Fatigue on 1100 Untempered Al? 1

[ajensen]

Hi All,

I have an application in which a piece of 1100 untempered Al us bent around a ~2" radius, and then re-formed back to its original flat shape (it starts as a flat sheet). The part is 2" wide x ~6" long x .040" thick, and is bent almost 180 deg around the aforementioned radius by hand. This happens a few times a day for as long as the Al lasts. I have searched for some type of empirical data or theoretical failure model to help me predict how long the part will last, but of yet have not found anything.

I've done some experimenting of my own and have gotten a part to last around 100 cycles, however my method was not very controlled. Does anyone have experience with something like this? Is there a mathematical model I can use to help predict (even ballpark) the point at which failure in fatigue will occur?

 

[TVP]

Are you familiar with the Goodman method for fatigue life estimation? Take a look through the resources here:

https://www.efatigue.com/

 

[metengr]

In reality, you have conducted your own strain-life rudimentary testing to determine the number of cycles to failure - similar to a paper clip fatigue experiment where you bend the paperclip x times until failure.

 

[ajensen]

TVP, thanks for the link. I will review the Goodman method.