Investigation of Compressive Damage Mechanisms in 3D Braided Composites by the Acoustic Emission Events Energy and Amplitude

2013 ◽  
Vol 274 ◽  
pp. 393-397 ◽  
Author(s):  
Shi Yan ◽  
Shi Dong Pan ◽  
Dong Hua Li ◽  
Ji Cai Feng
Keyword(s):  
Acoustic Emission ◽  
Deformation Behavior ◽  
Compressive Loading ◽  
Damage Mechanism ◽  
Braided Composites ◽  
Damage Mechanisms ◽  
3D Braided Composites ◽  
Damage Process ◽  
Compressive Damage ◽  
Fracture Growth

The deformation behavior and damage mechanism of 3-D carbon/epoxy braided composites with different braiding angles under the monotonic compressive loading are investigated by the acoustic emission (AE) technique. The damage process is divided into several different regions based on the change of the accumulative AE event counts. Correlations between the damage mechanisms and the AE results are established in terms of the events energy and amplitude. These correlations can be used to monitor the fracture growth process in the braided composites. Experimental results reveal that the AE technique is an effective tool for identifying damage mechanisms.

Coupling effect of temperature and braided angle on compressive behaviors of 3D braided carbon–epoxy composite at low temperature

2016 ◽  
Vol 51 (18) ◽  
pp. 2531-2547 ◽  
Author(s):  
Hailou Wang ◽  
Baozhong Sun ◽  
Bohong Gu
Keyword(s):  
Room Temperature ◽  
Coupling Effect ◽  
Damage Zone ◽  
Orientation Angle ◽  
Effect Of Temperature ◽  
Braided Composites ◽  
Temperature Dependent ◽  
3D Braided Composites ◽  
Compressive Damage ◽  
Carbon Fiber Epoxy

This paper reports the influence of temperature and braided angle on compressive behaviors of 3D braided carbon fiber–epoxy composites. The compressive behaviors of the 3D braided with three braided angles (26°, 35° and 48°) were tested at various temperatures (−100℃, −50℃, 0℃, 20℃). The compressive damage morphologies were observed with SEM photographs. It was observed that the temperature and the braided angle have significant effect on the longitudinal compressive behaviors of 3D braided composites. The overall effect of braided angle on the 3D braided composites was greater than the temperature. The influence of the braided angle on the compressive behaviors is from the yarn orientation angle, while the influence of the temperature is from the temperature-dependent behaviors of the epoxy resin. Under low temperatures, the 3D braided composite behaved as brittle material and the compressive damage was easier than that of room temperature. The changes of yarn trajectory also led to generate the damage zone, especially in the edge and surface regions of the 3D braided composites.

Experimental Investigation of Tensile Damage Mechanisms on 3-D Braided Composites with AE

2013 ◽  
Vol 345 ◽  
pp. 290-293 ◽  
Author(s):  
Shi Yan ◽  
Li Li Jiang ◽  
Dong Hua Li
Keyword(s):  
Fracture Process ◽  
Event Rate ◽  
Peak Frequency ◽  
Textile Composites ◽  
Displacement Curve ◽  
Braided Composites ◽  
Cumulative Energy ◽  
Damage Mechanisms ◽  
3D Braided Composites ◽  
Fracture Processes

In this paper, the fracture process of 3D four-directional carbon/epoxy braided composites with different braiding angles under the monotonic tensile loading were investigated by the acoustic emission (AE) technique. The AE cumulative energy, event rate, amplitude, and the peak frequency were analyzed. At the same time, combining with the load-displacement curve varying feature, the fracture processes were divided into different stages to deeply understand the damaged mechanisms of the textile composites. Furthermore, the fracture surfaces of the specimens were observed under optical microscopy. Results reveal that the behavior of AE parameters described well the fracture process in the 3D braided composites with different braiding angles, and the damage mechanisms of the composites can be successfully identified by AE characteristics.

scholarly journals Damage mechanisms assessment of hybrid carbon/flax fibre composites using acoustic emission

2019 ◽  
Vol 283 ◽  
pp. 03003 ◽  
Author(s):  
Mariem Ben Ameur ◽  
Jean-Luc Rebiere ◽  
Abderrahim El Mahi ◽  
Moez Beyaoui ◽  
Moez Abdennadher ◽  
...  
Keyword(s):  
Acoustic Emission ◽  
Composite Laminates ◽  
Multivariable Analysis ◽  
Damage Mechanism ◽  
Tensile Tests ◽  
Flax Fibre ◽  
Acoustic Energy ◽  
Uniaxial Tensile ◽  
Damage Mechanisms ◽  
Hybrid Carbon

