In: Mechanical Engineering
Define fatigue. Mention some of the important parameters by which fluctuating stress cycles are characterized.?
Fatigue is defined as weakening of material caused by repeatedly applied loads. Whenever a fluctuating load is applied on a material then the material fails before reaching the actual failure stress, this phenomenon is known as fatigue failure and it is very important in designing of materials under dynamic loading conditions. Fluctuating load means the load which is not static means either the load magnitude or direction or both is changing with time.
Fluctuating stress cycles are characterized by following parameters-
1. Mean variable load
2. Maximum amplitude of variable load
3. Direction of load
4. Number of cycles of load per minute or load frequency
5. Type of stress cycle whether fluctuating or repeated or completely reversed.