• Registered: 2014-01-15
  • Posts: 9

Topic: convergence

Hi there,

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

Quote Post 1

  • dpryl
  • CC software developer
  • Offline
  • Registered: 2007-07-13
  • Posts: 1,107

Re: convergence

Hello, please see ATENA Troubleshooting, 2.1.21 The analysis runs too long for general ideas how to reduce the analysis time.

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

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Quote Post 2