The Design Algorithm of the Optimum Structure from the Elasticity Module Point of View for Composite Materials

The aim of this work is to compare from an experimental point of view the determination of in-plane shear strength of unidirectional composite materials by means of two off-axis tests: three-point flexure and tensile. In the case of the off-axis three-point flexure test, the condition of small displacements and the condition of lift-off between the specimen and the fixture supports have been taken into account. Some considerations regarding stress and displacement fields are presented. The in-plane shear characterization has been performed on a carbon fiber reinforced unidirectional laminate with several fiber orientation angles: 10°, 20°, 30°, and 45°. Test conditions for both off-axis experimental methods, in order to ensure their applicability, are presented. Off-axis flexure test is considered more suitable than off-axis tensile test for the determination of in-plane shear strength.

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Effect of Thermal Treatment of Birch Wood by Saturated Water Vapor on Granulometric Composition of Chips from Sawing and Milling Processes from the Point of View of Its Processing to Composites

Applied Sciences ◽

10.3390/app10217545 ◽

2020 ◽

Vol 10 (21) ◽

pp. 7545 ◽

Cited By ~ 1

Author(s):

Richard Kminiak ◽

Kazimierz A. Orlowski ◽

Ladislav Dzurenda ◽

Daniel Chuchala ◽

Adrián Banski

Keyword(s):

Composite Materials ◽

Milling Process ◽

Point Of View ◽

Cnc Machining ◽

Three Dimensions ◽

Raw Material ◽

Saturated Steam ◽

Birch Wood ◽

Environmental Criteria ◽

The Impact

The goal of this work is to investigate the impact of thermal modification of birch wood with saturated steam on the particle size distribution of the sawing and milling process. Birch wood (Betula pendula Roth) is an excellent source to produce plywood boards. Wastes from mechanical processing of birch wood are suitable to produce composite materials. Granulometric analyses of chips from sawing processes on the PRW 15M frame saw, as well as on the 5-axis CNC machining centre SCM TECH Z5 and the 5-axis CNC machining centre AX320 Pinnacle, proved that more than 95% of chips are chips of coarse and medium coarse chip fractions with dimensions above 0.125 mm. Depending on the shape, coarse and medium-thick chips belong to the group of fiber chips, the length of which is several times greater than the width and thickness. Fine fractions with dimensions smaller than 125 μm are isometric chips that are approximately the same size in all three dimensions. Thoracic dust fractions below 30 μm were not measured. The performed analyses showed that the heat treatment of birch wood with saturated steam did not affect the grain size of chips formed in sawing and milling processes on CNC machining centre and can be used as a raw material for the production of composite materials. Fabric filters are suitable for separating chips extracted from frame saws, PRW-15M or machining centre. Environmental criteria for the separation of chips from transport air in textile filters are met by filters with a fabric classified in class G4.

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Friction and Wearing Behaviour of Sintered Composites Made from Copper Mixed with Carbon Fibers

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.660.81 ◽

2015 ◽

Vol 660 ◽

pp. 81-85 ◽

Cited By ~ 1

Author(s):

Radu Caliman

Keyword(s):

