Application of metric entropy to determine properties of structural materials

Garbacz, G.; Kyzioł, L.

doi:10.1590/0104-1428.03119

Cited by 3 publications

(9 citation statements)

References 8 publications

(9 reference statements)

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“…Earlier tests carried out on materials showing a clear yield point showed a high agreement of the yield strength values obtained in accordance with the standard and the specified K-S entropy method [ 18 , 19 , 20 , 21 , 22 , 23 ]. On the basis of a series of laboratory tests carried out by the authors of the study for isotropic and anisotropic materials, it was assumed that the application of the K-S method allows to determine the transition of the material from the elastic to the plastic phase.…”

Section: Introductionsupporting

confidence: 65%

“…Works [ 18 , 19 , 20 , 21 , 22 , 23 ] present an overview of a measurement collection and a diagram for calculating K-S entropy for successive positions of measurement collections containing an n number of items, relative to measurement data.…”

Section: Methodsmentioning

confidence: 99%

“…The minimum value of metric entropy in the vicinity of the passage from elastic to plastic state is marked by the point that separates individual states of the process. The value of stress corresponding to the passage of the tested material from its elastic to its plastic state is determined on the basis of the “critical” point [ 18 , 19 , 20 , 21 , 22 , 23 ].…”

Section: Methodsmentioning

confidence: 99%

“…Measurement data includes 1000 to 2000 points in the elastic scope. The N number was adopted according to a formula applied in mathematical statistics in the construction of histograms: N ≤ 5 log k [ 18 , 19 , 20 , 21 , 22 , 23 ].…”

Section: Methodsmentioning

confidence: 99%

“…Examples are the graphs of the static tensile test, on the basis of which the internal dynamics of the material deformation process cannot be observed. The dynamics of the tensile deformation process of the sample in the form of chaotically arranged measurement points (especially in the elastic range of the material) can only be observed by significantly enlarging a part of the graph [ 18 , 19 , 20 , 21 , 22 ].…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Acoustic Emission and K-S Metric Entropy as Methods for Determining Mechanical Properties of Composite Materials

Kyzioł

Panasiuk

Hajdukiewicz

et al. 2020

Sensors

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Due to the unique properties of polymer composites, these materials are used in many industries, including shipbuilding (hulls of boats, yachts, motorboats, cutters, ship and cooling doors, pontoons and floats, torpedo tubes and missiles, protective shields, antenna masts, radar shields, and antennas, etc.). Modern measurement methods and tools allow to determine the properties of the composite material, already during its design. The article presents the use of the method of acoustic emission and Kolmogorov-Sinai (K-S) metric entropy to determine the mechanical properties of composites. The tested materials were polyester-glass laminate without additives and with a 10% content of polyester-glass waste. The changes taking place in the composite material during loading were visualized using a piezoelectric sensor used in the acoustic emission method. Thanks to the analysis of the RMS parameter (root mean square of the acoustic emission signal), it is possible to determine the range of stresses at which significant changes occur in the material in terms of its use as a construction material. In the K-S entropy method, an important measuring tool is the extensometer, namely the displacement sensor built into it. The results obtained during the static tensile test with the use of an extensometer allow them to be used to calculate the K-S metric entropy. Many materials, including composite materials, do not have a yield point. In principle, there are no methods for determining the transition of a material from elastic to plastic phase. The authors showed that, with the use of a modern testing machine and very high-quality instrumentation to record measurement data using the Kolmogorov-Sinai (K-S) metric entropy method and the acoustic emission (AE) method, it is possible to determine the material transition from elastic to plastic phase. Determining the yield strength of composite materials is extremely important information when designing a structure.

