Toughness arrest

L. Dahlberg, F. Nilsson, and B. Brickstad, Influence of Specimen Geometry on Crack Propagation and Arrest Toughness, in Crack Arrest Methodologies... 

Fig. 10 a and b. Fracture toughness versus rate (a) and temperature (b) showing typical thermoset fracture behavior. I = initiation A = arrest E = stable crack growth... 

Fig. 12. Stoichiometric DGEBA/DDS network fracture toughness versus temperature. Fracture toughness from double torsion specimen at crosshead rate of 0.05 cm/min. Network T, s shown by dashed lines. O Initiation Arrest 9 Stable crack growth. (After LeMay...

The temperature dependence of the fracture toughness for the DGEBA/DDS networks is shown in Fig. 12. Crack growth initiation data are symbolized by the open circles, arrest data by the closed circles, and stable data by the half-filled circles. With the exception of the 1007F/DDS network, the initiation fracture toughnesses increase with the test temperature. In contrast, the arrest values exhibit no noticeable temperature sensitivity, and when observed, the stable fracture toughnesses are of the same magnitude as the arrest values. It is... 

Rapid crack propagation, dynamic fracture toughness, crack arrest, polyethylene pipes, pressure vessels... 

Key questions addressed by the efforts of the 1970s were whether the relationship between crack tip stress intensity and crack velocity was independent of specimen geometry, and whether crack arrest toughness could be assessed with a static analysis. 

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