activation time/L.F

[zthaer]

dear all;
i m trying to add some vertical wide-column to existing structure;
i made the Eigenvalue analysis with activation time 0.01 for these new shear wall and i observed that the natural period does not changed , which is expected since the new shear wall is not activated in this stage
then i used the modal displacement for the dominant mode to push the new structure
but when i push the structure the analysis is terminated within the few steps with ( fbd_Tol) message ( just after first pushover load increment)as follows:
"
Estimated size of output file: 148624 KB


Permanent Loading
-----------------------------------------

LF= 1.00000, LF_incr= 1.00000 (Iter: 1 => Converg)


Variable Loading
----------------------------

Phase No. 1
Type of Control: Response Control
Controlled Node: n29h4
Controlled Direction: y
Target Displ.: 0.2
Steps: 100
Disp_Incr= 0.00236, LF= 0.96732 (Iter: 1 => Converg)
Disp_Incr= 0.00200, LF= (Iter: 0 => fbd_Tol)
Disp_Incr= 0.00025, LF= (Iter: 0 => fbd_Tol)
Disp_Incr= 0.00003, LF= (Iter: 0 => fbd_Tol)
"
i change the activation time to the default value and it works so
1) what is the problem with that ?
2) i observe zero increment load at the top of these new elements, does that accurate or do i need to activate these elements to account for their stiffness distribution for selected period.

any help please ??
best;

[z.gronti]

Dear Thaer,

Please try to delete the shear wall elements (with the different activation time) and check if the analysis is completed. If it is not, then you should check your model and if it can stand the applied loads.

[zthaer]

dear zoi;
i got the problem solved by increasing number of steps but
i got a very weak response even lesser than the original structure
please any help;
best

[seismosoft]

Zthaer hi,

Note that this is a forum about Seismosoft's programs, rather than a general forum on earthquake engineering. Hence, issues related to your reasearch should be discussed with your supervisor. Note also that, being a small company, we cannot provide personalised technical support to each one of our thousands of users.

Regards,
Seismosoft Support