Dear Sanjay,

the energy which is introduced in the material before fracture during a tensile test (i.e., the material resistance in energy temrs) is the area under the stress-strain curve.

However, if you are working in fracture mechanics, please, take into account that there is no a simple relation between such area and fracture resistance in the presence of cracks or notches. To my knowledge, the Strain Energy Density Approach (SED, linear-elastic) is the most comprehensive model to assess fracture conditions by using the area below the stress-strain curve. This being said, it also requires defining a control volume (where the SED must be measured) which depends on the material fracture thougness (among other material properties).

Dear Mr. Tak,

First of all, what do you mean with "fracture energy" in combination with stress-strain diagrams?

As I published in several of my research publications, this term is often misused and mixed-up in literatur.

Specifically, I can recommend authentic benchmarks, such as GF (specific fracture energy) from Hillerborg (1985).

But please keep in mind you need to record the full load displacement diagram (not strain!) in a steady-stable manner.

Only a few setups are able to get this done even for brittle materials.

Check out my research and feel free to come back to me.

Yours sincerely,

Dr. Martin Brandtner-Hafner