Non-linear thermal buckling 2

[skr3178]

Hello,

I am working with a plate with zero translation boundary conditions at both ends and application of loads in the form of thermal predefined temp. from 250 to 450 deg. C. Thermal coeff of expansion has also been defined for the material.
INP files:
Linear:

https://gofile.io/d/0ZZCJt

Non Linear:

https://gofile.io/d/CqJlrF

Procedure I have followed:
Job 1: Run with "buckle step" to determine various eigenvalues
-Added to keywords
*Output, field, variable=PRESELECT
*NODE FILE
U

Job 2: Run with "Static Riks" to determine post buckling behavior using the Job-1 output
-Added to keywords
**
*IMPERFECTION, FILE=Linear_Buckling, STEP=1
2,28.0
**

I am getting an error-"A ZERO DISPLACEMENT SOLUTION WAS FOUND IN THE FIRST ITERATION OF A RIKS STEP. THE ANALYSIS CANNOT PROCEED. THE MOST LIKELY CAUSE IS THAT ALL DISPLACEMENT DEGREES-OF-FREEDOM ARE CONSTRAINED TO BE ZERO. Job Nonlinear: Abaqus/Standard aborted due to errors"

I expect the structure to continue with post buckling from the non linear analysis as the thermal expansion would build the stress into the constrained ends. I would appreciate your inputs on this error.
-skr3178

 

[FEA way]

Check the documentation example "Buckling of a simply supported square plate". It features thermal loading case solved using Riks method and may be helpful for you.

 

[Mustaine3]

The material you are using in the nonlinear analysis has no expansion coefficient, so nothing is happening.

I would also recommend to request temperature output to see the current value, check you definition of imperfection and not to use C3D8R elements with one element through thickness in bending-dominated deformations.