scholarly journals Damage Assessment in Fibrous Composites Using Acoustic Emission

10.5772/31912 ◽  
2012 ◽  
Author(s):  
A.S. Paipetis ◽  
D.G. Aggelis
2021 ◽  
pp. 105678952199119
Author(s):  
Kai Yang ◽  
Qixiang Yan ◽  
Chuan Zhang ◽  
Wang Wu ◽  
Fei Wan

To explore the mechanical properties and damage evolution characteristics of carbonaceous shale with different confining pressures and water-bearing conditions, triaxial compression tests accompanied by simultaneous acoustic emission (AE) monitoring were conducted on carbonaceous shale rock specimens. The AE characteristics of carbonaceous shale were investigated, a damage assessment method based on Shannon entropy of AE was further proposed. The results suggest that the mechanical properties of carbonaceous shale intensify with increasing confining pressure and degrade with increasing water content. Moisture in rocks does not only weaken the cohesion but also reduce the internal friction angle of carbonaceous shale. It is observed that AE activities mainly occur in the post-peak stage and the strong AE activities of saturated carbonaceous shale specimens appear at a lower normalized stress level than that of natural-state specimens. The maximum AE counts and AE energy increase with water content while decrease with confining pressure. Both confining pressure and water content induce changes in the proportions of AE dominant frequency bands, but the changes caused by confining pressure are more significant than those caused by water content. The results also indicate that AE entropy can serve as an applicable index for rock damage assessment. The damage evolution process of carbonaceous shale can be divided into two main stages, including the stable damage development stage and the damage acceleration stage. The damage variable increases slowly accompanied by a few AE activities at the first stage, which is followed by a rapid growth along with intense acoustic emission activities at the damage acceleration stage. Moreover, there is a sharp rise in the damage evolution curve for the natural-state specimen at the damage acceleration stage, while the damage variable develops slowly for the saturated-state specimen.


Author(s):  
Danilo D'Angela ◽  
Marianna Ercolino ◽  
Costanzo Bellini ◽  
Vittorio Di Cocco ◽  
Francesco Iacoviello

1991 ◽  
Vol 117 (11) ◽  
pp. 2681-2698 ◽  
Author(s):  
Chengsheng Ouyang ◽  
Eric Landis ◽  
Surendra P. Shah

2012 ◽  
Vol 157-158 ◽  
pp. 140-143
Author(s):  
Jun Lu ◽  
Shao Wei Hu ◽  
Xiang Qian Fan

Based on the experiments, the parameters of acoustic emission signals were discussed about cracks, expansion and instability of concrete in this paper. The relationship between different acoustic emission signals of concrete were established on damage constitutive relation. A new method was provided by damage assessment for hydraulic structures.


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