In characterizing the plain stress resistance, the concept of the essential fracture work (EWF) is applied for ductile polymers and associated structures. A basic specimen preparation, simple data reduction processes, and easy testing contribute to the comprehensive application of the EWF. This approach is the way of splitting the fracture-associated energy into two sections. In its internal fracture process, critical fracture works and various mechanisms consume plastic work in outward of the plastic region. The crucial function of crack propagation fractures is evaluated in the present geometry of the work test, namely the(DENT) and the SENT specimens. Where DENT is “double-edged notched tension” and SENT is “single-edged notched tension”. The novel approach is to measure the precise fracture work in profoundly double-edged samples as a function of ligament length. This sort of information is further checked empirically to eliminate the plastic fracture work and allows for the ligament-length function of the critical fracture. These claims are applied to assess the EWF by extrapolating critical fracture work to zero-ligament length.