Electromagnetic Acoustic Resonance Method for Measuring Stresses in Metal Plates

Author(s):  
M. Hirao ◽  
H. Ogi ◽  
T. Yamasaki ◽  
H. Fukuoka
Author(s):  
V.I. Tarasevych ◽  
◽  
Yu.G. Gasan ◽  
V.B. Dolgoshey ◽  
◽  
...  

The paper considers the issues of studying the structure formation of binders during hardening to determine the optimal moments of mechanical action on gypsum concrete specimens, which makes it possible to optimize the technology of their impregnation with sulfur melt. The time dependence of the elastic modulus of a hardening, binder is its important physicochemical characteristic, since it is used to objectively identify the stages of structure formation, to simulate the processes occurring at each of the stages. It is noted that the method of acoustic resonance of bending vibrations, in the case of hardening binders, needs correction with respect to the measurement technique and interpretation of the results obtained. The kinetics of the resonance frequency of a sample consisting of a rigid cell and a dispersion poured into it is a function of the elastic properties of the cell, the dispersion itself, the contact zone of the dispersion with cell and therefore cannot be used for either qualitative or quantitative analysis of the kinetics of hardening. Taking into account the elasticity of cuvette is necessary to obtain reliable information. It has been established that in the presence of shrinkage or significant expansion of the binder, the study of structure formation by the resonance method should be carried out in plastic cuvettes. Regardless of shrinkage, the use of a cuvette requires compulsory consideration of its elastic properties. It is advisable to objectively distinguish the stages of structure formation on the basis of the kinetics of not the dynamic modulus of elasticity itself, but the rate of its change. The time dependence of the logarithmic damping decrement is also an important characteristic of the concrete structure. The studies carried out make it possible to obtain serogypsum composites with the necessary performance characteristics and to manufacture elements of architectural décor, wall fencing products of increased aesthetics, durability and reliability from them.


2020 ◽  
Vol 253 ◽  
pp. 112804 ◽  
Author(s):  
Qin Wei ◽  
Liyong Zhu ◽  
Jianguo Zhu ◽  
Lijun Zhuo ◽  
Wenfeng Hao ◽  
...  

1994 ◽  
Vol 60 (569) ◽  
pp. 250-257 ◽  
Author(s):  
Hirotsugu Ogi ◽  
Masahiko Hirao ◽  
Hidekazu Fukuoka

2008 ◽  
Vol 580-582 ◽  
pp. 113-116 ◽  
Author(s):  
Kinya Mitani ◽  
Masahito Mochizuki ◽  
Masao Toyoda

Development of a non-contact method for measuring the degree of corrosion is highly desired by those who are involved in the maintenance and control of steel structures. Increasingly, it is expected that application of an electromagnetic acoustic technology that does not require a coupling medium will meet this demand. Various problems have been reported regarding measuring thickness of a corroded material using the resonance method. In order to clarify these problems, it is important to make evaluations based on the resonance spectrum that corresponds to the thickness of each plate. In this paper, experiments using grooved specimens for a basic investigation were performed and a new method for wall-thinning measurement based on the resonance spectrum amplitude was proposed. In addition, examination was performed by using a numerical simulation about this method’s detection principle.


Author(s):  
P Adiyasuren ◽  
BB Damdinov ◽  
A Tsend-Ayush ◽  
E Norgov

An experimental study of the shear parameters of viscoelastic liquids is carried out by the acoustic resonance method based on the changes in the natural frequency and Q factor of a piezoelectric quartz resonator. The liquid to be studied is placed between a stationary quartz strap and the piezoelectric quartz crystal vibrating at the resonance frequency. For a set of drilling mud, the values of the real and imaginary shear module are obtained at a frequency of 74 kHz. The measurements are performed with a liquid layer thickness much smaller than the shear wavelength. It is shown that the shear modulus decreases with increasing strain amplitude. A hole-cluster model based on the Isakovich- Chaban nonlocal diffusion theory is proposed for explaining the low-frequency viscoelastic relaxation process.DOI: http://dx.doi.org/10.5564/pmas.v0i4.46 Proceedings of the Mongolian Academy of Sciences 2009 No 4 pp.53-58


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