THE UNITED STATES OF AMERICA AS REPRESENTED BY THE ADMINISTRATOR OF THE NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
发明人:
YOST WILLIAM T.,CANTRELL, JR. JOHN H.
申请号：
US20020263292
公开号：
US6584848(B1)
申请日:
2002.09.30
申请国别(地区):
美国
年份:
2003
代理人:
摘要：
An acoustic nonlinearity parameter (beta) measurement method and system for Non-Destructive Evaluation (NDE) of materials and structural members novelly employs a loosely mounted dielectric electrostatic ultrasonic transducer (DEUT) to receive and convert ultrasonic energy into an electrical signal which can be analyzed to determine the beta of the test material. The dielectric material is ferroelectric with a high dielectric constant is in. A computer-controlled measurement system coupled to the DEUT contains an excitation signal generator section and a measurement and analysis section. As a result, the DEUT measures the absolute particle displacement amplitudes in test material, leading to derivation of the nonlinearity parameter (beta) without the costly, low field reliability methods of the prior art.
