scholarly journals Effect of Moisture Distribution on Velocity and Waveform of Ultrasonic-Wave Propagation in Mortar

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 790
Author(s):  
Shinichiro Okazaki ◽  
Hiroma Iwase ◽  
Hiroyuki Nakagawa ◽  
Hidenori Yoshida ◽  
Ryosuke Hinei

Considering that the ultrasonic method is applied for the quality evaluation of concrete, this study experimentally and numerically investigates the effect of inhomogeneity caused by changes in the moisture content of concrete on ultrasonic wave propagation. The experimental results demonstrate that the propagation velocity and amplitude of the ultrasonic wave vary for different moisture content distributions in the specimens. In the analytical study, the characteristics obtained experimentally are reproduced by modeling a system in which the moisture content varies between the surface layer and interior of concrete.

2019 ◽  
Vol 69 (1) ◽  
pp. 5-16 ◽  
Author(s):  
Raquel Gonçalves ◽  
Rafael Gustavo Mansini Lorensani ◽  
Monica Ruy ◽  
Nadia Schiavon Veiga ◽  
Gabriela Müller ◽  
...  

Abstract Wood-processing industries must be able to estimate the properties of wood to properly manage the wood production chain. For this estimation, changes in certain characteristics over time must be identified so that they can be used to rapidly differentiate a clone or species. Of interest are acoustical, geometrical, physical, and mechanical properties, all measurable in seedlings. Thus, the objective of this research was to analyze the evolution of the ultrasonic wave propagation velocity, diameter, height, basic density, strength, and stiffness starting in nursery seedlings at 3 months of age to trees at 6 years of age, which is the cutting age used by the pulp and paper industry in Brazil. The experiment was conducted in 121 seedlings and 270 trees of three Eucalyptus clones. Within the age range analyzed, the results indicated that all parameters have the potential to be used in a predictive model to estimate the future quality of clones, although the predictive value of these parameters varies. The ultrasonic wave propagation velocity was the only property that maintained the coherent differences among clones from the seedling to the cutting age (6 yr old). The strength, stiffness, diameter, and height maintained coherence from 12 months to the cutting age, whereas the basic density was maintained from the age of 24 months to the cutting age. We hope that these results will contribute to improving the methods to select clones.


2010 ◽  
Vol 670 ◽  
pp. 198-206 ◽  
Author(s):  
M.A. Bramantya ◽  
H. Takuma ◽  
J. Kuroiwa ◽  
T. Sawada

The rheological response of magnetorheological fluid (MRF) results from the polarization induced in the suspended particles by application of an external magnetic field. Characteristics of an MRF depend on the volume faction, that is the percentage of magnetic particles in the carrier liquid. We propose a qualitative investigation of these volume fraction effects by measuring properties of ultrasonic wave propagation velocity in MRFs having various volume fractions. The ultrasonic wave propagation velocity changes under the effect of an external magnetic field as a result of arrangement of clusters along the direction of the field in the MRF.


2016 ◽  
Vol 140 (5) ◽  
pp. 3710-3717 ◽  
Author(s):  
Toshiho Hata ◽  
Yoshiki Nagatani ◽  
Koki Takano ◽  
Mami Matsukawa

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