Modeling and Simulating Ultrasonic Wave Propagation in Layered Structures

摘要

Launch vehicles and spacecraft have many bonded layered structures, such as thepropellant insulation case assembly in solid rocket motors, multilayered printed circuit boards or solar array composite panels in satellites. NonDestructive Evaluation (NDE) techniques are used to ensure bond integrity as part of standard quality assurance programs and/or to restore confidence when an unusual event occurs that may have compromised the hardware. Ultrasonic techniques are among the most common and powerful NDE techniques used to probe bond integrity; however, beyond a single layer, the signals can become very complex. This signal complexity often makes it difficult to determine inspection feasibility without performing expensive and time consuming tests on representative hardware samples with simulated flaws. Under the NDE MOIE program, a powerful, flexible, and user friendly modeling program was developed using LabView TM to: (1) simulate the propagation of ultrasonic waves through multilayered structures, and (2) generate the oscilloscope signals one would expect to observe. In this report, the modeling program is described in detail, and sample results from a program simulation are compared with those of an associated experiment. The program's use of LabView TM's virtual instrument structure eases program modification update and provides instant cross-platform compatibility. This simulation capability has already been utilized to support a number of programs, including Titan, Milstar and special programs.