Section 11.1. Background of Stress Intensity Factors
The emergence of fracture mechanics as a tool for determining
failure loads in materials has come a long way from the early work of A.A.
Griffith who, in 1920 presented his treatise on the understanding of the fracture
mechanism of glass, "The Phenomena of Rupture and Flow in
Solids". Griffith's work was
itself building on the earlier work by C.E. Ingliss summarized in
"Stresses in a Plate due to the Presence of Cracks and Sharp Corners"
Many researchers followed and built on the original concepts,
with a notable leader at the Naval Research Laboratory, Dr. G. R. Irwin,
applying the concepts and improving the methodology from the energy based
approach of Griffith to the stress intensity approach we use today. The Navy had a vested interest in this
analysis technique to understand the fracture of steel ship plate material used
in the World War II Liberty ships.
The 1950s and 1960s definitized the methodology by the
standardization of some of the test methods and application techniques. What we now view in numerous handbooks as
lists of stress-intensity factors (SIF) have each been "hammered out"
by a succession of researchers to improve the accuracy and usefullness of the
SIFs. Most of the advances have been
under the guidance of one or more of the technical societies such as ASTM, ASM,