Periods at RSA

[Pandelis1998]

Dears,


I am using Seismostruct 2020.


At the modal analysis I am using two different ways to calculate the cracked stiffness :


a)Calculate Cracked Stiffness from user defined ratios.


b)Calculate Cracked Stiffness from My/θy ratios.




Although I observe at the results of response spectrum analysis : the periods ,which have taken into account, are the same with the modal analysis only if I use the first way (Calculate Cracked Stiffness from user defined ratios).




For example using Cracked Stiffness from My/θy ratios the period results in response spectrum analysis are way different from the periods which were given from modal analysis (using Cracked Stiffness from My/θy ratios).




I want to use response spectrum analysis using periods from cracked Stiffness from My/θy ratios.
So what I should do about that?




Thank you in advance for your help.



Sincerely,
Panteleimon Gkagkoulis
Under/ate student UoP

[z.gronti]

Dear Pandelis1998,

We always advise Seismosoft users to use the current version of the programs due to the fact that new features are added and bugs are fixed. THe current version is SeismoStruct v2021- Release 3.

However, the reported bug in the RSA when using Cracked Stiffness with My/θy ratios exists in the current version also. The bug will be fixed in the upcoming release.

[z.gronti]

Dear Pandelis1998,

Please download the current version of SeisoStruct v2021-Release 3-Build 2 with the reported error corrected.