Error and no convergence

Dear All 

 

 

i need your advice and help in this case, i am modeling a T-shape offshore jacket joint  for Fatigue analysis but i have been faced with these errors and warnings

this is the picture of real test now i am trying to model it in ansys in order to get the same result then fatigue analysis they just had done the static analysis 

 

 

i do not know if it might be related to boundary condition or not!

i have defined the behavior of steel joints as a flexible 

then even i changed to rigid but I got an error again 

the boundary condition look likes to be  simple support not fixed, even i changed them respectively with  each other, i also used the displacement support but did not work 

the messages are :

 

 

please help and guide me ,

many thanks 

 

Comments

  • edited April 2019

    Hi,

    To debug pivot errors, please refer to the methods suggested in this post.

  • yasser1987yasser1987 Member
    edited April 2019

    many thanks  for the response

    i read your suggestion and I did some changes in the model in order to be much restrained but i have faced again with these two errors 

    i applied the force as a displacement in the Z direction and fixed the rest directions either rotational or translational

    at two sides of chord with respect to the experiment picture and to be real case i fixed translational displacement in X,Y,Z directions and rotational free 

     

     

    sorry sir , could you please do me a favor and take a look at the model maybe you will find out how to overcome the error 

  • yasser1987yasser1987 Member
    edited April 2019

    @peteroznewman

     

    Dear Peter 

     

    Do you have any idea how to overcome the problem?

  • peteroznewmanpeteroznewman Member
    edited April 2019

     Yes, follow all the steps that are in Sandeep's excellent post.

    Check your inputs for reasonable values. You have an obvious mistake in the displacement you input, it is 305 km!

    Delete Remote Displacement 2 because you have used 2 edges. Create two separate Remote Displacements, one at each end with one edge each.

  • peteroznewmanpeteroznewman Member
    edited April 2019

    Two other changes, under Analysis Settings, turn On Large Deflection and turn On Auto Time Stepping and set the Initial Substeps to 10. Here is the result for a displacement of 0.1 m.  I recommend using smaller element size in the mesh. This mesh is too coarse.

  • yasser1987yasser1987 Member
    edited April 2019

    Dear peter 

     

    Thanks a million, you are always helpful and considerate, even i will never ever forget your help for the geotechnical  problem Bucket foundation designing (however i could not overcome the errors and suspended so far) 

    Also thanks to  Sandeepmedikonda for his guidance 

     

     

    Regards 

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