This paper presents results of air-coupled ultrasound imaging performed on wood, fiber-reinforced plastics, "smart" structures, and fiber-reinforced ceramics (e.g. C/C-SiC) revealing delaminations, impacts, and growth of internal defects. 2001 American Institute of Physics.Stoessel...
We experimentally demonstrate and theoretically analyze high Q-factor (~107) capillary-based optical ring resonators for non-contact detection of air-coupled ultrasound. Noise equivalent pressures in air as low as 215 mPa/√Hz and 41 mPa/√Hz at 50
The falling cost of embedded sensor systems has opened up the possibility of in-transit air-coupled ultrasound interior imaging of shipping container cargo. This new technology could allow for real-time cargo integrity verification and improved shipping and transportation security. This paper takes the...
In the case of non-linear air-coupled ultrasound, the sample is excited at frequencies that have the centre frequency of the air-coupled narrow band receiver as an overtone. When the receiver scans across the sample, it responds selectively to the higher harmonics.In this study, high ...
or otherwise be destroyed. Additionally, air-coupled ultrasound offers the benefit of low, highly penetrating frequency ultrasound combined with the short wavelength in air. This allows the nondestructive inspection of previously untestable composits like thick, multilayer honeycombs, foam cores or green...
Digital Signal Processing Approach in Air Coupled Ultrasound Time Domain Beamforming 来自 国家科技图书文献中心 喜欢 0 阅读量: 36 作者:K Herman,T Gudra,J Furmankiewicz 摘要: The work presents the results of experimental study on the possibilities of determining the source of an ultrasonic signal ...
Passive focusing devices for Air-Coupled Ultrasound (ACU) transducers provide simple methods to concentrate the sound beam into a focus. This helps to improve lateral resolution and increase sensitivity. This work analyzed both theoretical and experimentally the behavior of three passive focusing devices...
aIt is therefore apparent that minimization of loss at every stage is key to achieving an acceptable signal to noise ratio for the inspection if air-coupled ultrasound is the chosen method of inspection 因此它是明显的损失的低估在每个阶段是关键的到达到一个可接受的针对噪音的信号比率为检查,如果空气...
These resonances appear at ultrasonic frequencies and have been excited and sensed using air-coupled ultrasounds. In spite of the complex leaf microstructure, the effective medium approach can be applied to solve the inverse problem, at least in the vicinity of the first thickness resonance. ...
using air-coupled, wide frequency band ultrasound and analysis in the frequency domain is presented. The working frequency range is 0.6-2.2 MHz. At normal ... TE Gomez,B Gonzalez,F Montero - Ultrasonics Symposium 被引量: 27发表: 2002年 Ultrasonic imaging of solid surfaces using a focussed ai...