Putting Generalized Fracture Mechanics to Work

A third point is that we can separate the surface and bulk contributions to the failure energy by taking logarithms  

In some circumstances, parallel curves are not obtained in such plots. This occurs when 1 becomes strain dependent and typically happens near the glass transition(9) or as loads become large. It can also happen if the volume of deformed material changes significantly from one test to another, as when peel testing is carried out at very low angles of peel. Although the 

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