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-   -   how to design a woven cable grid to support workers (http://www.dimcax.com/hust/showthread.php?t=25341)

huangyhg 2009-09-09 05:44 PM

how to design a woven cable grid to support workers
 
how to design a woven cable grid to support workers
i have an interesting design request from a client.
they would like to use a 2" sq. grid of cables to support workers within a large steel trussed ceiling space.
i have worked on assuming one-way action of 6 cables and using simple mechanics of materials, i have found that someting like 83# creates a tension of 300+k for a cable span of 9 feet.
does anyone have a f.e. program that can produce an output given that the mesh is: tension only, woven, not likely to be level when initially installed (minimal pretensioning), friction between the cables (woven).
as a side note, i gave the cable an initial drape of 2" and the tension in the cable after being loaded was in the 300# range.
let know if anyone has done this before..
-christopher
look up roarks.
there are tables in there giving the deflection and tension of a cable under point load.
you then only have to decide how many cables take the load.
300k is too high, but 2" may be a bit low. the formulii in roarks will give you something more realistic. i would expect more like 300lb.
another option is to have a continuous cable that has a pulley under each truss and is only fixed at each end. this will deflect more but will also avoid horizontal forces on the trusses.


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