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Section: Introductionsupporting

confidence: 65%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Acoustic Emission and K-S Metric Entropy as Methods for Determining Mechanical Properties of Composite Materials

Kyzioł

Panasiuk

Hajdukiewicz

et al. 2020

Sensors

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Acoustic Emission and K-S Metric Entropy as Methods to Analyze the Influence of Gamma-Aluminum Oxide Nanopowder on the Destruction Process of GFRP Composite Materials

Panasiuk,

Dudzik,

Hajdukiewicz

et al. 2023

Materials

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Composites are materials that are widely used in industry, including yachting, railway and aviation. The properties of these materials can be modified by changing the type of reinforcement, the type of matrix, as well as the use of additives in the form of fillers and nanofillers that improve their mechanical or specific parameters. Due to the fact that these materials are often used for important structures, computational models using FEM tools may not be sufficient to determine the actual strength parameters, and what is more, to check them during operation. When designing structures made of composite materials, it is necessary to use high safety factors due to their behavior under several different types of loads, which is still difficult to determine precisely. This situation makes these structures much heavier and characterized by much higher strength properties than those that would actually be needed. In this article, the Kolmogorov-Sinai (K-S) metric entropy was used to determine the transition from the elastic to the viscoelastic state in GFRP (glass fiber reinforced polymer) composite materials without and with the addition of nanoaluminum, during a static tensile test. Additionally, the acoustic emission method was used during the research. This signal was further processed, and graphs were made of the number of events and the amplitude as a function of time. The obtained values were plotted on tensile graphs. The influence of the nano-filler on these parameters was also analyzed. The presented results show that it is possible to determine additional parameters affecting the strength of the structure for any composite materials.

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Influence of Gamma-Phase Aluminum Oxide Nanopowder and Polyester–Glass Recyclate Filler on the Destruction Process of Composite Materials Reinforced by Glass Fiber

Panasiuk,

Dudzik,

Hajdukiewicz

et al. 2024

Polymers

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Recycling of composite materials is an important global issue due to the wide use of these materials in many industries. Waste management options are being explored. Mechanical recycling is one of the methods that allows obtaining polyester–glass recyclate in powder form as a result of appropriate crushing and grinding of waste. Due to the fact that the properties of composites can be easily modified by adding various types of fillers and nanofillers, this is one of the ways to improve the properties of such complex composite materials. This article presents the strength parameters of composites with the addition of fillers in the form of polyester–glass recyclate and a nanofiller in the form of gamma-phase aluminum nanopowder. To analyze the obtained results, Kolmogorov-Sinai (K-S) metric entropy was used to determine the transition from the elastic to the viscoelastic state in materials without and with the addition of nanoaluminum, during a static tensile test. The tests included samples with the addition of fillers and nanofillers, as well as a base sample without any additives. The article presents the strength parameters obtained from a testing machine during a static tensile test. Additionally, the acoustic emission method was used during the research. Thanks to which, graphs of the effective value of the electrical signal (RMS) were prepared as a function of time, the parameters were previously identified as extremely useful for analyzing the destruction process of composite materials. The values obtained from the K-S metric entropy method and the acoustic emission method were plotted on sample stretching graphs. The influence of the nanofiller and filler on these parameters was also analyzed. The presented results showed that the aluminum nanoadditive did not increase the strength parameters of the composite with recyclate as a result of the addition of aluminum nanofiller; however, its addition influenced the operational parameters, which is reflected in a 5% increase in the UTS value (from 55% to 60%).

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Application of metric entropy to determine properties of structural materials

Cited by 3 publications

References 8 publications

Acoustic Emission and K-S Metric Entropy as Methods for Determining Mechanical Properties of Composite Materials

Acoustic Emission and K-S Metric Entropy as Methods for Determining Mechanical Properties of Composite Materials

Acoustic Emission and K-S Metric Entropy as Methods to Analyze the Influence of Gamma-Aluminum Oxide Nanopowder on the Destruction Process of GFRP Composite Materials

Influence of Gamma-Phase Aluminum Oxide Nanopowder and Polyester–Glass Recyclate Filler on the Destruction Process of Composite Materials Reinforced by Glass Fiber

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