@thecarpathian - What is shear wave interference?
G'day thecarpathian, it's been a while mate.
When I looked back again at Tom's (theaudiotweek) discussion on shear waves, one of the first things I discovered was that shear waves don't occur in liquids or gases. This lead me to consider that it may have some relation to young's modulus and friction?! Sometimes the obvious guess is correct.
A very simplistic answer to a query of the relationship between Young's Modulus and Shear Modulus I understood quickly:
Another way to define the concept of shear modulus is by the use of the word “friction”. The best example might be to consider a pair of sneakers that are either too tight or too stiff. They run up and down on the back of the heel, eventually leading to a shearing injury, which on skin is seen as a blister. The extent of the sheering and therefore the blistering may depend on how long the shoes are worn, the type of motion and some other relative factors. For instance, a person who is running on a hot, summer day may see a lot more friction damage than a person who is just walking on a spring day.
As air is not a conduit for shear waves, according to my readings, the interactions between a guitar string and air will not produce shear waves.
There will be an interaction with the primary wave, where the Young's modulus (elasticity of the string) of the string will deform and return to it's static form under tension, and sheer wave or sheer modulus will be internal and against the frame holding the string
My question @theaudiotweek is how does resurfacing the outside of the string alter in any meaningful way, the internal friction caused by the primary wave splintering off perpendicularly as sheer waves, within the string?