I'm getting the below error. Please let me know the possible causes. My model has 550 thousand elements. Is it due to the size of the model? The solution has diverged for the very first increment.
FATAL ERROR E5001: NON-POSITIVE DEFINITE DETECTED AT GRID XXX COMPONENT X
WARNING G3012: - ELEMENT - HAS A SKEW ANGLE GREATER THAN - (104)
WARNING G3014: - ELEMENT - HAS AN INTERIOR ANGLE GREATER THAN - (10)
WARNING G3015: - ELEMENT - HAS AN INTERIOR ANGLE LESS THAN - (98)
WARNING G3051: MODIFYING POSITION OF SLAVE GRID - ON CONTACT ELEMENT - (4133)
WARNING E5005: STIFFNESS MATRIX SINGULAR OR NON-POSITIVE DEFINITE (1)
WARNING E5075: BISECTING CURRENT LOAD INCREMENT (5)
WARNING E5077: DIFFERENTIAL STIFFNESS MATRIX IGNORED FOR THIS ITERATION (1)
WARNING E5078: SOLUTION HAS DIVERGED (5)
FATAL ERROR E5001: NON-POSITIVE DEFINITE DETECTED AT GRID - COMPONENT - (1)
The message is basically about singularity issues. Here is list of questions to be considered.
Have you tried a linear solution to verify your model?
Is your model constrained all for all 6 rigid body motions?
Do you have poorly shaped elements in the mesh?
Do you have contact or glue defined? Is it required for stability and is it set up properly?
How many load increments or time steps did you specify? You may be applying load steps that are too large.
If you would like to send the model in, we can take a look at it. If we can't figure it out in the FEMAP group, we can pass it to the NX Nastran team for evaluation.
sherman dot mark at siemens dot com