Normal, sheer, and strain in Spiral/Helical Rope under Axial Tension

[Jfries289]

I'm in grave need to be able to calculate normal and sheer stresses and strain on spiraled or woven structures in general, and specifically on ropes. I'm doing a comparison to the hierarchical microstructure of collagen for a biomechanics paper based around the micro and macro structure of biological systems in comparison to real world applications.

Being able to calculate ultimate tensile strength as a function of spiral/helical radius would be most useful.

 

[Jabberwocky]

Without knowing any better I'd say to get yourself some physical samples and do some testing in a lab. That combined with manufacturer's specifications for their products should give you at least a basic idea of your strengths.

I don't know that there's a simple equation relating tensile strength to radius - not like conductance or flow rates...

 

[adrianviorel]

I just think stress resistance is a constant of a given material.Therefore, if you are talking about shear stress, this depends, exclusively, on the material and section's value. The fact that different kinds of ropes, made of the same material, are cracking at different stress values is a result of already existing internal stresses, that are algebrically added to the external ones, and also of the frictions between different sections of the cable, that are, also, energyconsuming processes. Having in mind all these considerations, I would think that a series of mechanical tests will give you an idea on the dependancy of the stress value for each type of rope, with the section's value. It's just an opinion...