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Steel Designers' Manual - 6th Edition (2003)
(1) the extension of a tie with low initial tension is considerably more than TL/EA.
(2) straight cables can be used for load carrying, but either the tension will be very
high or there will be large deflections.
Two-way cable net (Fig. 5.27)
Approximate calculations can be carried out by hand in a similar way to the single
cable calculations above. The basic equilibrium equation for two opposing cables is:
t1
t2
+ = P
R R
where P = load/surface area and t1 and t2 are the tensions/unit width, i.e.
t
1
1
T1
T
= t2
=
a a
1
2
2
2
where a1 and a2 are the cable spacings and T1 and T2 are the cable tensions.
The loads on ridge cables and boundaries can be estimated from resolution of the
cable forces if the geometry is known.
The full analysis of cable net structures is a specialized and complicated process
which requires specially written computer programs.The procedure involves the following
stages:
T2
a,
Fig. 5.27 Two-way cable net
T1
p
T1
Cable structures 195
T2
T
T2