AIRCRAFT TIRE RETREADING AND REMANUFACTURING SERVICES
Aero Wheel and Brake Service Corporation uses state-of-the-art interferometric Laser Shearography non-destructive testing for its aircraft tire retreads.
Although this NDT measurement principle is not required by the FAA
or the DOT, such a system significantly contributes to the
safety and quality features of our retreaded aircraft tires. Michelin, Dunlop and Goodyear Aircraft retread tire divisions use this same method for
testing on heavy turboprop and jet transport tires.
Our retreaded tires are individually tested in all NDT disciplines. Even new tires are only sampled for Laser Shearography testing, but our intent is to look for areas of concern on every turboprop and jet transport tire that goes through our stringent processes. We take our quality processes to the most exacting standards to ensure the best quality and most demanding first rate product is received by our customers.
Shearography Measuring System
Shearography was originally designed for strain analysis and
inspection and evaluation of honeycomb and bonded composites. Laser
Shearography is very sensitive to slight changes in surface strain due
to subsurface flaws, and it is able to detect imperfections and defects
such as belt-edge separations, bead blisters, undercure, liner
separation and broken cord and ply construction in aircraft tires.
Our new system accommodates aircraft tires up to 49" in diameter,
incorporating the latest computer imaging analysis software, electronic
Phase-Shearing-Interferometry methods, integrated laser-diode CCD
camera, and adapted optic illumination image analysis in real time. The
system will store the recorded test on disc for accurate traceability by
work order and serial number.
The benefits of this system are:
1. Dramatically increased carcass abnormality detection
2. Immediate carcass fatigue detection
3. Immediate internal damage of carcass detection
4. 100% validation of used carcass
5. Increased detectability of carcass deterioration
Below is the technical aspect of laser shearography:
Basics of Interferometry
The following are Non Destructive Testing methods typically used for the inspection of new tires and casings for retreading:
Ultra Sonics - low resolution
X-Ray - other anomalies
Interferometry - interferometry is the core technology in our applications and therefore it is declared in more detail now
In the past:
Film-based Holographic Interferometry and Shearography
Film-less "Speckle-Interferometry" and "Speckle-Shearing"
- Compact sealed optical setup with an
- Integrated interferometer with CCD-camera
- Integrated laser laser diodes
- Standard PC with an image analysis system
Principle of Measurement
The basic effect is the interference of light waves
- Fast and sensitive (~ 0,0004 mm fringe to fringe)
- Safe, no radiation (machine setup is laser class1) to get this
interference effect the light source has to meet the following main
- Single frequency and constant over the time (coherent)
the measuring technique is based on:
- Michelson Interferometer for the Shearing-Setup
- Classic Phase-Shifting Method for Image Analysis
- Multiple Laser-Diodes
(US Patent, No. US 6,417,916 B1)
Test-Setup for tire testing:
- The measuring setup is positioned relative to the tire inside or/and outside
- The inspection of the tire is in sections of circumference
- The whole setup is within a chamber to stress the tire with a pressure differential
The surface is illuminated with coherent light and simultaneously observed with the shearing setup
Two phase shifted images
- Before and after stress load
- Are superposed and preprocessed
Courtesy of SDS Systemtechnik GmbH.
Desser Holdings, LLC is the exclusive distribution agent for Aero Wheel and Brake Service Corp, LLC., aircraft retreads. From general aviation, helicopter , turboprop and jet transport tires, we support the needs of MRO, Airlines and companies worldwide to supply the best retread products.
TECHNICAL DATA DOCS:
Air Agency Certificate
Repair Station Operations Specifications & Ratings
EASA Approval Letter
Drug/Alcohol Program Certificate
Wheel Scope Services