fracture toughness

Question 1

what does fracture toughness measure

Answer 1

the ability of the material containing a flaw to withstand an applied load.

Question 2

three types of cracks in fracture toughness

Answer 2

edge crack
internal crack
elliptical crack

Question 3

stress intensity factor formula

Answer 3

K = Y x stress x square root of (pi a)
 - applied stress
a – flaw size
Y – geometrical factor, dependent on material and flaw geometry

Question 4

four factors that effect the material resistance to crack growth

Answer 4

large flaws that reduce the permitted stress
increasing the strength of a material will reduce the fracture toughness
thicker materials have lower stress intensity factor(K) than thin materials
increase of temp usually increases the fracture toughness of bcc and hcp material but fcc are relatively un effected by temp.