EVALUATION METHOD OF INDENTATION FRACTURE TOUGHNESS IN BRITTLE MATERIALS BASED ON FEA SOLUTIONS

摘要

The purpose of the present invention is to provide a method for evaluating the indentation fracture toughness of brittle materials based on finite element analysis (FEA) solutions, which is capable of evaluating the indentation fracture toughness of brittle materials based on indentation crack characteristics observed with a crack analysis applied with a cohesive zone model (CZM). To achieve this, the method for evaluating the indentation fracture toughness of brittle materials based on FEA solutions comprises the steps of: presenting standards defining the well-developed crack of a material; selecting strain _o, a Poissons ratio , and a Youngs modulus E absolute value as indentation variables affecting the size of a crack in the material, and presenting an indentation fracture toughness formula using the regression relationship among the _o, the v and, E_R (=E/E_1000) and K_o (=P_max/c^3/2); excluding the influence of the Youngs modulus using an indentation contact length a of the material, and presenting a fracture toughness formula using the relationship among the _o, the v and k(=P_max/c^ia^1.5-i); and presenting a regression function using E/H, a ratio of the Youngs modulus E to hardness H, and the Poissons ratio in order to obtain the _o.