Laser Shearography designed for strain analysis and inspection
Desser Tire and Rubber Company, LLC, and the repair station affiliate, Aero wheels and brakes Services Corporation uses state of the art laser interferometry Shearography testing for non-destructive testing of advanced aircraft and motorcycle tires carcass.
Although the principles of NDT measurements are not required by the FAA or the DOT, we feel the system significantly contributes to the safety features and the quality of our aircraft tire retreading. Michelin and Goodyear aircraft tire retreading division using the same method for testing the turboprop and jet transport heavy tires.
As a matter of fact .... our motorcycle tires can be tested more thoroughly than new tires. Because most of the new tires are not worn Laser Shearography, we can find areas of concern that have not been sought by the original manufacturer.
Shearography Measuring System
Shearography was originally designed for strain analysis and inspection and evaluation of honeycomb and composite bonded. Laser Shearography very sensitive to small changes in the surface strain due to subsurface flaws, and it is able to detect imperfections and defects such as belt-edge separation, abrasions beads, undercure, separation vessels and damaged wiring and construction ply aircraft tires.
Our new system accommodate aircraft tires to 49 "in diameter, combining the latest computer imaging analysis software, method-Shearing Interferometry Phase-electronics, integrated CCD camera laser diode, optical image analysis and adjusted the lighting in real time. System will store the test recorded on the disc for accurate tracking with work orders and serial number.
The benefits of this system are:
1 Dramatically improve the detection of abnormalities carcass
2 Immediately carcass fatigue detection
Immediately 3 internal damage detection carcass
Validation of 4 used 100% of the carcass
5. Improved detection of carcass damage
Desser Tire and Rubber Company, LLC, is the only aircraft tire retreader (including OEM) that has taken this action to support the safety and reliability of aircraft tire retreading our products for our customers. We will continue to look for ways to improve the quality and process of the products we provide. We look forward to supporting the needs of corporate and commuter aircraft operators around the world.
Here are the technical aspects of laser shearography:
Basics of interferometry
The following is a Non Destructive Testing methods are usually used for the examination of new tires and casings for retreading:
Ultra Sonics - low resolution
X-Ray - Other anomalies
Interferometry - interferometry is the core technology in our application and therefore is expressed in more detail now
In the past:
Holographic interferometry and the film based Shearography
Film-less "Speckle-interferometry" and "Speckle-Shearing"
- Compact optical setup sealed with
- Integrated interferometer with a CCD-camera
- Integrated laser diode laser
- Standard PC with image analysis system
Principles of Measurement
basic effect is the interference of light waves
- Fast and sensitive (~ 0.0004 mm periphery to periphery)
- Safe, no radiation (laser machine setup is class1) to get the effect of this interference light source must meet the following main requirements:
- A single frequency and constant over time (coherent)
measurement technique is based on:
- Michelson Interferometer for Shearing-Setup
- Phase-Shifting Method for the Analysis of Classic Picture
- Some Laser-Diode
(US Patent, No. 6,417,916 B1 US)
- Setup of measurement is positioned relative to the inner tube or / and outside
- Examination of the tire in the rim
- The whole setup is in the room to emphasize the difference in tire pressure
surface is illuminated with coherent light and simultaneously observe the sliding setup
two phase shifted images
- Before and after the stress load - which is superposed and preprocessed
SDS Systemtechnik GmbH Courtesy of.
Aero Wheel & Brake Service Corporation
6900 Acco Street, Montebello, CA 90640