Torsional irregularity prevails in the 1st mode

E

etriye

New Member
hi friends, in a project, there is torsional irregularity in the first mode. .. what would you recommend for this project?
 
"etrie":1ve5cyfb" said:
I added the project as msg but it didn't work, I added it now, thanks for your interest
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I couldn't open it because it's a demo version, so I can't help
 
It is normal for the mode shape to be torsion in the 1st mode. may be. Torsional irregularity is another matter. I am making this comment in general without looking at your project.
 
It is normal that there is torsion in the 1st mode. In 5% of the regulation, in the project in question, the torsion in the 1st mode is dominated by the rz at the order of 80%, does this not cause a problem? so the building doesn't start to move with direct torsion?
 
Hi, According to your model, it is completely normal for torsion to be active in the first mode. If you do not want torsional irregularity in the model, I recommend you to reinforce the system with curtains that spread to the corners in Y direction. The structure is long in the X direction and your frames are short and discontinuous in the y direction. Also, I imported your system to sap2000. I am attaching the deformation of the first three mods to the message as screenshots. I got the deformation magnification ratio the same in both programs. 1st mod: 2.mod: 3.mod: Periods : In addition, when adding basement perimeter curtain, the ratio of 0.75 your question: According to TDY, they are exempt from the R coefficient. For this, you must assign the rigid basement number as the appropriate floor number in the project settings in the program. For the ground floor, this value is zero.
 
"etriye":16grgug1" said:
hi guys, in a project done, there is torsional irregularity in the first mode. base total shear force 0.75 error is in question... what do you recommend in this project
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1st mode will be torsion, 2nd mod ry, 3rd mod rx... you confused me for an hour how is rx in this system I said it could be, I checked it... it kills when you say 5% additional eccentricity in thin and long structures, it kills it officially... according to the regulation, it is almost impossible to pass the A1 irregularity... even in symmetrical structures, A1 comes out unfortunately. Also, I transferred it to sap2000 and said something like this. I looked at it... there seems to be some deficiencies in the transmission....respx was not included in the combination and its coefficient was not entered as 1/r. Direct masses and earthquake loadings were automatically taken from the idea... I think this is equivalent earthquake load... dat them to sap It would be better to give it at the input a and have the handle calculate it... if the tiles were also delivered and the mass was transferred to the handle in the form of g+0.3q in the mass source... it would be nicer if the dimensions of the elements were given, not the properties... I can't understand if they are all other, insertion points... but still it's nice to be able to transfer data to the handle even in the demo version... still I want it to be improved. also the rz's in the handle and ide don't match. rz in ide 0.83 in 1st mode, 0.24 in sap... zero in 2nd and 3rd mode in ide... 0.46 and 0.12 in sap respectively... the sums of the first three modes are close to each other...
 
I also transferred it to sap2000, sap2000 respx and ide respx, and the respy results were the same. Also, the other results are the same. In which account is this Rz used? Response results were the same for the elements. Respx is defined in combinations, what does the Rz value do for us in the next step?
 
"HakanŞahin":4d1njpbb" said:
kills it when you say 5% additional eccentricity in thin and long structures... according to the regulation, it is almost impossible to pass the irregularity of A1... even in symmetrical structures, A1 comes out unfortunately.
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sir when you say hit it, it kills... I agree with what you said, I transferred it to the handle, the dimensions of the elements are not visible, only the definitions have been made, but I hope it will be done over time.
"curious":4d1njpbb" said:
what does the Rz value do for us in the next step.
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As far as I know, rz in the first mode is not desired as far as I know, and I know it doesn't pass through the room, correct me if I'm wrong?
 
"curious":tchmlhvf" said:
I transferred it to sap2000, sap2000 respx and ide respx, and the respy results were the same. Also, the other results are the same. This Rz is used in which account. Response results are the same in the elements. Respx is defined in the combinations. What is the value of Rz at this stage?
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It is useless by itself. Our aim in performing dynamic analysis is to reach extreme forces and displacements in the elements of the structure by taking the contribution of a sufficient number of modes. The result of dynamic analysis ( response spectrum ) with ideCAD, extreme forces and displacements , it turns out exactly the same as the values calculated with both sap2000 and Etabs and other international programs.
 
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