converge in static analyze

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engnomran
Posts: 55
Joined: Fri Jul 04, 2014 9:57 pm
Location: International Institute of Earthquake Engineering and Seismology(IIEES)

converge in static analyze

Post by engnomran »

Hi every body
I have 2 questions about converege.
1-Why can number of step of static analyze change converge?
2-If number of step of static analyze change,why do responses change too?
For example
1-use
integrator LoadControl 1
analysis Static
analyze 1
2-use
integrator LoadControl 0.1
analysis Static
analyze 10

thanks
maksins
Posts: 32
Joined: Sun Jun 19, 2011 10:28 am
Location: University at Buffalo

Re: converge in static analyze

Post by maksins »

In the first case you are performing the static analysis in one step. The tangent stiffness at the beginning of the analysis is used.
In the second case, you are performing analysis in 10 steps, the tangent stiffness at the beginning of each step that is closer to the instantaneous tangent stiffness is used. Hence better convergence.
Convergence aside, for implicit methods, the final results should be the same.
Manish Kumar
Department of Civil, Structural and Environmental Engineering
University at Buffalo, The State University of New York

http://www.manishkumar.org
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