A nondestructive evaluation (NDE) technique for detecting incipient cracking was developed by monitoring the internal damping characteristics of a structure. The application is being applied to offshore structures as a means for locating joints which are fatiguing and for monitoring and predicting structural life without putting personnel into the water. The Office of Naval Research (ONR) Structures Program is funding a computer-assisted NDE adjunct to this program.
Complete. A four-legged, 14-foot high model offshore structure was built. The NDE technique was applied to the model and data was processed through a computer. Results on the model, in air, show that the technique revealed both incipient failures of joints and broken members. The technique was evaluated in an ONR-USGS program called the NDE Round Robin. See Project No. 34.