The samples were identical except for the properties of the joint. As shown in the figure, the defects in the joints were easily detected by all three methods. The effect of the defects on acoustic wave properties included a loss in amplitude and change in frequency content for propagating waves, a shift in resonance peaks, and a change in the amplitude response of the samples. Aluminum and steel specimens provided by the Ford Motor Company were evaluated using pulse transmission, global resonance, and local resonance techniques. As shown in the plots, defects in the joints were easily detected by all three methods.
Results shown are for steel samples.
The modeling results were used to provide guidance in the design of laboratory experiments, and to help in the interpretation of results from laboratory resonance experiments. Finite-element modeling of the test specimens provided by Ford was performed to guide laboratory experiment design and to help in the interpretation of experimental results. Epoxy joint with a three-inch gap with no adhesive. This effort generated significant interest. Next, based on project results presented to the Ford Motor Company in Detroit in February 1996, Ford actively supported LBNL efforts to obtain long-term DOE funding by securing the support of GM and Chrysler as required by DOE for proposals submitted under the auspices of the Partnership for New Generation Vehicles.