Correlationship between JIC and equivalent fracture strain determined by small-punch tests in JN1, JJ1 and JK2 austenitic stainless steels

Polymer pre-notched small punch specimens to evaluate the essential work of fracture (EWF) parameters

“…In recent decades, a great number of researchers have used the SPT in order to obtain the mechanical and fracture properties of materials when there is not enough material for conducting standard tests [7][8][9], but very few researchers have utilized pre-notched SPT specimens [10,11]. The experimental setup can be consulted in the CEN code of practice for small punch testing [12].…”

Development of a new methodology for estimating the CTOD of structural steels using the small punch test

“…This consists of the measurement of the so-called biaxial strain at fracture, e qf , which relates the original specimen thickness, t, to the thickness measured in the failure zone, t f (expression 1). Several authors [2,5,9,[11][12][13][14] have found good relationships between this parameter and fracture toughness, although very different, totally empirical expressions have been obtained, showing a clear dependence on the type of material. Other reported strategies include the measurement of the energy furnished by the test until a 20% drop after the application of the maximum load [6,15] or the estimation of the parameters of an appropriate damage model by applying neural networks to the SPT result and subsequently simulating the mechanical behaviour of the standard fracture toughness test [16,17].…”

Application of the small punch test to determine the fracture toughness of metallic materials

“…Subsequently, several authors 9,11–14 have tried to obtain fracture parameters ( K Ic , fracture energy, damage parameters) using the same type of samples. However, although some promising results have been obtained, there is still no experimental procedure able to predict the fracture toughness of a ductile metallic material from the SPT 15–17 . Moreover, given that the fracture toughness is the energy required to initiate the growth of a pre‐existing crack, it would appear that a notched or cracked specimen is required to obtain an accurate enough result.…”