Design of Multi-Frequency Ultrasonic Pulse-Echo System

Near Real Time Ultrasonic Pulse Echo Holographic Imaging System

Frequency Effects in High-Frequency Pulse- Echo Ultrasonic Imaging of Titanium Metal Matrix Composites

Inspection of titanium matrix composites (TiMMCs) is required during manufacture, to ensure that defects are found before the material is incorporated into complex structures. The manufacturing process involves lay-up of fibres followed by Hot Isostatic Pressing. Individual fibres must remain in alignment and with precise separations in order to maintain the mechanical properties of the materia...

Behavioural Modelling and Simulation of a Mems-based Ultrasonic Pulse-echoo System Behavioural Modelling and Simulation of a Mems-based Ultrasonic Pulse-echo System

This paper describes the design, modelling and simulation of an acoustic microsystem in a pulse-echo ultrasonic application. The microsystem, used as emitter and receiver of ultrasonic signals, consists of a bulk micromachined suspended membrane. During emission, the membrane is placed in an oscillator loop and is thermally actuated at its resonance frequency (≈ 40 kHz). This frequency is sligh...

Ultrasonic Pulse-Echo Subwavelength Defect Detection Mechanism: Experiment and Simulation

The ultrasonic pulse-echo backscattered amplitude integral (BAI)-mode imaging technique [IEEE Trans. UFFC, 45:30 (1998)] has demonstrated sensitive detection of subwavelength channel defects (38m diameter reliably and 6m diameter occasionally) in flexible 220m-thick food package seals (17.3 MHz, 86 m). However, the underlying subwavelength defect detection mechanism is poorly understood. In thi...

Defect visualization of aircraft UHF antenna radome using full-field pulse-echo ultrasonic propagation imaging system

Most of aircraft antennas usually have various types of radome made of composite materials for protecting antenna structures. However, these antenna radome structures, which are installed on the outside of airplane, are easy to be damaged by external forces such as drag, foreign object, bird strike and others. In this study, full-field pulse-echo ultrasonic propagation imaging (PE UPI) system i...