Progress in Fracture Mechanics in the United States of America

Abstract

This chapter discusses the progress in fracture mechanics in the United States of America. Fracture mechanics in the United States has been recognized as a technology that provides the unifying factor in mechanical failure prediction. Many of the U.S. industries are at present using fracture mechanics in design and to control structure integrity. The aircraft and nuclear-reactor industries have established nondestructive testing procedures for evaluating the criticality of flaws. Current activities in this area are to extend its application to materials with lower strength and structures with lower constraint so that the event of rapid crack growth will not occur suddenly or unexpectedly but be preceded by slow crack growth that hopefully can be detected. The insistence on the single-parameter approach has hampered progress on fracture mechanics research in the United States and will continue, if not corrected. Such a trend can have a far-reaching consequence on future fracture-related incidents that translate into a drain on the U.S. economy. In a free enterprise and profit-motivated system, technological advancement tends to outweigh basic research in support of understanding the technology. Major sectors of the U.S. industry have long discontinued fracture-related research and are at present at a loss in regard to the safety and life expectancy of their equipments. At present, there is a great demand in the US to develop step-by-step procedures that will involve the initial design, selection of materials and extend through all subsequent phases of production, that is, material specification, fabrication, inspection, proof testing and field service performance.