# RE: Cable Problem

• To: <seaint(--nospam--at)seaint.org>
• Subject: RE: Cable Problem
• From: "Brian K. Smith" <smithegr(--nospam--at)bellsouth.net>
• Date: Wed, 5 Sep 2001 09:14:30 -0500
```>From Table 12, Case 5, Roark's Formulas for Stress and Strain, 6th Edition

W = Load @ mid point
P = Tension in Cable
Theta = end rotation

Tan (theta) - sin (theta) = W/(2EA) or if theta < 12degrees, theta =
(W/(EA))^(1/3)

P = W /(2 tan (theta))

Depending upon how large your P value is, you may need to consider your
reduction in cross sectional area when using these equations.

Brian K. Smith, P.E.

-----Original Message-----
From: W. Gray Hodge [mailto:ghodge(--nospam--at)hodgedesign.com]
Sent: Tuesday, September 04, 2001 3:26 PM
To: 'seaint(--nospam--at)seaint.org'
Subject: Cable Problem

Can anyone tell me (or direct me to a good resource) how I calculate the
sag and resultant tension in a cable due to a point load, given the
distance between end supports, the cable properties (Area and Modulus of
Elasticity), the initial tension in the cable and the magnitude and
location of the point load along the cable.  I am assuming that the ends
of the cable are at approximately the same elevation.

Gray Hodge

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