George Rankine Irwin

George Rankine Irwin (March 20, 1907 – February 9, 1998) was an American physicist known for his work on the mechanical behavior of solids and his contributions to the field of fracture mechanics.

Irwin developed the concept of stress intensity factor, which is widely used in fracture mechanics to determine the critical stress necessary for a crack to propagate. He also introduced the crack-opening displacement (COD) method for measuring the amount of crack propagation in materials.

The stress intensity factor is a measure of the stress field at the tip of a crack in a solid. It quantifies the level of stress concentration and is used to predict crack propagation and failure in materials. George R. Irwin developed this concept and it has become a fundamental tool in fracture mechanics.

The crack-opening displacement (COD) method, introduced by George R. Irwin, is a technique for measuring the amount of crack propagation in materials. It involves measuring the relative displacement of the crack surfaces as the crack grows under applied load. The COD method provides valuable data for analyzing the behavior of cracks in various materials.

In addition to his work in fracture mechanics, Irwin made significant contributions to the understanding of the mechanical behavior of solids. He developed a theory for the plastic deformation of metals, known as the strain-hardening theory, and derived equations to describe the relationship between stress, strain, and temperature in solid materials. His research has had a lasting impact on the field of materials science.