# Optimization of fencing wire

1. Jan 13, 2012

### joebokl

hi all,

I would like to be regarded as a novice on the subject matter. I am doing a research on optimization of animal fence wire.

the idea basically is that, i want to improve on the existing design of wire used for animal fencing to minimize the chances of animals breaking out of fence. A cost effective solution is what I'm looking at.

I welcome all contributions.

Thank you

2. Jan 13, 2012

### joebokl

It's for livestocks fencing please

3. Jan 13, 2012

### meldraft

I'm not sure what you're looking for... If this is a design question, keep in mind that there is a thread for this sort of thing where you may get more answers than in the physics thread :)

https://www.physicsforums.com/forumdisplay.php?f=99 [Broken]

Last edited by a moderator: May 5, 2017
4. Jan 13, 2012

### Staff: Mentor

What is the context of the question? Is this for a school project? If so, at what level?

5. Jan 13, 2012

### mikeph

cost effective? Thick coil of barbed wire held down by tent pegs every 30m. Then cross your fingers the animals you're containing are not showjumping horses.

6. Jan 13, 2012

### joebokl

Yes, it's a level 3 school project.

7. Jan 13, 2012

### meldraft

Ok, you have the following design goals:

1. Use as less material as possible
2. Make the gaps small enough so that animals can't fit their claws/paws/mouths to break them
3. The stiffness of your structure is sufficient so that animals can neither permanently deform the wire, nor break the connections between the wires. This is influenced by:
3.a Wire thickness
3.b The shape of the holes
3.c The actual size of the fence and the moments/lever arms expected during interaction with animals
3.d The way the wires are connected to each other.

Out of all these, three parameters make up the cost:

1. Wire thickness along with total wire length make up the total material used (assuming everything else is the same for every design). The less material for the same job, the less the cost
2. Complexity of the design. This has to do with how sophisticated equipment or how many manhours you need to make the fence. This can be even more important than saving material.
3. How many of the fences you are planning to produce. The more you make, the lower the cost per fence. This is usually the most important out of the three.

8. Jan 16, 2012

### joebokl

thank you for your contribution. but the focus of the project is solely on the wire and not really on the fence. I'm looking at using heat treatment to improve the property of the wire and probably use an high tensile wire. Another idea i'm looking at is combining two wires of different properties to complement for the brittleness of the HT wire.
I'm still at the stage of developing the idea/method i can use to improve the wire.

what do you think?

9. Jan 16, 2012

### meldraft

Well, for starters, I am not sure what sort of answer you are looking for. If you just want to talk about the wire, then you can open a materials database and find a stronger material, or, even simpler, choose a thicker wire. Just make an estimation of the force required to break it, and select a material and cross section that give you, let's say, twice the tensile stiffness. Using two wires will probably up the cost though.

In case you are looking for something more complicated, here's some things that may help you out:

Is this meant for one fence, or is the project about a potentially mass-produced product? This is important for your cost.

In theory there are a lot of combinations that could give you the desired result, but you need to build an argumentation when you suggest a solution.

You have 1 objective and 1 constraint:

Fence is strong enough (<---- Constraint, this must always be satisfied)
Minimal Cost (<----- Objective)

Think simple. The above means that out of many possible solutions that satisfy the constraint, you want the most cost effective one.

My knowledge as far as fences are concerned is not much, so I can't really tell you what to do, but I can tell you what you need:

1. Mechanical calculations. Every solution that you suggest must have a background of calculations that prove or indicate that it will work as desired.

One thing that will really help you is to identify the factors that make existing fences break. Is it just the tensile strength of the wire? From experience, this has to do with the stiffness of the entire structure, so if you change the weaving (e.g. make the holes smaller) you can reduce the moments generated. Also, as I pointed out before, the way they are connected is also important.

2. Information about the cost determining factors. This will allow you to shape arguments on whether the solution you found is cost effective or not.

Examples of this would be the cost of acquiring machinery, the cost of electricity, man-hours, material costs (in case of a thicker wire, or a different material) and so on.

10. Jan 16, 2012

### joebokl

thanks for this. i'll use this as a starting point. i would always be coming here for further support. thank you once again