A.A. Griffith, also known as Alfred A. Griffith, was a notable figure in the field of engineering and materials science. He is best known for his contributions to the understanding of fracture mechanics, which studies how materials break under stress. His work laid the foundation for many modern engineering practices and safety standards. Griffith's most significant achievement is the Griffith criterion, a mathematical model that predicts the conditions under which cracks will propagate in materials. This criterion has been widely applied in various industries, including aerospace and civil engineering, to improve the durability and reliability of structures and components.