System and method of determining porosity in composite materials using ultrasound
US6684701B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 13, 2001 |
| Grant date | Feb 3, 2004 |
| Priority date | — |
| Expiry date | Jul 13, 2021 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2291/044
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The invention provides for ultrasonically measuring the porosity in a sample composite material by accessing only one side of the sample composite material and includes the steps of measuring a sample ultrasonic signal from the sample composite material, normalizing the sample ultrasonic signal relative to the surface echo of the sample composite material, and isolating a sample back-wall echo signal from the sample ultrasonic signal. A sample frequency spectrum of the sample back-wall ultrasonic signal is then determined. Next, the method and system include the steps of measuring a reference ultrasonic signal from a reference composite material, normalizing the reference ultrasonic signal relative to the surface echo of the reference composite material; and isolating a reference back-wall echo signal from the sample ultrasonic signal. A reference frequency spectrum of the reference back-wall ultrasonic signal is then determined. The invention further includes deriving the ultrasonic attenuation of the sample ultrasonic signal as the ratio of the sample frequency spectrum to the reference frequency spectrum over a predetermined frequency range. Comparing the derived ultrasonic atte…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.