10-02-2010, 06:50 AM
Dear civilphongvan [ Post: #102 ]
ETABS use 'terminology' center of mass & center of rigidity.
In 'lateral load resistant system', you must add 'eccentricity'
Eccentricity simply can be said as distance from center of mass to center of rigidity.
For simple & low rise building 5% additional eccentricity is enough for design.
As additional, rigid diaphragm, when you assign it, it have meaning all the element of structures that you select to be added with 'rigid diaphragm' ( could be slab, beam, column & wall : you see at building plan then select then add diaphragm ) will move all together when lateral load applied to your structure.
To set your own calculation of lateral load you can use 'static user load', in this option you can set your loads + the eccentricity
Thanks
Paladin
ETABS use 'terminology' center of mass & center of rigidity.
In 'lateral load resistant system', you must add 'eccentricity'
Eccentricity simply can be said as distance from center of mass to center of rigidity.
For simple & low rise building 5% additional eccentricity is enough for design.
As additional, rigid diaphragm, when you assign it, it have meaning all the element of structures that you select to be added with 'rigid diaphragm' ( could be slab, beam, column & wall : you see at building plan then select then add diaphragm ) will move all together when lateral load applied to your structure.
To set your own calculation of lateral load you can use 'static user load', in this option you can set your loads + the eccentricity
Thanks
Paladin