L51413 Study of the Effect of Residual Stress on Fracture Behavior

This project has studied the generation of residual stresses in a stress free bar by a variety of means including mechanical loading and thermal means. The stress distributions generated have been compared to theoretical analyses and found to compare very well. The use of a mechanical loading system can produce a complex stress system up to a maximum of half the yield stress. Non-uniform cooling produces a simpler stress distribution with a maximum tensile stress in the center of the bar up to the yield stress. The work covered the modeling of stress distributions under varying conditions and the evaluation of toughness in the presence of residual stress.