mass problem in ETABS

[citywall]

Hello friends,
I encountered a problem with ETABS on calculation of story mass.
The mass output doesn't match my hand calculation, 80% more.

A testing run in my friend's company gives the same outcome.

Has anyone found this problem? How come?

Thanks.

Tony

 

[sbouvia]

There are a couple of things wrong with your question.

1. It has no specific information on what the building is.
2. There is no model or any information on what you have modeled in ETABS. (Garbage in Garbage Out)
3. This might be a better posting in the Computers and Structures section, however it will get answered here.

Are you stating that the mass that ETABS comes up with is 80% more than your hand calculation or that your hand calculation has 80% more mass? I think this is a problem with the model and not the program, I would go back and look at what you are using to define the mass rather it just be member weights and additional mass or if you are using the mass from specific load combinations.

Scott B.

 

[citywall]

ETABS counted twice of self weight. I defined the mass from [highlight #F57900]self[/highlight] and specified mass and loads.

Thanks man.

Tony

 

[PicoStruc]

. I defined the mass from self and specified mass and loads.

Note : Self is generally already inclueded in deadload depending of your load pattern settings ! be cautious !

 

[johnbridge231]

Remember to check the Modal Participating mass ratio from the Display->Show tables menu item.
It should be enough (>90%) to match your hand calculations.

Analysis and Design of arbitrary cross sections
Reinforcement design to all major codes
Moment Curvature analysis

http://www.engissol.com/cross-section-analysis-design.html