Many bridges constructed by steel plates welded together to form deep girders or large box sections have collapsed as a result of the brittle fracture fatigue failure of the weld metal. A technique to increase the fatigue life of welds would be very beneficial to local, state and Federal agencies who have the responsibility of constructing and maintaining bridges within their jurisdiction. This project will investigate an innovative technique of using an explosive treatment applied to the weld metal in order to improve its fatigue life. This technique has the potential of being an effective low cost method when compared with the currently applied alternatives. The research will consist of establishing the mechanism by which a shock wave enhances the failure resistance of weld metals. The researcher is qualified to perform this investigation from experience and education and the required experimental facilities are available. This is the first year of a two year award for an amount of $91,395 for the first year and $96,868 for the second year for a total of $188,263.
