Water and hydraulic oil intrusion inside honeycomb sandwich Structure Composite during service has been
linked to in-flight failure in some aircraft. There is an ongoing effort to develop nondestructive testing methods to detect
the presence of water and hydraulic oil within the sandwich panels. Pulsed thermography(PT) represents an attractive
approach in that it is sensitive to the change of thermal properties. Using a flash lamp PT, testing can be applied directly
to the surface of the panel. The viability of PT is demonstrated through laboratory imaging of both water and hydraulic
oil within sandwich panels. The detection of water and hydraulic oil intrusion using a one-sided flash lamp PT is
presented. It is shown that simple detection, as well as spatial localization of water and hydraulic oil within sandwich
panels, and assign the quantity of water and hydraulic oil is possible.
As the key parts of the liquid rocket oxyhydrogen engine, the injector panel is a kind of transpiration material, which is
braided and Sintered with stainless steel wire. If some hidden delaminition defects that are difficult to detect appear in
the process of Sintering and rolling, a significant safety problem would occur. In this paper, we use the Ultrasonic Burst
Phase Thermography (UBP) to detect the delamination defects in the injector panel, UBP is a rapid and reliable
nondestructive technique derived from Ultrasonic Lock-in Thermography(ULT). It uses a controllable, adjustable
ultrasonic burst as the heat source to stimulate the sample, the defects within the material are revealed through their heat
generation caused by friction, clapping and thermoelastic effect, as the resulting surface temperature distribution is
observed by an infrared camera. The original thermal images sequence is processed by Fast Fourier Transformation to
obtain the phase information of the defects. In the experiments of the delamination sample, the UBP realized the
selective heating of delamination defects in the injector panel, and the signal to noise of phase image is higher than the
original thermal image because the phase information can not be disturbed by the initial conditions (such as the reflective
surface of sample). However, the result of the detection of flat bottom hole transpiration panel sample reflects that UBP
is not appropriate for the detection of this kind of defects, because it is difficult to induce frictional heating of flat bottom
holes. As contrast, Flash Pulse Thermography is used to detect the flat bottom holes, all of the holes of different depth
and sizes can be seen distinctly. The results show that PT is more appropriate for the detection of flat bottom holes
defects than UBP, therefore, it is important to select the appropriate excitation method according to different defects.
A novel five transistor global shutter CMOS active pixel with ultra-high dynamic range is presented in this paper. A
global shutter control transistor is added to traditional four transistor pixel. The five transistor pixel image sensor works
in global shutter mode to shoot high speed moving object with dual sampling to eliminate fixed pattern noise. The image
sensor can restore four transistor pixel rolling shutter mode with global shutter control transistor shutoff to shoot
stationary object with correlated dual sampling to eliminate fixed pattern noise and random noise. A digital control
stepped reset-gate voltage technique with no additional components to increase dynamic range by the compression of
charge integration characteristic curve and to implement anti-blooming by discharging excess carriers is adopted.
Simulation results show that the image sensor can work in global shutter mode and the dynamic range is increased
approximately by 20dB than typical CMOS image sensor.
A novel APS pixel with full frame self-storage and motion detection capabilities is proposed in this paper. Taking
advantage of adding the independent exposure transistor, the FD node of traditional 4T pixel can be used for temporarily
storing the integrated charge between two successive frames. Before the current frame's reset operations, the charge of
previous frame will been readout and compared with the subsequent signal of current frame to locate the motion pixel in
the motion detection comparators which is integrally shared by columns and have a lower load capacitor and higher gain
than the previously published counterparts. The pixel and its peripheral circuit are designed and simulated using SMIC
0.18μm MM/RF 1P6M process. The simulation indicates that the image sensor using proposal design can achieve the
motion detection without obvious reduction of fill factor and have a higher accuracy of detection and lower power
consumption, which is more suitable to the application of surveillance and remote video communication network.
The rotor blades are key components in wind turbine generators. A visual inspection of the laminated shells for
delaminations, air pockets, missing/disoriented fabric etc. is in most cases also not possible due to the manufacturing
process, so Non-destructive testing and evaluation (NDT & E) techniques for assessing the integrity of rotor blades
structure are essential to both reduce manufacturing costs and out of service time of wind turbine generators due to
maintenance. Nowadays, Infrared Thermal Wave Nondestructive Testing (Pulsed thermography) is commonly used for
assessing composites. This research work utilizes Infrared Thermal Wave Nondestructive Testing system (EchoTherm,
Thermal Wave Imaging, Inc.) to inspect a specimen with embedded defects (i.e. foreign matter and air inclusions) in
different depth which is a part of rotor blades in wind turbine generators, we have successfully identified defects
including foreign matter and air inclusions, and discovered a defective workmanship. The system software allows us to
simultaneously view and analyze the results for an entire transition.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.