Ultrasonic NDE of Bonds in Multilayered Systems.
NAVAL SURFACE WEAPONS CENTER SILVER SPRING MD
Pagination or Media Count:
Presented here is a report on a program to develop a procedure to use ultrasonics to nondestructively detect flaws in the bonding of layered materials. The program was begun by the Materials Evaluation Branch in 1981, and up to the present time the work has been done primarily through contracts with Tetra Tech, Inc., of Arlington, Virginia. The first contract period involved the development of a computer model utilizing normal-incidence beams, the design of the experiments to test the model, the performance of the experiments in collaboration with personnel at NSWC, and the analysis of the experimental results. At the end of the first contract period Tetra Tech recommended that angled beams be used rather than the normal-incidence beams that had been used, and this was done in the second year. The computer model developed under the first contract was modified to be used with angled beams. Experiments performed at 5 MHz with a bronze-epoxy-aluminum structure gave results consistent with the computer model relative to transit times, but questions exist relative to the models determination of reflection coefficients at the structures interfaces. Experiments performed at 1 MHz with a simulated bronze-epoxy-rubber-epoxy-bronze structure showed observable signals due to disbonds from as deep into the structure as the bottom side of the rubber plate.
- Test Facilities, Equipment and Methods