27 Questions
What type of stress is experienced by components subjected to dynamic loads?
Cyclic stress
Which test provides useful values for material selection and component dimensioning for statically loaded components?
Tensile test
What type of failure is caused by the applied load on the material in service application?
Permanent deformation failure
What type of stress changes constantly in components subjected to dynamic loads?
Cyclic stress
What properties are obtained from the fatigue test result?
S–N Curve
What is the phenomenon known as when a material fails due to repeated loading and unloading, even at low loads?
Fatigue failure
Under what conditions does fatigue failure typically occur?
After a lengthy period of repeated stress or strain cycling
What type of stress is necessary for fatigue to occur in a material?
Tensile stress
In which components/structures is fatigue failure a common phenomenon?
Bridges, cars, and airplanes
What is the nature of fatigue failure in normally ductile metals?
It results in no gross plastic deformation associated with failure
What type of cycle has symmetrical amplitude about a mean zero stress level?
Reversed (pure alternating) stress cycle
What does the repeated (alternating) stress cycle involve?
Asymmetric maximum and minimum stresses
In which type of stress cycle do the maximum and minimum stresses have equal magnitude?
Reversed (pure alternating) stress cycle
Which of the following is a distinguishing feature of dynamic loads as compared to static loads?
Dynamic loads cause the stress intensity to change constantly and the direction of the stress to vary.
In which type of fatigue tests does the stress intensity change constantly and the direction of the stress vary?
Cyclic tests
What is the primary focus of fatigue life improvement techniques?
To extend the duration before fatigue failure occurs in a material under dynamic loading
Which type of failure mechanism is commonly associated with components subjected to dynamic loads?
Fatigue failure
What type of stresses are necessary for fatigue life improvement techniques to be most relevant?
Cyclic stresses
What distinguishes fatigue failure from failure in application due to permanent deformation?
Fatigue failure involves cyclic stresses, while permanent deformation involves constant stresses.
What type of stress is necessary for fatigue to occur in a material?
Tensile stress only
What is the nature of fatigue failure in normally ductile metals?
Brittle-like with very little gross plastic deformation
Under what conditions does fatigue failure typically occur?
After a lengthy period of repeated stress or strain cycling
What type of failure is caused by the applied load on the material in service application?
Fatigue failure
What properties are obtained from the fatigue test result?
Fatigue strength and fatigue life
In which type of stress cycle do the maximum and minimum stresses have equal magnitude?
Reversed (pure alternating) stress cycle only
What does the repeated (alternating) stress cycle involve?
Asymmetric maximum and minimum stresses
What type of stress changes constantly in components subjected to dynamic loads?
Fluctuating stress
Test your knowledge of fatigue failure and design against fatigue in mechanical engineering with this quiz covering topics such as cyclic stresses, fatigue failure criteria, factors affecting fatigue properties, and fatigue life improvement techniques. Prepared by Dr. Reham Reda Abbas.
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