For basic information about convergence, see ATENA Troubleshooting, sections 2.2.2 I get the message "The execution is killed due to violation of stop iteration criteria", what does it mean? and  2.2.6 Floating point problems - Division by zero, Loss of >7 digits on the matrix diagonal, Warning: Sign of diagonal changed when reducing equation, Floating point exception: Multiple floating points traps, Zero or negative jacobian, InvertA: zero determinant, CCMaterials Extended AExc: CC5ParamYield F:project_stress_on_f_division by zero, and similar

I am running a large model. I couldn't use fine mesh size as it takes forever to run. However I defined load steps with very small increments.

In very few steps the convergence criteria numbers are high ( criteria No. 3 value: 4, 1,0 and 0.4). What does the criteria mean? It seems that  the analysis was not converged at the end of specified iterations. I couldn't go for larger number as it takes forever to run.

Do you think the results are reliable?  The deflection is gradually increasing and it does not show a sign of sudden increase due to failure, concrete and reinforcement stresses are within the capacity. Therefore, the structure may still working within the capacity.

I look forward to hearing your advise.

kind regards,
Siavash