Question

In the construction of a large reactor pressure vessel, a new steel alloy with a plane strain fracture toughness of 55 MPa-m1/2 and a Y value of 1.0. An in-service stress level of 200 MPa has been calculated. What is the length of a surface crack (in mm) that will lead to fracture

Answer 1

`l=24mm`

Step-by-step explanation:

From the question we are told that:

Plane strain fracture toughness of
`T=55 MPa-m1/2`

Y value
`Y=1.0`

Stress level of
`\sigma =200 MPa`

Generally the equation for length of a surface crack is mathematically given by

`l=(1)/(\pi)((T)/(Y*\sigma))^2`

`l=(1)/(3.142)((55)/(1*200))^2`

`l=0.024m`

Therefore

in mm

`l=24mm`