Critical Stress of Microcracking in Alumina Evaluated by Acoustic Emission

1992 ◽  
pp. 59-72 ◽  
Author(s):  
Shuichi Wakayama ◽  
Hisashi Nishimura
Keyword(s):  
Acoustic Emission ◽  
Critical Stress

scholarly journals Application of Acoustic Emission Method to Determine Critical Stress in Fibre Reinforced Mortar Beams

2012 ◽  
Vol 37 (3) ◽  
Author(s):  
Zbigniew Ranachowski ◽  
Daria Jóźwiak–Niedźwiedzka ◽  
Andrzej M. Brandt ◽  
Tomasz Dębowski
Keyword(s):  
Acoustic Emission ◽  
Critical Stress ◽  
Acoustic Emission Method ◽  
Emission Method

scholarly journals ACOUSTICALLY ASSESSED INFLUENCE OF AIR PORE STRUCTURE ON FAILURE OF SELF-COMPACTING CONCRETES UNDER COMPRESSION / AKUSTIŠKAI ĮVERTINTA ORO PORŲ STRUKTŪROS ĮTAKA SUSITANKINANČIO BETONO SUSILPNĖJIMUI VEIKIANT GNIUŽDYMUI

2012 ◽  
Vol 18 (1) ◽  
pp. 60-70 ◽  
Author(s):  
Tomasz Gorzelańczyk
Keyword(s):  
Acoustic Emission ◽  
Pore Structure ◽  
Critical Stress ◽  
Failure Process ◽  
The Self ◽  
Cyclic Loads ◽  
Image Analyzer ◽  
Structure Parameters ◽  
Acoustic Emission Technique ◽  
Mercury Porosimeter

The paper presents the results of investigations into the influence of pore structure on the failure of self-compacting concretes modified with superplasticizers commonly used in construction. Pore structure examinations were carried out in practically the whole range of pore diameters by means of an image analyzer and a mercury porosimeter. The failure of the self-compacting concretes under compression, was investigated by the acoustic emission technique and other methods. The levels of cracking initiating stress σiand critical stress σcr, demarcating the different stages in the failure process, were determined. It has been shown that there is a relationship between the pore structure parameters and the levels. The fatigue strength of the self-compacting concretes was calculated from the experimental results and on this basis the suitability of the concretes for structures subject to cyclic loads was determined. Santrauka Straipsnyje pateikiami porų struktūros įtakos susitankinančio betono su superplastikliais susilpnėjimui tyrimų rezultatai. Buvo atlikti praktiškai visų skersmenų porų struktūros tyrimai naudojant vaizdo analizatorių ir gyvsidabrio porosimetrą. Susitankinančio betono susilpnėjimas esant gniuždymui buvo tiriamas akustinės emisijos ir kitais metodais. Nustatyti pleišėjimo lygiai ir įtampos, žymintys skirtingus susilpnėjimo lygius. Parodyta, kad yra ryšys tarp porų struktūros parametrų ir susilpnėjimo lygių. Pagal eksperimentinius rezultatus suskaičiuotas betono atsparumas ir nustatytas betono tinkamumas konstrukcijoms, atsižvelgiant į ciklines apkrovas.

Propagation of acoustic emission signals in metallic fuselage structure

2001 ◽  
Vol 148 (4) ◽  
pp. 169-177 ◽  
Author(s):  
R.P. Dalton ◽  
P. Cawley ◽  
M.J. Lowe
Keyword(s):  
Acoustic Emission

Comparison of random field strengths in (1-x)SrTiO3-xBiFeO3 and (1-x)SrTiO3-xBaTiO3 relaxor ferroelectrics by means of acoustic emission

2020 ◽  
Vol 92 (2) ◽  
pp. 20401
Author(s):  
Evgeniy Dul'kin ◽  
Michael Roth
Keyword(s):  
Acoustic Emission ◽  
Random Field ◽  
Electric Fields ◽  
Bias Field ◽  
Relaxor Ferroelectrics ◽  
External Bias ◽  
Field Strengths

In relaxor (1-x)SrTiO3-xBiFeO3 ferroelectrics ceramics (x = 0.2, 0.3 and 0.4) both intermediate temperatures and Burns temperatures were successfully detected and their behavior were investigated in dependence on an external bias field using an acoustic emission. All these temperatures exhibit a non-trivial behavior, i.e. attain the minima at some threshold fields as a bias field enhances. It is established that the threshold fields decrease as x increases in (1-x)SrTiO3-xBiFeO3, as it previously observed in (1-x)SrTiO3-xBaTiO3 (E. Dul'kin, J. Zhai, M. Roth, Phys. Status Solidi B 252, 2079 (2015)). Based on the data of the threshold fields the mechanisms of arising of random electric fields are discussed and their strengths are compared in both these relaxor ferroelectrics.

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