Elastic and Plastic Deformation Behaviors of Lotus-Type Porous Copper

2010 ◽  
Vol 658 ◽  
pp. 332-335
Author(s):  
Masakazu Tane ◽  
Hideo Nakajima

The elastic and plastic deformation behaviors of lotus-type porous copper (lotus copper) with cylindrical pores oriented in one direction were investigated using two acoustic methods (resonant ultrasound spectroscopy and acoustic emission method). All the independent components of elastic stiffness were determined by resonant ultrasound spectroscopy combined with electromagnetic acoustic resonance method, which revealed that the Young’s modulus exhibits the anisotropy originating from the anisotropic porous structure and anisotropic matrix texture. The porosity dependence of the anisotropic Young’s modulus can be calculated by the micromechanics modeling based on effective-mean-field theory. The tensile deformation behavior of lotus copper was analyzed by acoustic emission method, which revealed that many burst acoustic emission signals are detected during the tensile deformation. This implies that many cracks are formed during the tensile deformation.

1985 ◽  
Vol 27 (6) ◽  
pp. 433-437
Author(s):  
L. M. Rybakova ◽  
N. S. Kuznetsov ◽  
I. A. Lipyanko ◽  
B. A. Prusakov ◽  
Yu. M. Reznikov

Materials ◽  
2018 ◽  
Vol 12 (1) ◽  
pp. 20
Author(s):  
Justyna Zapała-Sławeta ◽  
Grzegorz Świt

The study analyzed the possibility of using the acoustic emission method to analyse the reaction of alkali with aggregate in the presence of lithium nitrate. Lithium nitrate is a chemical admixture used to reduce adverse effects of corrosion. The tests were carried out using mortars with reactive opal aggregate, stored under the conditions defined by ASTM C227. The acoustic activity of mortars with a corrosion inhibitor was referred to linear changes and microstructure of specimens in the initial reaction stages. The study found a low acoustic activity of mortars with lithium nitrate. Analysis of characteristic parameters of acoustic emission signals, combined with the observation of changes in the microstructure, made it possible to describe the corrosion processes. As the reaction progressed, signals with different characteristics were recorded, indicating aggregate cracking at the initial stage of the reaction, followed by cracking of the cement paste. The results, which were referred to the acoustic activity of reference mortars, confirmed that the reaction of opal aggregate with alkali was mitigated in mortars with lithium nitrate, and the applied acoustic emission method enabled the detection and monitoring of ASR progress.


2016 ◽  
Vol 837 ◽  
pp. 198-202
Author(s):  
Luboš Pazdera ◽  
Libor Topolář ◽  
Tomáš Vymazal ◽  
Petr Daněk ◽  
Jaroslav Smutny

The aim of the paper is focused on the analysis of the mechanical properties of the concrete specimens with plasticizer at three point bending test by the signal analysis of the acoustic emission signal. The evaluations were compared the measurement and the results obtained with theoretical presumptions. The Joint Time Frequency Analysis applied on measurement data and its evaluation is described. It is well known that the Acoustic Emission Method is a very sensitive method to determine active cracks into structure. However, evaluation of acoustic emission signals is very difficult. A non-traditional method was used to signal analysis of burst acoustic emission signals recorded during three point bending test.


2014 ◽  
Vol 7 (2) ◽  
pp. 703-709 ◽  
Author(s):  
Kazuho Mizuta ◽  
Yukio Nishizawa ◽  
Koji Sugimoto ◽  
Katsuya Okayama ◽  
Alan Hase

2013 ◽  
Vol 66 ◽  
pp. 651-660 ◽  
Author(s):  
A. Ould Amer ◽  
A.-L. Gloanec ◽  
S. Courtin ◽  
C. Touze

2021 ◽  
Vol 70 (2) ◽  
pp. 40-46
Author(s):  
Takuya Kurihara ◽  
Matsuo Takuma ◽  
Taro Kono ◽  
Kaori Numata

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