I am doing pushover analysis for 12 story RC frame using SAP2000 and defined hinges properties automatically from ASCE 41-13 tables after designing the frame using response spectrum and still face this warning, So I hope someone helps me to overcome this problem.
Mohammed Al-Haaj it seems like a convergence problem first. You can start with the process increasing the convergence tolerance in Sap2000. In addition, I got the same problem before in Sap2000 V16, I tackled it promoting the version to V19 which deals with convergence better. Also, your problem may stem from your structure model if it is unstable. In this case, I suggest you to make sure that the model is generated correctly and no overlapping of elements exist.
Hi Mohammed,
I agree with Kultigin, it seems like you have a convergence problem. First check your columns hinges. Second try to reduce your time steps by adjusting your nonlinear parameters. Also try to set the value of the "Maximum Null steps" equal to the maximum total steps. I hope this will solve your problem.
Good luck!
Thank you all Kultigin Demirlioglu , Ayman M. El Ansary , Ola Adel Qasim and
Kamran Khalifehei
for your answer,All of you are right ,I tried to follow your suggestions but didn't solve the problem .
finally I found out the problem, When I was define the hinge properties automatically, the convergence problem was appear but when I defined the hinge properties manually with the help of section designer and moment curvature curve in SAP2000 the problem solved .
Mohammed Al-Haaj sir i am also facing the same problem, so have you used sectional designer and moment curvature to solve this issue
Mohammed Al-Haaj Defining the hinges manually solved the problem for me, Thank you sir.
Javad Esmaeelpour Hi! I experienced the same problem. May I know what software did you use to manually define hinge properties?
Mohammed Al-Haaj Hi, i recommend you to run your model with standard solver first to identify instability issues if there are any, then change the solver to multi-threaded solver.
from NL load case (POA) change solution strategy to event to event and put null step and total step to zero each event and step depend on its size to make maximum some of steps to 1
I hope above helps !
I solve this problem either by:
1. Increasing maximum number of steps and null steps
2. Changing from Final state only to Multiple steps in "Results saved" and allowing to save positive and negative displacement increments
3. Changing from Iterative event to event, to Event to event only in "Nonlinear parameters"
Manuel Urueña Palomo How does one increase the number of steps in the POA in SAP?
Omoniyi Moses Tope
In load case or load pattern, modify options.
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