finding the load by working backwards
finding the load by working backwards
(OP)
Finding the load from a crack
Hello there, Could some one with a bit more experience guide me here, Is it possible to arrive at a figure for loading from a cracked part.
I have a poorly designed bracket , that has cracked, What I was thinking was if the crack was to to a shear failure , then this would be at 90 deg to the principle stress, would it be possible to work backwards to arrive at the load the material saw when it failed.
I could look at the crack and determine if it was a once only overload failure or a fatigue failure
Are there any methods that one can use , without resorting to strain guages etc
Stephen
Hello there, Could some one with a bit more experience guide me here, Is it possible to arrive at a figure for loading from a cracked part.
I have a poorly designed bracket , that has cracked, What I was thinking was if the crack was to to a shear failure , then this would be at 90 deg to the principle stress, would it be possible to work backwards to arrive at the load the material saw when it failed.
I could look at the crack and determine if it was a once only overload failure or a fatigue failure
Are there any methods that one can use , without resorting to strain guages etc
Stephen





RE: finding the load by working backwards
As far as distinguishing overstress vs. fatigue, the best way is to observe the crack plane with a microscope. The patterns are indicative of the crack propagation mechanism.
Regards,
Cory
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.
RE: finding the load by working backwards
I am un aware of how to get from the crack length to the toughness test .. I will have to do a bit of noseying around , the books I have arnt much help here ( Mechanical , by shigley )
Thanks it gives me something to think about
cheers Stephen
RE: finding the load by working backwards
Regards,
Cory
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.
RE: finding the load by working backwards
now you have done it an excuse to purchase another book ...she who must be obeyed will shoot me
Still its all in a good cause
Thanks so much for all the help , I did a bit of checking and came up the same ally as u suggested , So i will look into that book ( please let it be cheap at Amason!!!)
Kind Kind Regards
Stephen
RE: finding the load by working backwards
on the address below you'll find best price for any book.
http://www.bestwebbuys.com/books/
RE: finding the load by working backwards
Stephen