“…They can be divided into groups: terms related to plastic strain energy, elastic strain energy, strain energy gradient, total strain energy, and specific energy. The terms related to plastic strain energy are plastic CTOD [67], plastic energy in the point used in PM [87,88], Kujawsky and Ellyin plastic energy [90,91], ∆W p [79,83,84], U pl [81], and Q [83]. All of these consider a threshold of the plastic energy that triggers the crack growth when surpassed.…”