I have a question about analyzing of diagrid structure and is related to structural engineering. does anyone know the numerical value of deflection amplified factor(Cd) for the diagrid structure of tall building?
Hi that sounds like the dimension based portion Cd of the dynamic amplification factor CsCd defined in the structural wind loading Eurocode EN1991-1-4: 2005 and potentially modified by the national annex in the country you are dealing with.
Cd is typically a little lower than 1, allowing for the fact that the worst gust wind will not hit the whole tower at the same time, whereas Cs is typically greater than 1, allowing for the increase in load due to inertial forces added to the direct wind load.
thanks for your reply.
I want to determine the limit value for the drift index based on the formula in the building code (according to the picture uploaded) and the table that is considered for the deflection amplified factor based on the structure type in Iran code of building but in that table I could not find the structure like diagrid .for example for the rigid frame structure with the height of 50, Cd factor is 4.5 and is not lower than 1.
Ahh I’m afraid I don’t know the Iranian building codes. You really need to find a structural engineer with experience of that building code : I doubt you will find one on here. Good luck with your search. You could revise the topic question to structural question : Iranian building code to attract more specific help…?
thanks for your help
in my building inter story drift index is suitable but deflections at top floors of the building are high. i am trying to find right value.