FORECASTING CHARACTERISTICS OF COMPOSITE STRENGTH ON THE BASIS OF PREFORMS IN ELEMENTS OF BUILDING STRUCTURES

Currently, wicker composite structures for various purposes are widely used in many industries. The use of such preforms allows to provide the possibility of automation of production, high speed and efficiency of the process of manufacturing polymeric composite materials and structures based on them. Knowledge of their properties allows you to optimize the production of structures with the necessary parameters during design. In the article the model of composite material on the basis of wicker reinforcement was further developed. For the practical implementation of this model, it is sufficient to test material samples with three different angles between the harnesses, for example, ± 30º, ± 45º and ± 60º. A mathematical description of the model is given. The model made it possible to predict the physical and mechanical characteristics of the composite material when it is laid out on curved surfaces. At the same time some fictitious limits of durability of a composite are defined. This is due to the fact that each value of the angle between the harnesses corresponds to its physical and mechanical characteristics of the unidirectional composite material. In this case, the ultimate strength curves necessarily pass through the points corresponding to the experimental data. The article shows that the possible deviations of the strength limits in the range of angles between the harnesses will lie within the range of characteristics obtained by testing. The article shows that in the realized interval of angles between the harnesses, almost any polynomial criterion of strength will accurately describe the strength of the composite reinforced with a braided sleeve. The obtained parameters, in contrast to the existing ones, allow to predict the strength characteristics of the composite on the basis of braided sleeves depending on the positioning and location of the material on the forming surface. The obtained results are the basis for solving the problems of calculating the strength of building structures from composite materials based on wicker preforms.

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Determination of the Optimal Structure of a Layered Composite Material for Maximum Strength Characteristics

Materials Science Forum ◽

10.4028/www.scientific.net/msf.1040.124 ◽

2021 ◽

Vol 1040 ◽

pp. 124-131

Author(s):

Ljubov Aleksandrovna Bokhoeva ◽

I.O. Bobarika ◽

A.B. Baldanov ◽

Vitaly Evdokimovich Rogov ◽

Anna S. Chermoshentseva

Keyword(s):

Composite Material ◽

Composite Materials ◽

Mechanical Characteristics ◽

Minimum Weight ◽

Layered Composite ◽

Number Of Layers ◽

Reinforcing Material ◽

Intensive Development ◽

Physical And Mechanical Characteristics

Due to the intensive development of composite materials and technologies for producing parts from them, they are increasingly used in various industries, including the manufacture of products with increased requirements for the characteristics of final products (strength, stiffness, minimum weight, etc.). In this regard, the authors analyzed the possibility to optimize the layered structure of a composite material in order to give it a pronounced predictable anisotropy of properties required for the final product. Thus, the influence of the orientation of the fibers of the reinforcing material in different layers of the package and the number of layers of the package on the physical and mechanical characteristics of the hypothetical product were analyzed. The problem was solved through the example of the development of a wing for a hypothetical UAV.

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Physical and Mechanical Characteristics of a Pine Thermowood Composition during Barothermal Treatment

Lesnoy Zhurnal (Forestry Journal) ◽

10.37482/0536-1036-2021-2-143-155 ◽

2021 ◽

pp. 143-155

Author(s):

Yuri Skurydin ◽

◽

Elena Skurydina ◽

Rushan Safin ◽

Almira Khabibulina ◽

...

