Drive shaft failed during service
Drive shaft failed during service
(OP)
Hi
One of our drive shaft is failed during service at the area where splines are located. the material is nickel alloy. The fracture surface is oriented at 45 degrees. the chemical and mechanical properties are perfect. some ratchet marks were also observed at spline root while at one location at spline root crack was also observed. Deformation marks were also observed at the spline where fracture has occured by looking at the fracture orientation can we say that the fracture is torsional overlaod failure with fatigue crack initiation? i have uploaded the side view of the shaft. Kindly provide your feedback.
One of our drive shaft is failed during service at the area where splines are located. the material is nickel alloy. The fracture surface is oriented at 45 degrees. the chemical and mechanical properties are perfect. some ratchet marks were also observed at spline root while at one location at spline root crack was also observed. Deformation marks were also observed at the spline where fracture has occured by looking at the fracture orientation can we say that the fracture is torsional overlaod failure with fatigue crack initiation? i have uploaded the side view of the shaft. Kindly provide your feedback.





RE: Drive shaft failed during service
RE: Drive shaft failed during service
Well to see whether its a fatigue failure we need to see the fracture surface at 90 degrees the the picture you have posted but yes it looks like torsional fatigue from your description and the 45 degree fracture line shows it failed along the principle stress planes.
This site might help:-
http://www.maintenancetechnology.com/2012/07/failu...
“Do not worry about your problems with mathematics, I assure you mine are far greater.” Albert Einstein
RE: Drive shaft failed during service
assuming a very good fatigue strength of the material itself, I'd like to point to something that shows up in your picture:
The fracture imo initiated at a place where the counterpart (hub?) is not only able to move as such but to achieve a chafing or rubbing pattern. The root cause of the failure (crack initiation) seems to be wear, and the fatigue (if present) and final overload (of a reduced sectional area) are derived effects.
So, apart from a pic of the fracture surface, could you pls. show how the counterpart looks like? Furthermore, a check for spline-to-spline match and effectivity of the (if any) hub fixation would be of interest.
Regards
Roland Heilmann
Lpz FRG
RE: Drive shaft failed during service
RE: Drive shaft failed during service
RE: Drive shaft failed during service