CTOD or COD

"Borra" wrote .

Perhaps you could look for books related to fracture mechanics. I remember these are parameters being measured in some experimental fracture mechanics techniques.

John

could you please suggest me something to work on this area. i want to do some research work in fracture mechanics and in that CTOD. thanks

"Borra" wrote .

It was more than 30 years ago that I came across COD and CTOD, and I am by now retired. I faintly remember that measuring COD is not as good as CTOD for ductile materials as the plastic yield zone is around the crack tip.

The material with the crack is placed under increasing tensile load opening the crack. They insert a clever little devise (like a tiny screwdriver) deep into tip of the crack and measure how much this devise can rotate to see what is the crack tip displacement. I think at a certain threshold displacement the crack would propagate (or something like that).

As I said, this was more than 30 years ago, and I am sure there should be a lot more research and advances on this.

Anyway, nowadays (unlike the slow moving old days), the quickest way to find out more is through a Google search,

Just now I have just typed in CTOD and have got many hits with useful write-ups, including the theory and the relation of CTOD with fracture toughness.

John