scholarly journals Identification of Fatigue Damage Stages in Polymer Composite Materials by using Acoustic Emission: Approach and Perspectives

2021 ◽  
Author(s):  
Oleg Bashkov ◽  
Anton Bryansky ◽  
Timofey Efimov ◽  
Roman Romashko
Keyword(s):  
Acoustic Emission ◽  
Composite Material ◽  
Polymer Composite ◽  
Fatigue Loading ◽  
Polymer Composite Material ◽  
Self Organizing Map ◽  
Local Formation ◽  
Adhesion Failure ◽  
The Matrix ◽  
Ae Signals

The work is devoted to the study of the mechanisms of damage accumulation in a polymer composite material (PCM) during fatigue loading. Mechanical testing of a fiberglass sample was carried out by cyclic tension accompanied by registration of acoustic emission (AE). For the recorded AE signals, the Fourier spectra were calculated and used for clustering with Kohonen self-organizing map. Relations between clusters and types of damage in the PCM structure were established. The analysis of the peak frequencies of the Daubechies D14-wavelet components of AE signals was carried out. Obtained results has allows one to describe the processes of destruction in the PCM sample. It has been established that, on the base of local formation of microdamages in the matrix and the fracture of the fibers detected during recording of the AE data, it is possible to predict the destruction of the polymer composite material, while the beginning of a material destruction can be registered if the damage identified as an adhesion failure is observed. Perspectives of application of adaptive fiber-optic AE sensors for structural monitoring of PCMs on the base of preliminary experimental results are considered and discussed.

scholarly journals Identification of acoustic emission sources under cyclic loading of the polymer composite material used in shipbuilding

2021 ◽  
pp. 28-33
Author(s):  
О.В. Башков ◽  
А.А. Брянский ◽  
Т.И. Башкова
Keyword(s):  
Acoustic Emission ◽  
Composite Material ◽  
Polymer Composite ◽  
Mechanical Test ◽  
Fatigue Loading ◽  
Polymer Composite Material ◽  
Second Stage ◽  
Kohonen Map ◽  
Ae Signals ◽  
Critical Intensity

Данная работа посвящена исследованию механизмов накопления повреждений в полимерном композиционном материале (ПКМ) в ходе усталостного нагружения. Механическое испытание образца стеклопластика проводили циклическим растяжением в сопровождении регистрации акустической эмиссии (АЭ). Для зарегистрированных сигналов АЭ рассчитывались спектры Фурье и использовались для кластеризации самоорганизующейся картой Кохонена (SOM). Полученные центроиды, для снижения количества анализируемых кластеров, разделяли на кластеры методом k-средних. Кластеры второго этапа кластеризации соотносились с типами повреждений в структуре ПКМ. Рассчитывались периоды критической интенсивности регистрации различных типов образующихся повреждений. Дополнительно проведён анализ пиковых частот уровней вейвлет декомпозиции Добеши 14 сигналов АЭ. На основании проведенных методов анализа данных АЭ описаны протекающие процессы разрушения в образце ПКМ. This work is aimed the study the mechanisms of damage accumulation in a polymer composite material (PCM) during fatigue loading. Mechanical test of a fiberglass sample was done by cyclic tension with acoustic emission (AE) registration. The Fourier spectra were calculated for the recorded AE signals and used for clustering with a self-organizing Kohonen map (SOM). The obtained centroids, in order to reduce the number of analyzed clusters, were divided into clusters by the k-means method. Clusters of the second stage clustering correlated with the types of damage in the structure of the PCM. The periods of the critical intensity of registration of various types of formed damages were calculated. Additionally, the peak frequencies of the levels of Daubechies 14 wavelet decomposition of AE signals was analyzed. Based on the methods for analyzing the AE data, the processes of destruction in the PCM sample are described.

scholarly journals IDENTIFICATION OF ACOUSTIC EMISSION SOURCES IN A POLIMER COMPOSITE MATERIAL UNDER THE CYCLE TENSION LOADING

2021 ◽  
pp. 19-27
Author(s):  
A. A. Bryansky ◽  
◽  
O. V. Bashkov ◽  
Keyword(s):  
Acoustic Emission ◽  
Structural Changes ◽  
Destructive Testing ◽  
Local Formation ◽  
Adhesion Failure ◽  
Highly Sensitive ◽  
The Matrix ◽  
Tension Loading ◽  
Non Destructive ◽  
Ae Signals

The structure of polymer composite materials (PCM) provides high mechanical properties but, at the same time, is highly sensitive to the formation of internal defects. Therefore, when designing, manufacturing products, and assessing their reliability in service, much attention is paid to the methods of non-destructive testing, among which the method of acoustic emission (AE) has proven itself to study structural changes in material under external influence. The paper deals with the identification of typical damages in fiberglass samples made of T11-GVS9 glass fiber cloth and DION 9300 FR binder and tested under cyclic tension using the AE method. In the work, the authors solved the problem of selecting the AE informative parameters and used a clustering method to identify the nature and the formation kinetics of the AE sources. The authors performed clustering using the Kohonen self-organization map (SOM) with the Fourier spectra calculated for the AE signals recorded during cyclic tests. Based on the peak frequencies analysis of the produced clusters, the researchers determined their nature and calculated the periods of critical accumulation. When characterizing the AE sources, the authors used the peak frequencies analysis of the wavelet spectra performed for different levels of decomposition. The authors determined the damage accumulation stages of samples during testing based on own research and research by other authors’ results. The study established that registration of AE signals identified as adhesion failure can be used to identify the onset of the material destruction and characterized the local formation of micro-damages in the matrix and fracture of fibers can be used to predict the destruction of PCM.

