Civil Engineering/Diaphragms


Good Morning sir
Could you please explain about the use of diaphragm in ETABS. What will happen if we do not assign it for analysis of building?

Thanking you!

Dear Niranjan

RC slabs are stiff slabs which constrain the joints of  each story in structure to move together. Then this is a structural must that you model your slabs in each story so that the integrity of the structure in each level be kept within a margin. A diafragm in etabs or sap make a simple method to model your structure behaviour in each level. If you dont do that the latel loads will be absorbed by side elements of the structure i.e the closest elements to the loading points. You may test this notion very easily, by comparing the results of two models with lateral loading , one with diaphragm and the other without it.


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Babak Esmailzadeh Hakimi


I can answer questions in Structural Engineering, Earthquake Engineering, Project Management and Project Control topics!


I am experienced in the area of earthquake engineering in electrical power industry, i.e. Lifeline Earthquake Engineering. My focus has been on structural seismic design of power installations. Recently I have got involved in project management in the category of constructional engineering.

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Bs degree in Civil Engineering from Ferdowsi University ,1988, Mashhad Iran, Ms degree in Earthquake Engineering, Sharif University of Technology, 1993, Tehran, Iran

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