The J-Integral as a Fracture Parameter

J_Ic and J - Da curves

• relationship between J and Da, ductile crack length extension, was hypothesized.

• also proposed a physical ductile tearing process during different stages of fracture.

• J was only used to specify the onset of ductile tearing, point 3 in the figure.

• this point was defined as J_Ic, the critical J in mode I at the onset of ductile tearing.