How to design a woven cable grid to support workers

[TSSEngineer]

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

 

[csd72]

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.