Keyword(s):

Composite Material ◽

Composite Materials ◽

Mechanical Characteristics ◽

Processing Conditions ◽

Active Components ◽

Hydrophobic Properties ◽

Pine Wood ◽

Wood Tissue ◽

Barothermal Treatment ◽

Physical And Mechanical Characteristics

The studies are aimed at forming ideas on the structure and properties of composite materials obtained from pine wood and the processes occurring in the structure of wood tissue. The article presents the data on the influence of the conditions of barothermal treatment of pine wood samples by the method of explosive autohydrolysis on the properties of a thermowood composition. The composite material is obtained by hot pressing. The influence on density, strength and hydrophobic characteristics was studied. A series of samples was made under different conditions of the explosive autohydrolysis rigidity factor; at a temperature of 200 °C and the process duration from 0.08 to 10 min. All samples of composite material were obtained without the use of additional components. It was found that the increase in the hydrolysis rigidity factor leads to a decrease in the density of hydrolyzed wood from 440 to ~350 kg/m3. There is no fragmentation of wood samples with the selected processing parameters. Hot pressing of hydrolyzed wood obtained under conditions of low or moderate rigidity is accompanied by a linear increase in the density of the thermowood composite material from ~440 to 500 kg/m3. The consequence of a further increase in the rigidity factor is a slowdown in the rate of increase in the density of the composite material. The conditional boundary that determines the achievement of the maximum number of cross-linked intermolecular structures in the composite material corresponds to the rigidity factor of 3000–4500 min. More rigid processing conditions cause intensification of thermal degradation processes. The dependence of hydrophobic characteristics on the rigidity of the barothermal treatment conditions is complex. At the rigidity factor of 1000–3000 min, an extreme point is observed, before which the hydrophobic properties of the material deteriorate. Its water absorption and swelling increase from 50 to 130 % and from 15 to 54 %, respectively. The hydrophobic performance is significantly improved after reaching the extreme point. Water absorption and swelling reduce to ~20 % and ~10 %, respectively. Mild hydrolysis conditions do not result in a material with consistently high hydrophobic properties. The cross-linked structures are not enough to form a strong and water-resistant composition, and as a consequence, the hydrophobic characteristics deteriorate. Increasing the value of the hydrolysis rigidity factor increases the number of active components. Additional intermolecular bonds formed during pressing improve hydrophobic characteristics. The obtained results can be used in the creation of models of processes occurring in the structure of lignocellulose substance during explosive autohydrolysis and in the preparation of composite materials based on it. Optimal parameters of barothermal treatment for obtaining composite materials with specified physical and mechanical characteristics can be determined. Barothermal treatment of solid pine wood by explosive autohydrolysis contributes to the occurrence of chemically active components in the structure of wood tissue. Their number depends on the rigidity of the processing conditions. The properties of the resulting thermowood composition depend on the conditions of explosive autohydrolysis.

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ANALYSIS OF STRENGTH CRITERIA IN THE DESIGN OF PRODUCTS FROM COMPOSITE MATERIALS

Bulletin of National Technical University of Ukraine Kyiv Polytechnic Institute Series Instrument Making ◽

10.20535/1970.61(1).2021.237094 ◽

2021 ◽

pp. 46-51

Author(s):

Andrzej Dzierwa ◽

Nataliia Stelmach

Keyword(s):

Composite Material ◽

Composite Materials ◽

Optimal Design ◽

Composite Structures ◽

Single Layer ◽

Unidirectional Composite ◽

Strength Criteria ◽

Optimal Criterion ◽

Allowable Load ◽

Unidirectional Composite Material

Technological progress gives rise to the continuous expansion of the class of structural materials and the improvement of their properties. The appearance of new materials is due to the natural desire to increase the efficiency of the structures under development. One of the most striking manifestations of progress in the development of materials, structures and technology is associated with the development and application of composite materials. Composites have a number of obvious advantages over other materials, in particular over metals. Such advantages are high specific strength and rigidity, high corrosion resistance, good ability to withstand alternating loads and others. It should be noted another, perhaps the most important feature of composites - is the ability to change the properties of the material in accordance with the purpose of the structure and the nature of its load during operation. Under the influence of loads on the structure, its strength is estimated by the ultimate state of the materials of the structural elements. When a boundary state arises in a material, its transition to another mechanical state - elastic, plastic, or fracture state - occurs. This article aims to determine the optimal criterion for the strength of composite material that takes into account different values of ultimate stresses not only in different directions of the coordinate axes, but also to stretch and compress and further calculate the maximum allowable load for single-layer unidirectional composite material During the research the main properties of composite materials, methods of manufacturing parts from composite material, their main properties and methods of destruction were considered. The characteristics of the strength criteria of composite materials are given, the most suitable for calculating the maximum value of the allowable load for a single-layer unidirectional composite material is determined. The proposed approach to the optimal design of elements of single-layer composite structures may be of interest to developers of numerous and analytical methods for solving problems of optimal design of more complex structures.

