Different methodologies to obtain the fracture properties of metallic materials using pre-notched small punch test specimens

One important topic in the application of the Small Punch Test (SPT) is to analyze its viability for the determination of the fracture properties of a material. This article describes three different approaches using pre-notched SPT specimens (p-SPT): the first one is based on the concept of crack tip opening displacement (CTOD), the second is based on measuring the area under the load-displacement curve for different initial pre-notch lengths, and the third approach is based on the numerical simulation of the specimen p-SPT for the J-integral determination. To explore the feasibility of this miniature test for obtaining the fracture properties of steels the test values obtained by the different approaches are compared with results obtained from conventional compact specimens C(T). The results indicate that p-SPT specimens can be used, when there is not enough material for conducting conventional fracture test, as an alternative method to estimate a value of the fracture properties under low constraint conditions.