# How does a cable/ wire bend?

1. Nov 4, 2012

### dazzler77

Hi I have a cable that is fixed at 2 points, and I would like to model the curve that it bends as the two points move together and further away.

In one scenario, the cable is fixed at both ends (one above the other) like a "C".
In the other scenario, both ends are also fixed in clamps, but it is like an "S"

Is there a formula to show what the curves might look like ({x,y} = z), given some stiffness or minimum bend radius? Is the "C" curve like a cosh

or is there some software that might simulate this? do I need finite element analysis? or is there a simplified estimate?

2. Nov 4, 2012

### Simon Bridge

3. Nov 4, 2012

That brings back bad memories. Solved those equations for an assignment at uni. Although we had to derive the second order non linear equation for the rope, wish I knew the equation beforehand.

4. Nov 6, 2012

### dazzler77

Thanks for the replies.
The website http://calculuslab.deltacollege.edu/...1/7-A-1-h.html was very helpful.

However I would like to have it start off horizontal rather than hanging, and curve around and be clamped below horizontal as well, like a "C" shape.

maybe in some ways it's more like compression than hanging.

5. Nov 7, 2012

### Simon Bridge

Well yes - cables don't generally hang like that... except if they are very stiff indeed. The approach is the same - the "C" would sag a little depending on the stiffness.