Estimation of Fundamental Period of Vibration of a Structure
Estimation of Fundamental Period of Vibration of a Structure
(OP)
Hello!
I'm just confused regarding the appropriate approach on how to obtain the fundamental period of a structure using computer software. I am aware that there are approximate methods / formulas provided on many design codes (i.e.,IBC and ASCE) but I want to be clear to myself that I am certain of what I am doing when I use these programs.
In determining the period of the structure, do I have to include Live Loads or I only use DLs and structure selfweight?
For seismic design, I use the Effective Seismic Weight (see ASCE 7-05 Sec. 12.7.2) in obtaining the period of the structure? Am i correct? [Note: Eff. Seismic Weight includes portion of LLs for areas used for storage + snow load. Both of which are not DLs.]
Is the fundamental period to be used in seismic design different from the period for wind design? or can I use the period I obtained from seismic and apply to wind?
Please state your references if you have any. Just a noobie here.
Thanks!
I'm just confused regarding the appropriate approach on how to obtain the fundamental period of a structure using computer software. I am aware that there are approximate methods / formulas provided on many design codes (i.e.,IBC and ASCE) but I want to be clear to myself that I am certain of what I am doing when I use these programs.
In determining the period of the structure, do I have to include Live Loads or I only use DLs and structure selfweight?
For seismic design, I use the Effective Seismic Weight (see ASCE 7-05 Sec. 12.7.2) in obtaining the period of the structure? Am i correct? [Note: Eff. Seismic Weight includes portion of LLs for areas used for storage + snow load. Both of which are not DLs.]
Is the fundamental period to be used in seismic design different from the period for wind design? or can I use the period I obtained from seismic and apply to wind?
Please state your references if you have any. Just a noobie here.
Thanks!






RE: Estimation of Fundamental Period of Vibration of a Structure
If the weight/mass is the same and distributed the same under a wind event then the fundamental period will obviously be the same. Only if the mass or distribution of mass differs or different effective section properties are required to be considered between wind and seismic events will the period differ.
RE: Estimation of Fundamental Period of Vibration of a Structure
So what you're saying is that if my structure happens to be a wind-governing case (seismic usually ignored) for industrial facilities, then I still have to utilize the provision in seismic design in ASCE determining the effective seismic weight to obtain the fundamental period of the structure?
RE: Estimation of Fundamental Period of Vibration of a Structure
http://www.structuremag.org/article.aspx?articleID...
RE: Estimation of Fundamental Period of Vibration of a Structure
In this case I apply the provision for period determination by obtaining it through a "properly substantiated analysis" but I don't know what load to apply.
RE: Estimation of Fundamental Period of Vibration of a Structure