Thermal Conductivity ◽

Thermal Expansion ◽

Composite Materials ◽

Friction Coefficient ◽

Carbon Fiber ◽

Carbon Fibers ◽

Coefficient Of Thermal Expansion ◽

Density Ratio ◽

Point Of View ◽

Short Carbon

This paper presents a study regarding friction and wear comportment of sintered composite materials obtained by mixture of copper with short carbon fibers. Sintered composites are gaining importance because the reinforcement serves to reduce the coefficient of thermal expansion and increase the strength and modulus. In case of composites form by carbon fiber and copper, the thermal conductivity can also be enhanced. The combination of low thermal expansion and high thermal conductivity makes them very attractive for electronic packaging. Besides good thermal properties, their low density makes them particularly desirable for aerospace electronics and orbiting space structures. Compared to the metal itself, a carbon fiber-copper composite is characterized by a higher strength-to-density ratio, a higher modulus-to-density ratio, better fatigue resistance, better high-temperature mechanical properties and better wear resistance. Varying the percentage of short carbon fibers from 7,8% to 2,4%, and the percentage of copper from 92,2% to 97,6%, five dissimilar composite materials have been made and tested from the wear point of view. Friction tests are carried out, at room temperature, in dry conditions, on a pin-on-disc machine. The friction coefficient was measured using abrasive discs made from steel 4340 having the average hardness of 40 HRC, and sliding velocity of 0,6 m/sec. The primary goal of this study work it was to distinguish a mixture of materials with enhanced friction and wearing behaviour. The load applied on the specimen during the tests, is playing a very important role regarding friction coefficient and also the wearing speed.

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Nanometric SiC influence on tribological properties of phenolic composite materials

INCAS BULLETIN ◽

10.13111/2066-8201.2021.13.1.14 ◽

2021 ◽

Vol 13 (1) ◽

pp. 131-140

Author(s):

George PELIN

Keyword(s):

Composite Materials ◽

Phenolic Resin ◽

Point Of View ◽

The Other ◽

Two Dimensional ◽

Carbon Felt ◽

Different Types ◽

The Coefficient Of Friction ◽

Laminated Materials ◽

Phenolic Composite

This paper presents an experimental study of the influence of nano metric silicon carbide in the composition of phenolic composites on the coefficient of friction. The paper is divided into three distinct parts investigating from a tribological point of view three different types of composite materials based on phenolic resin with three concentrations of nSiC (0.5; 1 and 2% by mass). In the first part, a comparative study of the behavior of phenolic resin was performed, representing the basis for the development of composite materials. In the second part, a study was performed on laminated materials reinforced with two-dimensional fabrics (glass fiber and carbon fiber, respectively). The last part studied two types of ablative phenolic materials based on micronic cork, on one hand, and on carbon felt on the other hand.

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Theoretical justification of the influence of change of dilaton and compression bonds of atoms of materials of machine parts on their tribological effect

PROBLEMS OF TRIBOLOGY ◽

10.31891/2079-1372-2021-100-2-71-78 ◽

2021 ◽

Vol 100 (2) ◽

pp. 71-78

Author(s):

V. Aulin ◽

◽

S. Lysenko ◽

A. Hrinkiv ◽

О. Derkach ◽

...

Keyword(s):

Composite Materials ◽

Friction And Wear ◽

Composite Coatings ◽

Point Of View ◽

Solid State Physics ◽

Surface Layers ◽

Theoretical Justification ◽

Friction Zone ◽

Machine Parts ◽

Bulk Content

The course of friction and wear processes in the surface layers of conjugations of machine parts is clarified on the basis of the idea of dilaton and compression bonds of atoms in the materials of parts. Dilaton-compression connections are random in nature, and therefore in this work the theory of destruction of parts by S.M. Zhurkov, thermodynamic and quantum physical approaches. The entropy at the macro-, meso- and microscopic levels and the local regions of the materials of conjugation of the parts subject to friction loading are considered. In the diagram of the state of atomic-molecular bonds the dependence curve Fi(ri) or Ti(ri) is considered and the analysis of transformations of bonds according to the specified diagram is carried out. From the point of view of solid state physics and tribophysics, the manifestation, evolution and consequences of the influence on the characteristics and properties of the friction zone of dilaton and compression bonds of material atoms are considered. Composite materials (composite coatings) are substantiated in more detail. This takes into account the assessment of the concept of material stresses in the friction zone, the ability to relax it, as well as the presence of the SD effect. The fracture process is associated with the modulus of elasticity of the components of the composite material and the bulk content of the filler. An appropriate condition is proposed, which determines the tribological efficiency of composite materials and coatings.

