Guyed Stack supports

[mark416]

Will anyone have any information for design of a guy wire supported stack. I have this publication name, but I can not find it any where. Any and/or all help will be great.
Thanks,
M.


A Design Procedure for Guyed Stacks Applying Non-Linear Cable Mechanics, by N. Gilbert, Y. M. Chokshi, Foster Wheeler Energy Corporation, Houston, TX.

 

[rb1957]

are "Foster Wheeler" still around ? ... maybe they could help ?

 

[crisb]

Probably in a journal around 1982?

http://ntlsearch.bts.gov/tris/record/tris/00683636.html

 

[rb1957]

fwcDOTcom are around, they have a section on technical papers, searching in there might help (but i haven't the time)

 

[mark416]

I have found a report in the AISC Journal; "Analysis of Cables as Equivalent Two-Force Members" DAVID H. H. TUNG AND ROBERT J. KUDDER.

I have not had time to review it, but basiclly the report states:
"Problems commonly
associated with cables, such as stresses (and change of sags)caused by a change of temperature or superimposed loads, or resulting from relative displacement of supports, can be readily solved by this method. It should be noted that the proposed procedure is also applicable to the analysis of transmission lines."

Has anyone read or know about this method? If so, any comments or feedback.
Thanks,
Mark.

 

[BarryEng]

Have you had a look at 'tubular structures' by Troitsky (one of the Lincoln welding series).

It includes a section of guyed strucrures.

 

[chicopee]

Good section on subject matter as pointed out by BarrEng.

 

[mark416]

BarryEng/Chicopee and all;

I just got that book from Lincoln and it' great.
I have been following the worked example for guyed stacks and unfortunately I'm having a hard time with the first step in calculating the Sf term (the shear force at piont F of the stack by the contribution from cables only). The example states "Sf=2.49+2.49=4.98 kips (see Part 5.2)".

How do you find this 2.49 when you need to go to Part 5.2 (the next step) where it seems that some of Part 5.2 has been calculated in Part 5.1. But to calculate Part 5.1, you need to have the information from Part 5.2.

How do you calculate this Sf??????

Thanks,
Mark416.

 

[chicopee]

I have the second edition and the example cited by you is section 6 of multilevel guyed stack. The book shows Q for fa as 2.27Kips and for fc as 2.49kips but look at the statement in parenthesese stating 2.49kips approx. the same as fa. Therefore Sf is taken as the sum of 2.49 for ea cable instead of 2.27 and 2.49 kips.

 

[mark416]

I see where the 2.49kips come from, but how do you calculate it? For cable fc, Q = Qwind + Qinitial tension = 0.22+2.27 = 2.49 kips. I don't have a problem calculating Qwind, I do not know how they calculated Qinitial tension for cable fc. Even though, it says it's approx. the same as in cable fa, I still don't know how they calculated Qinitial tension in cable fa = 2.27kips + the wind load = 2.49kips.

To get the 2.27kips for cable fa, you need to know that Sf = 2.49+2.49=4.98kips because that is used in calculating the deflection (Y). Y is then used to calculate the sag, and then the sag is used to calculate "component n of w, perpendicular to cable fa". And that is then used to calculate the 2.27kips. And that 2.27kips + wind = 2.49kips.


Does this make sense? It's as if you need to a value from fa to calculate fc, but you need that same value from fc to calculate fa. I'm just not seeing it.

Thansk.
Mark416.