Estimation of stressed-deformed state of polymer composite material with hybrid matrix

2021 ◽  
Vol 0 (9) ◽  
pp. 2-7
Author(s):  
E. A. Kosenko ◽  
◽  
V. A. Nelyub ◽  
Keyword(s):  
Composite Material ◽  
Polymer Composite ◽  
Element Model ◽  
Polymer Composite Material ◽  
Silicon Matrix ◽  
Organic Silicon ◽  
The Matrix ◽  
Deformed State ◽  
Plastic Components ◽  
Elastic Characteristics

Properties of polymer composite material consisting of carbon fabric and two matrix types (epoxy and organic-silicon) have been studied. The main purpose of the organic-silicon matrix is to relax stresses arising in carbon-filled plastic components under loads and to decelerate (or stop) crack growth. The structure of the composite material was determined by using a tomography. On the basis of the structure, a finite-element model was developed and a calculation of the stressed-deformed state depending on elastic characteristics of the matrix was performed. A safety factor calculation was made. It was found out that the addition of organic-silicon material in the composite composition made possible to decrease stress values in the crack tip that considerably increased the service life of such materials.

DETERMINATION OF THE POLYMERIZATION DEGREE OF THE MATRIX OF POLYMER COMPOSITE MATERIAL USING ULTRASONIC METHOD

2019 ◽  
Vol 85 (4) ◽  
pp. 33-39
Author(s):  
Victor V. Murashov ◽  
Valery M. Aleksashin ◽  
Konstantin S. Mishurov
Keyword(s):  
Composite Material ◽  
Kinetic Parameters ◽  
Polymer Composite ◽  
Ultrasonic Method ◽  
Acoustic Method ◽  
Degree Of Polymerization ◽  
Polymer Composite Material ◽  
Ultrasonic Vibrations ◽  
The Matrix

The results of studying the efficiency of the laser-acoustic method of ultrasonic testing in determination of the degree of polymerization of the matrix of polymer composite material (PCM) are presented. We have studied the PCM samples used for manufacturing integrated structures. It is shown that excessive degree of polymerization of the preformed blanks leads to a decrease in the strength of connection of the structural elements and precludes obtaining the desired shape and geometric dimensions of the product. We developed fundamentally new diagnostic parameters, which are characterized by high reliability and accuracy of determination. To forecast sample curing regimes with given values of the degree of transformation, the reaction kinetics was analyzed using differential scanning calorimetry Experimental results used for calculation of the kinetic parameters were obtained on a thermoanalytical complex DSC 1 (Switzerland). The kinetic parameters of polymerization and degree of binder curing in plastics were determined by the thermal effect of the reaction. It is shown that when determining the degree of polymerization of a PCM matrix by an ultrasonic method (laser-acoustic method of exciting ultrasonic vibrations), the product of attenuation of the bottom signal of longitudinal ultrasonic vibrations by the signal round-trip time and energy of the structural noise (thus taking into account the porosity of the material), can be used as reliable parameters of diagnostics. The proposed method provides higher accuracy compared to other methods used for control of the degree of polymerization.

Detection of acoustic emission signals in the polymer composite material by adaptive fiber-optic sensors

2016 ◽  
Author(s):  
Oleg V. Bashkov ◽  
Roman V. Romashko ◽  
Valeriy I. Zaykov ◽  
Alexander E. Protsenko ◽  
Michail N. Bezruk ◽  
...  
Keyword(s):  
Acoustic Emission ◽  
Composite Material ◽  
Polymer Composite ◽  
Fiber Optic ◽  
Fiber Optic Sensors ◽  
Polymer Composite Material

Formation of mechanical properties of polymer composite materials with different types of hybrid matrices

2021 ◽  
pp. 28-34
Author(s):  
E. A. Kosenko ◽  
◽  
P. E. Demin ◽  
Keyword(s):  
Mechanical Properties ◽  
Composite Material ◽  
Composite Materials ◽  
Polymer Composite ◽  
Strength Properties ◽  
Polymer Composite Material ◽  
Polymer Materials ◽  
Polymer Composite Materials ◽  
Hybrid Matrix ◽  
The Matrix

The mechanical properties of polymer composite materials largely depend on the interfacial phenomena occurring on the interface between the matrix and reinforcing material. The addition of components to the matrix of polymer composite materials that retain their viscoelastic state during the molding process of the products makes possible to locally change the deformation-and-strength properties of a finished product, adapting it to the specified operating conditions. The viscoelastic components in the hybrid matrix form the third phase of the polymer composite material. Increasing the efficiency of interfacial layers of polymer composite materials with various types of hybrid matrices is the most important task of their development. The samples for microanalysis of the polymer composite material structure with various types of hybrid matrices were molded using the prepreg technology by vacuum molding on the basis of BT400 biaxial basalt fabric. Technical wax, anaerobic (Loctite 638) and organosilicon (Yunisil-9628) polymer materials were selected as the viscoelastic components of the hybrid matrix. In order to explain the reasons for the change in the deformation-and-strength properties of the obtained basalt plastics with various viscoelastic components in the composition of the hybrid matrix, microanalysis of their structure was carried out. A mechanism for choosing a scheme for the location of viscoelastic components in a matrix of polymer composite materials based on the provisions of combinatorial optimization is described.

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