Non-convergence due to "time increment is less than minimum specified"

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Non-convergence due to "time increment is less than minimum specified"

gpc.goog
Dear friends
 

 I am back to using Abaqus after a very long break from it. I am using Standard now.
 

 I am running a relatively simple problem where I am applying a pressure load on  one surface of an almost circular plate. The plate consists of several layers of different materials but they have common nodes so there are no contact issues. The plate is connected to a ring around the periphery of the plate through constraints at certain points which are primarily bolt holes. The bolts have NOT been modeled. Instead, constraints have been created using a reference node at the center of the bolt which is connected to all nodes in the bolt hole through a tied constraint. There are enforced displacements all around the periphery of the ring.
 

 I have used solid elements (C3D6 and C3D8R) only.
 

 Abaqus is able to apply about 50 % of the pressure load and stops with a time increment error.
 

 The residual force and moment are very small in the last attempted increment. Understandable, given the small time increment.
 

 Any help in getting the analysis to converge will be great!
 

 Thank you
 Guru
 

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Re: Non-convergence due to "time increment is less than minimum specified"

George Papazafeiropoulos
Dear Guru,
 

 The first thought that comes in mind is that there may be some kind of failure of the plate in the case that you have used nonlinear material. Is the analysis static?
 

 Best regards,
 _______________________________________________
George Papazafeiropoulos
Captain, Infrastructure Engineer, Hellenic Air Force
Civil Engineer, M.Sc., Ph.D. candidate, NTUA
Email: [hidden email]

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Re: Non-convergence due to "time increment is less than minimum specified"

Martin Bäker
In reply to this post by gpc.goog
have a look at this:

https://arxiv.org/pdf/1811.05753

On 12 Jan 2019 19:42:09 +0000
"[hidden email] [Abaqus]" <[hidden email]> wrote:

> Dear friends
>
>
>  I am back to using Abaqus after a very long break from it. I am using Standard now.
>
>
>  I am running a relatively simple problem where I am applying a pressure load on  one surface of an almost circular plate. The plate consists of several layers of different materials but they have common nodes so there are no contact issues. The plate is connected to a ring around the periphery of the plate through constraints at certain points which are primarily bolt holes. The bolts have NOT been modeled. Instead, constraints have been created using a reference node at the center of the bolt which is connected to all nodes in the bolt hole through a tied constraint. There are enforced displacements all around the periphery of the ring.
>
>
>  I have used solid elements (C3D6 and C3D8R) only.
>
>
>  Abaqus is able to apply about 50 % of the pressure load and stops with a time increment error.
>
>
>  The residual force and moment are very small in the last attempted increment. Understandable, given the small time increment.
>
>
>  Any help in getting the analysis to converge will be great!
>
>
>  Thank you
>  Guru
>
>


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Re: Non-convergence due to "time increment is less than minimum specified"

patrick Grossman-2
In reply to this post by George Papazafeiropoulos
 do you have any messages in the .msg file that may indicate rigid body motion?  have you looked in the visualizer diagnostics to see which nodes are not converging?

    On Tuesday, January 15, 2019, 6:57:13 AM EST, [hidden email] [Abaqus] <[hidden email]> wrote:

  

Dear Guru,
The first thought that comes in mind is that there may be some kind of failure of the plate in the case that you have used nonlinear material. Is the analysis static?
Best regards,_______________________________________________
George Papazafeiropoulos
Captain, Infrastructure Engineer, Hellenic Air Force
Civil Engineer, M.Sc., Ph.D. candidate, NTUA
Email: [hidden email]