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Promising hybrid fabrics based on carbon and aramid fibers as a reinforcing filler for polymer composites

Voprosy Materialovedeniya ◽

10.22349/1994-6716-2019-98-2-86-95 ◽

2019 ◽

pp. 86-95 ◽

Cited By ~ 1

Author(s):

G. F. Zhelezina ◽

V. G. Bova ◽

S. I. Voinov ◽

A. Ch. Kan

Keyword(s):

Composite Material ◽

Polymer Composites ◽

Carbon Fibers ◽

Mechanical Characteristics ◽

High Strength ◽

High Modulus ◽

Hybrid Composite Material ◽

Hybrid Fabric ◽

Reinforcing Filler ◽

Physical And Mechanical Characteristics

The paper considers possibilities of using a hybrid fabric made of high-modulus carbon yarn brand ZhGV and high-strength aramid yarns brand Rusar-NT for polymer composites reinforcement. The results of studies of the physical and mechanical characteristics of hybrid composite material and values of the implementation of the strength and elasticity carbon fibers and aramid module for composite material are presented.

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Amorphous fiber based on the Fe-B-C molten system for bulk reinforcement of concrete

MATEC Web of Conferences ◽

10.1051/matecconf/201824503019 ◽

2018 ◽

Vol 245 ◽

pp. 03019 ◽

Cited By ~ 2

Author(s):

Artemiy Cherkashin ◽

Yasmin Begich ◽

Polina Sherstobitova ◽

Oleg Tolochko

Keyword(s):

Tensile Strength ◽

Compressive Strength ◽

Mechanical Characteristics ◽

Test Material ◽

Comparative Tests ◽

Physical And Mechanical Characteristics

The article deals with the use of amorphous fiber of the Fe-B-C system, which was obtained by spinning the melt. Comparative tests of the samples made on the basis of the test material on the compressive strength and tensile strength of the traditional destructive method were made. The conductivity of the samples was also tested. Physical and mechanical characteristics of the material are obtained.

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The Influence of Composite Polymeric Materials Topology Over the Shearing Modulus Using Virtual Instruments

Materiale Plastice ◽

10.37358/mp.18.4.5067 ◽

2018 ◽

Vol 55 (4) ◽

pp. 524-530

Author(s):

Marinela Marinescu ◽

Larisa Butu ◽

Claudia Borda ◽

Delicia Arsene ◽

Mihai Butu

Keyword(s):

Composite Material ◽

Composite Materials ◽

Virtual Instrument ◽

Mechanical Characteristics ◽

Polymeric Materials ◽

Mechanical Impedance ◽

Impedance Analysis ◽

Cross Linking ◽

Labview Software ◽

Different Temperatures

This study presents research regarding the calculation of the mechanical characteristics of composite polymeric materials. By using LabVIEW� software a virtual instrument was created used for monitoring in real time the process of cross-linking the composite polymeric materials. The experiments were realized based on composite materials containing epoxy/fiberglass resin of different topologies. By means of the virtual instrument and of a sensor created based on the mechanical impedance analysis, implanted in the composite material, it was determined the G shearing module of the composite material at different temperatures.

