In situ non-destructive evaluation of an aircraft UHF antenna radome based on pulse-echo ultrasonic propagation imaging

2017 ◽  
Vol 160 ◽  
pp. 16-22 ◽  
Author(s):  
Hye-Jin Shin ◽  
Jae-Yoon Park ◽  
Seung-Chan Hong ◽  
Jung-Ryul Lee
Keyword(s):  
Non Destructive Evaluation ◽  
Ultrasonic Propagation ◽  
Pulse Echo ◽  
Non Destructive ◽  
Uhf Antenna

Sizing Detection of a Surface-Breaking Crack by Ultrasonic Technique

2011 ◽  
Vol 52-54 ◽  
pp. 865-868 ◽  
Author(s):  
Shiuh Chuan Her ◽  
Sheng Tung Lin
Keyword(s):  
Test Specimen ◽  
Incident Angle ◽  
Ultrasonic Technique ◽  
Non Destructive Evaluation ◽  
Different Depths ◽  
Crack Sizing ◽  
Incident Waves ◽  
Surface Breaking Crack ◽  
Pulse Echo ◽  
Non Destructive

Ultrasonic is one of the most common uses of non-destructive evaluation technique. It could detect flaws inside the structure and on the surface such as voids, holes and cracks. In this investigation, a 304 steel block with a surface-breaking crack was fabricated. A series of test specimen with different depths of surface-breaking crack ranging from 2mm to 9mm was fabricated. The depth of the surface crack was evaluated by the pulse-echo ultrasonic technique. In this work, 2.25MHz, 5MHz and 10MHz of incident waves were employed to detect the depth of the surface-breaking crack. The effect of incident angle on the measuring accuracy was investigated. Experimental results showed that the accuracy of crack sizing detection by ultrasonic technique is not only dependent on the frequency of the incident wave but also dependent on the incident angle.

Non-Destructive Evaluation of Strains and Voiding in Passgvated Copper Metallizations

1993 ◽  
Vol 308 ◽  
Author(s):  
Richard P. Vinci ◽  
Thomas N. Marieb ◽  
John C. Bravman
Keyword(s):  
Thermal Cycle ◽  
Strain State ◽  
Hydrostatic Stress ◽  
Strain Analysis ◽  
X Ray ◽  
Non Destructive Evaluation ◽  
State Determination ◽  
Non Destructive ◽  
Voltage Scanning

ABSTRACTStress induced voiding in passivated Cu lines was investigated by x-ray strain analysis and in-situ high voltage scanning electron microscope (HVSEM) techniques. Cu lines on a Ta underlayer and Cu lines on an Al underlayer were patterned by a trilayer liftoff technique and passivated with Si3N4. For direct observation of stress voiding, specimens were heated to 350ºC in the HVSEM and then cooled and held at 150ºC. Identical samples were subjected to the same thermal cycle for strain state determination using x-ray techniques. The hydrostatic stress state at each temperature was calculated from the measured strains. Few initial voids were observed after passivation in either sample. After heating to 350ºC and cooling to the dwell temperature, no new voiding was seen in the Ta/Cu lines. Measured hydrostatic strains were half those measured in the Al/Cu lines. Heavy voiding was observed in the Al/Cu lines after cooling to the dwell temperature.

scholarly journals Implementation of Non-Destructive Evaluation and Process Monitoring in DLP-based Additive Manufacturing

2017 ◽  
Vol 7 (1) ◽  
pp. 100-105 ◽  
Author(s):  
Iaroslav Kovalenko ◽  
Sylvain Verron ◽  
Maryna Garan ◽  
Jiří Šafka ◽  
Michal Moučka
Keyword(s):  
Control System ◽  
Process Monitoring ◽  
Continuous Measurement ◽  
Adhesion Force ◽  
3D Printer ◽  
Digital Light Processing ◽  
Non Destructive Evaluation ◽  
The Moment ◽  
Non Destructive

AbstractThis article describes a method of in-situ process monitoring in the digital light processing (DLP) 3D printer. It is based on the continuous measurement of the adhesion force between printing surface and bottom of a liquid resin bath. This method is suitable only for the bottom-up DPL printers. Control system compares the force at the moment of unsticking of printed layer from the bottom of the tank, when it has the largest value in printing cycle, with theoretical value. Implementation of suggested algorithm can make detection of faults during the printing process possible.

Real world application of angular scan pulse-echo ultrasonic propagation imager for damage tolerance evaluation of full-scale composite fuselage

2019 ◽  
Vol 18 (5-6) ◽  
pp. 1943-1952 ◽  
Author(s):  
WJ Lee ◽  
BH Seo ◽  
SC Hong ◽  
MS Won ◽  
JR Lee
Keyword(s):  
Composite Structures ◽  
Fatigue Testing ◽  
Damage Tolerance ◽  
Structural Characteristics ◽  
Full Scale ◽  
Inspection Method ◽  
Complex Test ◽  
Ultrasonic Propagation ◽  
Pulse Echo

Composite structures are assertively used for new airframe designs and manufacturing in military aircrafts because of superior strength-to-weight ratios and fatigue resistance. Because the composites have different fatigue failure characteristics compared with metals, it is necessary to develop different approaches for the composite fatigue design and testing. In this study, we propose an in situ damage evaluation technology with high spatial resolution during full-scale fatigue testing of composite aircraft structures. For real composite structure development considering composite fatigue characteristics, full-scale fatigue and damage tolerance tests of the composite fuselage structure were conducted to evaluate the structural characteristics. In the meantime, the laser ultrasonic nondestructive inspection method, called an angular scan pulse-echo ultrasonic propagation imager, which is fully noncontact, real-time, and portable to position it in between the complex test rigs, is used to observe in situ damage growth of the composite. Finally, the verification procedure assisted by the angular scan pulse-echo ultrasonic propagation imager assures no growth of the initial impact damages after lifetime operation and proves the damage tolerance capability of the developed composite fuselage structure.

Non-Destructive Evaluation of Strains and Voiding in Passivated copper Metallizations

1993 ◽  
Vol 309 ◽  
Author(s):  
Richard P. Vinci ◽  
Thomas N. Marieb ◽  
John C. Bravman
Keyword(s):  
Thermal Cycle ◽  
Strain State ◽  
Hydrostatic Stress ◽  
Strain Analysis ◽  
X Ray ◽  
Non Destructive Evaluation ◽  
State Determination ◽  
Non Destructive ◽  
Voltage Scanning

AbstractStress induced voiding in passivated Cu lines was investigated by x-ray strain analysis and in-situ high voltage scanning electron microscope (HVSEM) techniques. Cu lines on a Ta underlayer and Cu lines on an Al underlayer were patterned by a trilayer liftoff technique and passivated with Si3N4. For direct observation of stress voiding, specimens were heated to 350°C in the HVSEM and then cooled and held at 150°C. Identical samples were subjected to the same thermal cycle for strain state determination using x-ray techniques. The hydrostatic stress state at each temperature was calculated from the measured strains. Few initial voids were observed after passivation in either sample. After heating to 350°C and cooling to the dwell temperature, no new voiding was seen in the Ta/Cu lines. Measured hydrostatic strains were half those measured in the Al/Cu lines. Heavy voiding was observed in the Al/Cu lines after cooling to the dwell temperature.

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