| 摘要 |
<p>An acoustic nonlinearity parameter (ß) measurement method and system for Non-Destructive Evaluation (NDE) of materials and structural members novelly employs a loosely mounted dielectric electrostatic ultrasonic transducer DEUT(116)) to receive and convert ultrasonic energy into an electrical signal which can be analyzed to determine the ß of the test material. The dielectric material is ferroelectric with a high dielectric constant ∈. A computer-controlled measurement system coupled to the DEUT(116) contains an excitation signal generator section and a measurement and analysis section. As a result, the DEUT(116) measures the absolute particle displacement amplitudes in test material, leading to derivation of the nonlinearity parameter (ß) without the costly, low field reliability methods of the prior art.</p> |
