A theoretical approach for evaluating the plane strain fracture toughness of ductile metals

Fracture Mechanics of Ductile Metals (FMDM) theory is used to obtain the plane strain fracture toughness, K_lc, for different materials. The traditional approach for obtaining the K_lc value is to conduct several standard tests on cracked plates that are costly and time consuming. The fracture toughness value provided by the FMDM theory depends on the stress-strain curve for the material in question, and this is readily available in MIL-HDBK-5 and other reliable sources. The results of the plane strain fracture toughness (K_lc) values provided by the FMDM theory were compared with the experimental data and it was concluded that the two are in excellent agreement. It is proposed that, in the interest of economy and convenience, K_lc testing could be replaced by the FMDM theory.