Elements of Machine Design ME5I 22564 EMD

1. 22565 EMD : 1.6 : Fundamental of Design
Concept of Fatigue
Completely Reversed or Cyclic Stresses

2. 22565 EMD : 1.6 : Fundamental of Design
Fatigue :
Definition : When a material is subjected to repeated
stresses, it fails at stresses below the yield point stresses.
Such type of failure of a material is known as fatigue.
Endurance Strength :
Definition : It is defined as
maximum value of the
completely reversed
bending stress which a
polished standard specimen
can withstand without
failure, for infinite number
of cycles

3. 22565 EMD : 1.6 : Fundamental of Design
Creep :
Definition : When a part is subjected to a constant stress
at high temperature for a long period of time, it will
undergo a slow and permanent deformation called creep.