Continue to Site

Eng-Tips is the largest engineering community on the Internet

Intelligent Work Forums for Engineering Professionals

  • Congratulations GregLocock on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

Stress Analysis vs Stability Analysis for Aluminium Dome Roofs (Space Frames)

Status
Not open for further replies.

Dome Design

Structural
May 10, 2019
8
Hello dears,
Firstly, I wish all eng-tips people a successful day. I am a junior civil engineer has started to construct space frames such aluminium geodesic dome roofs. I would to ask some questions to clarify them on my mind and helps to other people concerning about these subjects.
1.When I design a dome roof, API 650 Annex G refers to stress analysis for design. But as I know, stability analysis is a factor also for design of space frames. What do you think about it? when I compare these analysis on my dome, stability design requires more stiff sections means heavier sections.
2. For beams under compression, there are some effective lengths issues for buckling(Now, the table has came to ur eyes). Normally, for space frames which have pinned connections, effective length factor is 1. But fixed connections decreases. Since, dome roof beams connecting a node plate by bolts, I've thought that these beams have fixed connections. So can I apply effective length factor as a calculated for fixed connections?
Thanks for answering
 
Replies continue below

Recommended for you

I've seen the bolted struct connections, but I would guess they are still pinned connections and not designed as moment connections. Even if they were moment connections, it would take some careful thought to figure out what that did to effective length. Specifically, you'd have a moment connection to a hub plate, but what keeps that hub from rotating is just similar connections to other struts. So if the hub can rotate, the struts can buckle on each side without rotational restraint.

 
Status
Not open for further replies.

Part and Inventory Search

Sponsor