scholarly journals Characterization of acoustic emission signals from particulate filled thermoset and thermoplastic polymeric coatings in four point bend tests

2011 ◽  
Vol 65 (23-24) ◽  
pp. 3609-3611 ◽  
Author(s):  
Y. Xu ◽  
B.G. Mellor
Keyword(s):  
Acoustic Emission ◽  
Polymeric Coatings ◽  
Bend Tests ◽  
Point Bend

Acoustic Emission Studies of Alumina-13% Titania Free-Standing Forms during Four-Point Bend Tests

2005 ◽  
Vol 80 (9) ◽  
pp. 2382-2394 ◽  
Author(s):  
Chung-Kwei Lin ◽  
Christopher C. Berndt ◽  
Sang-Ha Leigh ◽  
Kenji Murakami
Keyword(s):  
Acoustic Emission ◽  
Free Standing ◽  
Bend Tests ◽  
Point Bend ◽  
Emission Studies

Characterization of the Residual Stresses and Strength of Ceramic-Metal Braze Joints

2009 ◽  
Vol 131 (2) ◽  
Author(s):  
Matteo Galli ◽  
John Botsis ◽  
Jolanta Janczak-Rusch ◽  
Gerd Maier ◽  
Udo Welzel
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Finite Element Models ◽  
Plastic Response ◽  
X Ray Diffraction ◽  
Elastoplastic Properties ◽  
Bend Tests ◽  
Point Bend ◽  
Good Agreement

Residual stress relief in ceramic-metal joints produced by active brazing depends primarily on the plastic response of the filler metal. A procedure for the production and mechanical characterization of bulk active filler alloy specimens is developed. In parallel ceramic-metal joints are produced and tested. Residual stresses are measured by X-ray diffraction while the joint strength is assessed by four-point bend tests. The obtained elastoplastic properties of the filler are introduced into finite element models to predict the residual stresses in the joints and their behavior in bending. The results of the simulations show good agreement both with the residual stress measurements and with the results of four-point bend tests.

Mechanical Characterization of Diamond-Like Carbon (DLC) Coated Polycarbonates

1993 ◽  
Vol 308 ◽  
Author(s):  
Alex J. Hsieh ◽  
Paul Huang ◽  
Shankar K. Venkataraman ◽  
David L. Kohlstedt
Keyword(s):  
High Speed ◽  
Mechanical Tests ◽  
Dominant Mode ◽  
Transverse Cracks ◽  
High Speed Impact ◽  
Dlc Coating ◽  
Bend Tests ◽  
Point Bend ◽  
The Impact

ABSTRACTEvaluations of DLC coated polycarbonates have been carried out via high speed projectile impact, three point bend, and continuous microscratch tests. Radial and circumferential microcracks appeared on the back surfaces and near the regions of impact as a result of the high speed impact stresses. Despite the impact, the adhesion of the DLC coating in the area between the cracks remained, except in the immediate vicinity of impact. In the three point bend tests, transverse cracks developed and propagated in the DLC coating when the applied strain reached the fracture limit of the coating. No delamination occurred in the continuous microscratch tests; instead, cracking of the coating was observed in DLC coated polycarbonates. Microcracking was the dominant mode of failure which was consistent in these three diversed mechanical tests. Results of the SEM studies further confirmed microcracking prior to delamination as observed in the high speed impact tested coupons.

Acoustic Emission Studies of Thermal Barrier Coatings during Cyclic Four Point Bend Tests

1996 ◽  
Author(s):  
J. Voyer ◽  
F. Gitzhofer ◽  
M.L. Boulos ◽  
J. Dionne
Keyword(s):  
Acoustic Emission ◽  
Thermal Barrier Coatings ◽  
Peak Frequency ◽  
Thermal Barrier ◽  
Barrier Coatings ◽  
Emission Signal ◽  
Barrier Coating ◽  
Bend Tests ◽  
Point Bend ◽  
Plasma Sprayed

Abstract In this study, Acoustic Emission (AE) signals are used to monitor the degradation of plasma sprayed Thermal Barrier Coatings (TBC) using cyclic four point bend tests. Signal analysis both in time and frequency domains is carried out in order to identify the key parameters which can be used to classify the acoustic emission signals as a function of the damage mechanisms. This classification offers a mean of prediction of the long-term behavior of the thermal barrier coating based on the acoustic emission signal signature at the early stages of bench testing. The samples consist of a Nickel-based alloy blade coated with a duplex TBC made of a 150 μm thick bond coat covered with a 300 μm thick partially-stabilized zirconia coating. Tests were performed on unnotched and perpendicularly notched samples in order to discriminate the AE from perpendicular cracks. Two broadband transducers are used for acquisition of acoustic emission signals. Measuring the time between signal detection by each of the two transducers provides a means of determination of the location of the source of the acoustic signals. A classification of the signals based on their energy and their maximum peak frequency is presented. A comparison is made between the degradation mechanisms of TBC under thermal cycling conditions that were presented elsewhere (1) and the results of four point bend tests presented here.

Acoustic emission and X-ray computed microtomography characterization of damage accumulation in a woven Cf/SiC composite

2019 ◽  
Vol 155 ◽  
pp. 109748
Author(s):  
Yudong Xue ◽  
Qinglei Wang ◽  
Jianbao Hu ◽  
Haijun Zhou ◽  
Qingliang Shan ◽  
...  
Keyword(s):  
Acoustic Emission ◽  
Damage Accumulation ◽  
X Ray ◽  
Computed Microtomography ◽  
X Ray Computed

Characterization of acoustic emission analysis in applications for inhalation device performance assessment

2019 ◽  
Vol 563 ◽  
pp. 304-313
Author(s):  
Mikael Boberg ◽  
Lisa Holmstén ◽  
Mats Josefson ◽  
Roland Greguletz ◽  
Kyrre Thalberg ◽  
...  
Keyword(s):  
Acoustic Emission ◽  
Performance Assessment ◽  
Device Performance ◽  
Emission Analysis ◽  
Inhalation Device ◽  
Acoustic Emission Analysis
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