1) During cornering the wheel is subjected to a bending moment. When an overloaded vehicle takes a sharp turn at very high speed, this may cause excessive fatigue.
2)CFT is basically to simulate the condition mentioned at point 1.
3)This mainly causes stresses in the rim /disc joint area...
Yes, crack at vent holes is one of the very common "Failure patterns" observed during the cornering fatigue testing of wheel rims. It seems that in this particular case the failure has occured due to overloading. The fatigue life can be improved by changing the shape / size of vent...
