The OpenSees Community

When i used the fiber model this is the model i used for the steel and after that the analysis script am using set Fy [expr 420*$MPa]; # STEEL yield stress set Es [expr 200000*$MPa]; # modulus of steel set Bs 0.01; # strain-hardening ratio set R0 20; # control the transition from elastic to plastic ...

Forgot to mention am coming from there cause my model modeled as fiber has convergence problem for some seismic records that am scalling, thats why i wanted to go one step back and specify the capcacities.

Hi am defining a beam section using the following command. The problem with this is that it sets the beam with the same steel top and bottom, and i want to set different at top and at bottom. How can i do this? set EIBeam [expr $Ec*$IzBeam]; # EI, for moment-curvature relationship set EABeam [expr $...

Could the problem be the cover concrete that is failing? but this shouldnt be happening rigth, it should fail til the core fails or the reinforcement.

HI. what does the first part of the script means? thanks > #change to reach convergance > variable TolDynamic 1.e-3; # Convergence > Test:tolerance > > #define your GM intensity step: 0.1g,... > set s [expr 2+4*$i] > set gmf [expr $s/10.] > > puts "gmf=[expr $gmf]" > puts *****************...

I get this error when runing a time history analysis
UniaxialMaterial::setTrial() - material failed in setTrialStrain()
Large trial compressive strain

what does this means?

Does the same applies to time history analysis where my model are fine cause i have checked them with static and modal analysis , but for some reason the analysis doesnt always converge, even when am using routines that are available in the wiki, i tried changing dampening the modes considered, the ...

I recently download this example http://opensees.berkeley.edu/wiki/index.php/OpenSees_Example_5._2D_Frame,_3-story_3-bay,_Reinforced-Concrete_Section_%26_Steel_W-Section, I downloaded the fiber RC model and the push over, and it says it wont converge for certain points but completes te pushover, tis...

If am not mistaken what you are mentioning is what i already have the rotation at the gauss point since it a zerolegth element corresponds to the curvature non the rotation of a portion of the element wich is what am looking for. What i want is to obatain the rotation of lets say i define that my hi...

I there is a way to obtain the rotation of a portion of the element without using springs? I currently have moment curvate, but i would like to obtain the rotation of a portion of the section, is this possible or this involve changing the element tipe?

Hi am trying to perform a transient analysis, but am having problems with the damping. I started using Kcommited but this would converge, change it to 0.05 xDamp and used Kinint it worked, now i want to use xDamp 0.02 and it wont converge. what could be the problem? Here is the script am using # RAY...

Thanks that's what i thougth.

andreascj wrote: > The periods are different because SAP uses "effective stiffness" > to perform eigen analysis while OpenSees will be using your "initial > stiffness". Make your "effective stiffness" in SAP = > "initial stiffness" in OpenSees and see. Just on...

Hi: am modelling impact with a zero length element, but when i run the model i get force 0 in all directions but displacement different than zero in the zerolengthelement, the displacement of the structure is enough to activate the element but i cant find why the element doesn't seems to work. Is th...

Thank you, thank you thank you!! you just saved my life.
I did what you told me and i worked.
"effective stiffness" in SAP = "initial stiffness" Open Sees