Seismosoft | Earthquake Engineering Solutions

As a new user trying to understand the detailed calculation of seismobuild and after reviewing the output report I would like to raise a couple of clarifications as I cannot find any detailed explanation to my questions:

1. does ϴu represents the chord rotation acceptance criteria as given in ASCE 41 table 10-7 and 10-8?

2. what do ϴs and ϴR represents?

3. How does the performance ratio calculated?

4. is there a way that the output can be presented in a tabulated format similar to midas gen or sap so that it is easier to browse through the results of all member?

https://www.dropbox.com/h

1. As specified in ASCE 41 the theta,plastic value is given by the tables.
Theta,u=theta,y+theta,plastic
2. Theta,R is the resistance and theta,s is the demand
3. It is the demand to capacity ratio.
4. In the Checks module the results are presented both in tabulated and visual (on the 3D plot) format with several filters. The tables can be easily copied an pasted to Excel. Further detailed results for particular members are also presented (by right clicking on each member on the 3D plot)
Seismosoft Support

Thank you Seismosoft Team for the explanation.

Follow up questions on the same topic.

1. Does ϴs (rotation demand) represents the total chord rotation?

2. How does ϴR (resistance) or capacity being calculated?

3. Is there any correlation between ϴr (resistance) with the plastic rotation capacity shown on ASCE 41 for a selected performance level?

1 Indeed, theta,s is the total chord rotation

2. You can output a report with detailed calculations from the Annex tab in the Report dialog box. Further, you may download the SeismoBuild Verification Report for ASCE 41-17 and the corresponding models from: https://seismosoft.com/seismobuild-documentation

3. yes. Theta.r is the sum of the yield capacity plus the plastic rotation capacity shown on ASCE 41

Seismosoft Support

To Seismosoft Support:
Do you have any practical example or information regarding how to use the Fardis - Biskinis formula fothe Chord Rotation?

Dear juansa,

In SeismoBuild the equations suggested by D. Biskinis and M. N. Fardis [2013] are employed for the calculation of chord rotation capacity in circular sections. You may export the report with the detailed calculation of chord rotation capacity in order to check how the abovementioned equations are employed.
Please note that we have a number of examples in SeismoBuild's Verification Reports available for download in https://seismosoft.com/seismobuild-documentation

Dear Seismosoft Staff

Does seismostruct also calculate the chord rotation (under the Post-processor option Element Action Effects ->Frame Deformations) the same way? That is does it calculate the chord rotation based on the sum of yield and plastic rotation?

Regards
Roshen

Dear roshen.rj,

The chord rotation found in the Post-processor>Element Action Effects >Frame Deformations is the demand for the elements of your model and not the capacity, calculated according to the Codes.

Thank you for the reply. So how is the chord rotation demand actually calculated in seismostruct? Is there an equation which seismostruct follows?

Dear roshen.rj,

The chord rotation, which is a member's internal deformation, is calculated based on basic engineering, like the member's internal forces.
The Appendix A - Theoretical background and modelling assumptions, available in SeismoStruct's User Manual might also help you.