The purpose of the present experimental study is to describe the damage mechanisms occurring in epoxy matrix composites reinforced with hybrid carbon-flax fibres. The samples tested were consist of unidirectional carbon and flax fibre plies with different stacking sequences. Composite laminates were manufactured by hand lay-up process. The specimens were tested under uniaxial tensile loading. The tests carried out were monitored by the acoustic emission (AE) technique. The results obtained during the monotonic tensile tests were analyzed in order to identify the damage mechanisms evolutions. The recorded events were classified with the k-means algorithm which is a statistical multivariable analysis. In addition, it was an unsupervised classification according to temporal descriptors. The percentage of each damage mechanism to the global failure was evaluated by the hits number and the acoustic energy activity. The AE technique was correlated with scanning electron microscopy (SEM) observations to identify the typical damage mechanisms.

Identification of the concrete damage degree based on the principal component analysis of acoustic emission signals and neural networks

2020 ◽  
Vol 62 (5) ◽  
pp. 517-524
Author(s):  
Yan Wang ◽  
G. Jie ◽  
W. Na ◽  
Y. Chao ◽  
Z. Li ◽  
...  
Keyword(s):  
Neural Network ◽  
Principal Component Analysis ◽  
Acoustic Emission ◽  
Principal Components ◽  
Principal Component ◽  
Damage Mechanism ◽  
Component Analysis ◽  
Damage Degree ◽  
Concrete Damage ◽  
Damage Process

Abstract This paper aims to improve the calculation efficiency and accuracy of concrete damage degree identification, and then to analyze the damage mechanism of concrete damage. First, the correlation analysis and principal component analysis of 15 characteristic parameters of acoustic emission signals accompanying concrete uniaxial compression and splitting damage process are performed through which the dimension is reduced into 5 non-correlated principal components. Then, based on the analysis of the relationship between each principal component and the damage and cracking mechanism of concrete, the damage degree of concrete is identified as an input variable of the BP neural network. The results show that the 5 principal components effectively eliminate redundant information and carry information on the failure mechanism of concrete damage and the damage process. Principal component analysis and the neural network are used to achieve the accurate recognition of acoustic emission parameters and the degree of concrete damage.

Assessing the Fracture and Damage Process in Recycled Aggregate Concrete under Compressive Loading by Acoustic Emission

2010 ◽  
Vol 163-167 ◽  
pp. 2528-2531
Author(s):  
Seung Hyun Ryu ◽  
Young Oh Lee ◽  
Sun Woo Kim ◽  
Hyun Do Yun
Keyword(s):  
Acoustic Emission ◽  
Nondestructive Test ◽  
Crack Growth ◽  
Compressive Loading ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Aggregate Concrete ◽  
Damage Process ◽  
Degree Of Damage ◽  
Ae Signals

Acoustic emission (AE) is a powerful nondestructive test that can be used to characterize cracking, growth of cracks, and the degree of damage. This technique is clearly distinguished from other nondestructive techniques as it is a nondestructive test that estimates the degree of damage to concrete. In this study, the AE signals emitted during failure, according to the strength of recycled aggregate concrete specimens was examined, in order to characterize them using existing research results and evaluation theories. In addition, it is demonstrated that AE can be utilized to identify crack source and the mechanism of crack growth, which were monitored using a software program developed from the theory of the location of the source of a microcrack.

scholarly journals Challenges and Limitations in the Identification of Acoustic Emission Signature of Damage Mechanisms in Composites Materials

2018 ◽  
Vol 8 (8) ◽  
pp. 1267 ◽  
Author(s):  
Nathalie Godin ◽  
Pascal Reynaud ◽  
Gilbert Fantozzi
Keyword(s):  
Acoustic Emission ◽  
Health Management ◽  
Propagation Distance ◽  
Damage Mechanism ◽  
Surface Interactions ◽  
Stress Waves ◽  
Classification Algorithms ◽  
Damage Mechanisms ◽  
Composites Materials ◽  
Ae Signal

Acoustic emission is a part of structural health monitoring (SHM) and prognostic health management (PHM). This approach is mainly based on the activity rate and acoustic emission (AE) features, which are sensitive to the severity of the damage mechanism. A major issue in the use of AE technique is to associate each AE signal with a specific damage mechanism. This approach often uses classification algorithms to gather signals into classes as a function of parameters values measured on the signals. Each class is then linked to a specific damage mechanism. Nevertheless, each recorded signal depends on the source mechanism features but the stress waves resulting from the microstructural changes depend on the propagation and acquisition (attenuation, damping, surface interactions, sensor characteristics and coupling). There is no universal classification between several damage mechanisms. The aim of this study is the assessment of the influence of the type of sensors and of the propagation distance on the waveforms parameters and on signals clustering.

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