P.T.O
(b) What is S-N curve endurance limit? Explain how this can be used to estimate the life (6) of
components during the design.

PART C
7, Differentiate linear elastic and elasto plastic fracture mechanics. (6) 3)
(0) What is critical strain energy release rate? Explain. (6)
8. (8)
Discuss any one fracture testing method. (6)
9. (@)What are the parameters affect the creep phenomena? explain (6)
(b) Explain, Larson-Miller parameter for predicting rupture life of a component. (6)

Using the Larson—Miller data for the 5-590 alloy shown in Figure | , estimate its

rupture life of a component that is subjected to a stress of 300 MPa at 650°C.

25 30 35 40 45 so
a ek rem லை 5

1000

100

Stress (MPa)

10

12 16 20 24 28
103 7120 + 1021 (-1)

Fig. |