Question

A specimen of 4340 Steel Tempered at 425 C is being tested using a single edge notched tension configuration. The estimated Y parameter for the SENT is 2.5. If the specimen is loaded to 60% of the yield strength, what length of starter crack (inches) will cause the specimen to fail by fracture

Answer 1

length of starter crack = 1.056

Step-by-step explanation:

given data

temperature = 425 C

yield strength = 60%

Y parameter = 2.5

solution

we use here A 20 table so we get here value that is

Sy = 1360 MPa

Kic = 117.5 MPa
`√(m)`

so length of starter crack will be

a =
`(1)/(\pi ) ((Kic)/(Y* \sigma max))^2` .....................1

put here value and we will get

a =
`(1)/(\pi ) ((117.5)/(2.5* 0.6 * 1360))^2`

solve it we get

length of starter crack = 1.056