Interrelation between energy partitioned work of fracture parameters and the crack tip opening displacement in amorphous polyester films

The total work required to fracture a deeply double edge notched tensile (DDENT) specimen can be divided into the work required to yield the ligament region and the tearing energy for the necked ligament area up-to-fracture. Methods A and B require the same procedure and number of DDENT specimens for the critical crack tip opening displacement (CTOD) determination as the essential work of fracture (EWF) method does. The results achieved by Method B fit the experimental data well, while Method A overestimates the essential work of fracture and its yielding- and necking-related terms. The interrelation between CTOD and EWF terms provides useful information on the fracture mechanics of the material and validates the EWF fracture mechanical method.