IS THIS TRUE??

[robj144]

This can be calculated approximately instead of debating what is happening. From this source:

https://en.wikipedia.org/wiki/Yield_(engineering)

Typical yield strengths for metals are 100's of MPa. From this website:

http://www.daddario.com/DAstringtens...c-ceed0843739b

I calculated the stress on guitar strings. It ranges from about 10 MPa for the low E to 1000+ MPa for the high e. So, most likely, some or all of the strings are stretched beyond their yield and suffer plastic deformations. Hence, they stretch and their cross sectional area decreases. Since tension is

T = 4 A L^2 p f^2

where A = cross sectional area, L = length of vibrating string, p = mass density of string, f = frequency of string.

Hence, if tuned to the same frequency, with the same vibrating length, same mass density (same material for the string), if the area decreases over time due to the string stretching, the tension will decrease over time.

[Glennwillow]

It was good of Robj144 to actually run the numbers, above. His approach is pretty convincing.

- Glenn

PS: I hope Galileo is not too disappointed in the rest of us.

[rick-slo]

I have not found metal properties specific to guitar strings on line but it is probably the in the same range as piano string wire (and for the same reasons).

See: https://ef.engr.utk.edu/ef152-2015-0...in-elastic.pdf

The data on the above link would give for example an ultimate strength limit of 43.791 pounds of tension for a 0.013" guitar string. So for example tension wise on
a 25.5" scale guitar that is equivalent to the high E string tuned up to about G#, not that I would ever do that. For elastic limit, again no specific data for guitar
strings but using high strength steel as an example the elastic limit would be about 39 pounds (high E tuned up to about G).

[robj144]

Originally Posted by rick-slo

I have not found metal properties specific to guitar strings on line but it is probably the in the same range as piano string wire (and for the same reasons).

See: https://ef.engr.utk.edu/ef152-2015-0...in-elastic.pdf

The data on the above link would give for example an ultimate strength limit of 43.791 pounds of tension for a 0.013" guitar string. So for example tension wise on
a 25.5" scale guitar that is equivalent to the high E string tuned up to about G#, not that I would ever do that. For elastic limit, again no specific data for guitar
strings but using high strength steel as an example the elastic limit would be about 39 pounds (high E tuned up to about G).

Well most of a string is bronze and for bronze:

http://www.matweb.com/search/DataShe...47dbca4&ckck=1

Yield strength is 69.0 - 800 MPa with an average of 314 MPa. Acoustic strings are probably in that ballpark and several strings are around or above that yield strength when tuned.

[rick-slo]

Originally Posted by robj144

Well most of a string is bronze and for bronze:

http://www.matweb.com/search/DataShe...47dbca4&ckck=1

Yield strength is 69.0 - 800 MPa with an average of 314 MPa. Acoustic strings are probably in that ballpark and several strings are around or above that yield strength when tuned.

The windings are not the issue. The string core is.

[robj144]

Originally Posted by rick-slo

The windings are not the issue. The string core is.

That's correct. I forget that was the wrapping. The core is mostly high carbon steel:

https://www.azom.com/article.aspx?ArticleID=6575

Yield strength is about 500 MPa.

[rick-slo]

Originally Posted by robj144

That's correct. I forget that was the wrapping. The core is mostly high carbon steel:

https://www.azom.com/article.aspx?ArticleID=6575

Yield strength is about 500 MPa.

Nope, note that metal.

[robj144]

Originally Posted by rick-slo

Nope, note that metal.

https://reverb.com/news/guitar-strin...fits-explained

"At the core is a six-sided high-carbon steel wire, typically called core or music wire. Music wire is hexagonal, as the edges give the outer wrap wire something to grab."

[rick-slo]

Originally Posted by robj144

https://reverb.com/news/guitar-strin...fits-explained

"At the core is a six-sided high-carbon steel wire, typically called core or music wire. Music wire is hexagonal, as the edges give the outer wrap wire something to grab."

Nope. For example your proposed metal specs would have a 0.013" high E string snapping at 12.27lbs of tension ( 92100 psi X 0.0001327 sq in)

[robj144]

Originally Posted by rick-slo

Nope. For example your proposed metal specs would have a 0.013" high E string snapping at 12.27lbs of tension ( 92100 psi X 0.0001327 sq in)

Then what is it? That article states it's high carbon steel.

[robj144]

Did some more digging for high carbon steel:

http://www.matweb.com/search/DataShe...1ad67f8a83e858

Average ultimate strength is 1000 MPa which would give a breaking tension of about 18.0 lbs for 0.013" diameter. Average yield strength is 810 MPa. I would say that some strings deform, but we need more specific information and I don't know where to find it.

[rick-slo]

Originally Posted by robj144

Then what is it? That article states it's high carbon steel.

First see my prior link: https://ef.engr.utk.edu/ef152-2015-0...in-elastic.pdf

There are several different alloys of stainless steel and they vary widely in properties such as tensile and elastic limits. Exactly what is used for guitar
strings I don't know, but as I said prior it probably has properties similar to piano wire.

[robj144]

Originally Posted by rick-slo

First see my prior link: https://ef.engr.utk.edu/ef152-2015-0...in-elastic.pdf

There are several different alloys of stainless steel and they vary widely in properties such as tensile and elastic limits. Exactly what is used for guitar
strings I don't know, but as I said prior it probably has properties similar to piano wire.

It is... it's also high carbon steel:

http://optimumspring.com/technical_r...ring_wire.aspx

Here's more detailed info though:

http://www.matweb.com/search/datashe...4d9de31c2c6849

[zmf]

Originally Posted by rick-slo

See: https://ef.engr.utk.edu/ef152-2015-0...in-elastic.pdf

The data on the above link would give for example an ultimate strength limit of 43.791 pounds of tension for a 0.013" guitar string. So for example tension wise on
a 25.5" scale guitar that is equivalent to the high E string tuned up to about G#, not that I would ever do that. For elastic limit, again no specific data for guitar
strings but using high strength steel as an example the elastic limit would be about 39 pounds (high E tuned up to about G).

That's very useful information.

It would seem that if the "strength limit" is known, then using the Elasticity function you referred to, the amount of stretch below that limit could be estimated as a first approximation if a function were estimated back to zero tension -- if I'm interpreting this stuff correctly.

Might answer the question of whether the string stretches when tuned to pitch.

[robj144]

And here:

https://www.makeitfrom.com/material-...500-Music-Wire