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Seismic Eccentricity isn't taken into account !

4 REPLIES 4
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Message 1 of 5
Mohammed_Ata
322 Views, 4 Replies

Seismic Eccentricity isn't taken into account !

I have already defined multistory building with seismic loads with eccentricity is 5% ( i understand that the 5% is from G-center of gravity-) . 

After calcualtions , i opend "diagrams for building " from results menu . I showed the force and center of gravity(G).I found the the force is applied at G !! where is the eccentricity that i have defined ? 

 

This is shown in the attached picture . 

.

original.png

4 REPLIES 4
Message 2 of 5
Rafal.Gaweda
in reply to: Mohammed_Ata

I found the the force is applied at G !! where is the eccentricity that i have defined ? 

 

 

Eccentricity is not displayed graphically.

Only taken into account for caclulations.



Rafal Gaweda
Message 3 of 5
Mohammed_Ata
in reply to: Mohammed_Ata

I hope this topic is solved ( to be show graphically) in the next update . 

Message 4 of 5
Rafal.Gaweda
in reply to: Mohammed_Ata


I hope this topic is solved 

 

It is not a bug. It is just like that.



Rafal Gaweda
Message 5 of 5
Tuctas
in reply to: Mohammed_Ata

Actually, the eccentricity doesn't result to the shifting of the seismic force. If you choose the option that you showed in your attached picture, then the mass matrix is shifted and not the point of application of the seismic force. The only case that there is no shifting of the mass matrix is when in the analysis type "modal with automatic definition of seismic cases" the option of "simplified approach" is chosen, where the pseudostatic horizontal forces are implemented in parallel with seismic moments. 

Furthermore, when you choose to implement a diaphragm through the option "rigid connection of nodes for the slab" in the Panel calculation model by selecting "stiffening diaphragm" (flexible or rigid body) without F.E, then there is no shifting at the mass of the panel that correspond to its self weight (that is the only mass of the panel concetrated in the C.M) ..! Once, it was a bug in Robot, i am not sure if it is already solved. 

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