Hi all I was wondering if someone could help explain what the area under a load vs deflection curve tells you. I have a concrete sample which I loaded until it failed. I plotted the load (kN) and deflection (mm) as shown below. My question is; if the curve in red can be represented as a function f(x) (which I can do via regression) and I integrated this function from 0 to 0.75 (0.75 was the deflection at failure) then what does this tell me? What does the area under the curve tell you? From my research the area under a load vs deflection curve is meant to represent energy absorption but others have said it actually represents Work done? I was wondering if someone could explain? Thank you.