • Manish Dubey
      Ansys Employee

      Its hard to predict what can be a problem without seeing a model. It can be a material modeling issue or share topology.

      1) Does unshare topology worked with imported load and nonlinear material model? - if yes then it might be issue with share topology. 

      2) Does linear material model worked for imported load and share topology option? - if yes then it might be material modeling issue. 

      You may need to try some nonconveregence diagnostics and see if that works, 

      Try with direct solver, susbteps looks fine and use stabilization (reduce energy dissipation ratio) under nonlinear controls.

      Thanks
      Manish

      • Falconitexz
        Subscriber

        Since i dont think you cant download the file even if i upload it here, could you help me to analyze what else could be the problem, or what other info do you  need, i can make a screenshot out of it.

        i just realized i did some typo on my last reply, what i meant i ve tried to use the contacts and use the imported load but it still doesnt work.

        And yeah i tried to change to the normal structural steel (which i think a linear material model) and it worked without problem.

        how can i do nonconveregence diagnostics? is there any video about this?

         

    • bhagwantP
      Ansys Employee

      Hello Falconitexz,

      one of the error message tells that element 19699 from upper body is having high distortion. Will you please check how is mesh over there. My initial suspect is either material modelling/ meshing issue (Upper body part).

      Thanks

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