why do we provide eccentricity ratio for diaphragm while defining earthquake load

[curiousinvite]

why do we provide eccentricity ratio for diaphragm while defining earthquake load(static and response spectrum ) analysis
Is it to consider torsional efect due to difference in cm and center of rigidity
what will happen if i dont consider eccentricity ratio

 

[Agent666]

Accidental eccentricity accounts for a mix of an uneven distribution of mass in real structures, and/or torsional ground motions and/or differences in real response vs estimated responses in engineering analyses.

Is it to consider torsional efect due to difference in cm and center of rigidity

No, accidental eccentricities are accounted for in addition to this fundamental response.

what will happen if i dont consider eccentricity ratio

You're potentially underestimating the seismic demand in your lateral load resisting system.

https://engineervsheep.com

 

[curiousinvite]

SO what's etab's eccentricity ratio while defining load pattern?
what if i input higher ratio , does that mean if i now design it will design for higher torsion due to more eccentricity?

 

[Agent666]

Put the eccentricity ratio in as per the requirement of your local design code.

what if i input higher ratio , does that mean if i now design it will design for higher torsion due to more eccentricity?

Yes.

https://engineervsheep.com