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Damage in Composite Material: A Microwave Detection

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.605.303 ◽

2014 ◽

Vol 605 ◽

pp. 303-305

Author(s):

Jerome Rossignol ◽

Alain Thionnet

Keyword(s):

Composite Materials ◽

Composite Structures ◽

Dielectric Material ◽

Low Cost ◽

Unidirectional Composite ◽

Microstrip Resonator ◽

Microwave Frequencies ◽

Fibre Break ◽

Materials Used ◽

Non Destructive

In the field of the transport, the increase of the security rule recommends to a periodic control of the structure to detect damage due to mechanical loadings. Now, current materials, used in the case of transport applications, are the composite materials. The methods, to control these materials or composite structures, need to be low cost, non-destructive, in-situ and swiftness as far as possible. The scientific literature reports many methods to control the damage in composite materials and structures. However the above requirements and the adaptation to composite materials reduce the number of methods that can be used. Currently, the adapted methods are based on infrared thermography, acoustical emission, EMIR (ElectroMagnetic InfraRed) or microwave imagery. We present an innovative non-destructive method of detecting damages in composite materials. The method is based on the observation and analysis of the modification in dielectric material resulting from damage. The originality of this method is that the diagnostic is obtained by using a microstrip resonator at microwave frequencies. The feasibility of the method is demonstrated by the detection of a fibre break into an unidirectional composite submitted to a flexural loading. The fibre break is the damage to detect. The perspective of this work is to develop a quantification and a localization of damages.

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Refractory Core-Shell Powders for Additive Industries

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.265.529 ◽

2017 ◽

Vol 265 ◽

pp. 529-534 ◽

Cited By ~ 1

Author(s):

Sergey P. Bogdanov ◽

A.P. Garshin

Keyword(s):

Thin Films ◽

Silicon Carbide ◽

Composite Materials ◽

Boron Nitride ◽

Tungsten Carbide ◽

Mechanical Characteristics ◽

Core Shell ◽

Refractory Materials ◽

Iodide Transport ◽

Physical And Mechanical Characteristics

The finished products obtained when the surfaces of powders of refractory materials (diamond, boron nitride, silicon carbide, tungsten carbide, tungsten) were coated with thin films by the method of iodide transport are presented. The developed method enables to obtain powder composite materials of core-shell type that have surface thickness varying in the range from 1 nm to several micrometers. From the powders modified by the films of metals and thier compounds composite materials were developed, their physical and mechanical characteristics were studied. The characteristics turned out to be substantially higher in comparison to materials sintered from the same powders but without coating. The probable fields of use of the composites in question were determined.

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On the influence of the shaped charge liner manufacture technology on the high-speed element characteristics

Engineering Journal Science and Innovation ◽

10.18698/2308-6033-2020-10-2020 ◽

2020 ◽

Author(s):

V.I. Kolpakov ◽

N.A. Kudyukov

Keyword(s):

High Speed ◽

Mechanical Characteristics ◽

Physical And Mechanical Properties ◽

Shaped Charge ◽

Design Parameters ◽

Geometrical Parameters ◽

Liner Material ◽

Metal Spinning ◽

Cold Stamping ◽

Physical And Mechanical Characteristics

The paper introduces the results of numerical simulation of the functioning of shaped charges, whose liners are made of different materials. As a result of their functioning, these charges form high-speed elements. Typically, liners for such charges are produced by the cold stamping technology. An alternative method for producing the liners is metal spinning. Moreover, a spin formed liner is expected to have higher physical and mechanical properties compared to a stamped liner made of the same material and having the same geometrical parameters. To reveal the patterns of molding high-speed elements from stamped and spin formed liners, the action of shaped charges comprised of steel or copper segmental liners of small bending, was simulated numerically using the apparatus of continuum mechanics. The influence of the liner manufacture method was taken into account by varying the values of the physical and mechanical characteristics of the liner material. The design parameters of the simulated charge, with the exception of the liner bending, during the calculation study remained unchanged and corresponded to the parameters of the currently used samples. Following the numerical experiments results, the study shows that the elements molded from spin formed liners are less likely to become fractured while being formed and are also more integral (continuous) in comparison to the elements molded from stamped shaped charge liners.

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