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Application of New Design Method by High-Strength Composite Material

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.607.915 ◽

2014 ◽

Vol 607 ◽

pp. 915-919 ◽

Cited By ~ 1

Author(s):

Haruhiko Iida ◽

Toshiaki Fujishima ◽

Yoshifumi Ohbuchi ◽

Hidetoshi Sakamoto

Keyword(s):

Composite Materials ◽

Product Design ◽

Design Method ◽

High Strength ◽

New Product ◽

Point Of View ◽

Light Weight ◽

Fiber Reinforced Plastic ◽

Reinforced Plastic ◽

Separate Product

The purpose of this study is to apply a new design method, which integrates both optimum strength and product design. Here, the collaboration of design and strength by using composite materials is administered. Many products, which are made from high strength composite materials, require new product design technology. Existing product developments tend to separate product design from product planning. The process begins from planning the shape of the product, then calculating the strength, and lastly designing the product. In our new design method, we create from an engineering point of view. By using a design method of high-strength materials, we designed a new ZIGZAG CHAIR made of carbon fiber reinforced plastic of excellent strength and light-weight.

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Vibration Analysis of Thin/Thick, Composites/Metallic Spinning Cylindrical Shells by Refined Beam Models

Journal of Vibration and Acoustics ◽

10.1115/1.4029688 ◽

2015 ◽

Vol 137 (3) ◽

Cited By ~ 19

Author(s):

E. Carrera ◽

M. Filippi

Keyword(s):

Composite Materials ◽

Initial Stress ◽

Cylindrical Shells ◽

Three Dimensional ◽

Point Of View ◽

Displacement Fields ◽

Previous Theory ◽

Cross Sectional ◽

Computational Point ◽

Thick Composites

This paper evaluates the vibration characteristics of thin/thick rotating cylindrical shells made of metallic and composite materials. A previous theory of the authors is extended here to include the effects of geometrical stiffness due to rotation. To this end, variable kinematic one-dimensional (1D) models obtained by applying the Carrera Unified Formulation (CUF) were used. The components of the displacement fields are x, z polynomials of arbitrary order N, making it possible to go beyond the rigid cross section assumptions of the classical beam theories. A significant contribution of this formulation consists in the possibility to include the in-plane cross-sectional deformations allowing the introduction of the in-plane initial stress effects, e.g., the effect of the geometrical stiffness. Equations of motions, including both Coriolis and in-plane initial stress contributions, were solved through the finite element method. Several analyses were carried out on both thin and thick cylinders made of either metallic or composite materials with different boundary conditions. The results are compared with analytical and numerical shell formulations and three-dimensional solutions available in the literature. Various laminate lay-up have been considered in the case of composites shells. Numerical evaluations of the effect of geometric stiffness are provided, demonstrating its importance in the analyses presented. The 1D models appear very effective to investigate the dynamics of spinning shells and, contrary to shell theories, they do not require any amendments with thick shell geometry. From the computational point of view, the present refined beam models are less expensive than the shell and solid counterparts.

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Analysis of Composite Materials—A Survey

Journal of Applied Mechanics ◽

10.1115/1.3167081 ◽

1983 ◽

Vol 50 (3) ◽

pp. 481-505 ◽

Cited By ~ 1683

Author(s):

Z. Hashin

Keyword(s):

Thermal Expansion ◽

Composite Materials ◽

Fatigue Failure ◽

Static Strength ◽

Point Of View ◽

Engineering Science ◽

Applied Mechanics ◽

Present Survey ◽

And Diffusion ◽

Mathematical Analogy

The purpose of the present survey is to review the analysis of composite materials from the applied mechanics and engineering science point of view. The subjects under consideration will be analysis of the following properties of various kinds of composite materials: elasticity, thermal expansion, moisture swelling, viscoelasticity, conductivity (which includes, by mathematical analogy, dielectrics, magnetics, and diffusion) static strength, and fatigue failure.

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TECHNOLOGICAL ASPECTS OF PRODUCTION AND RESEARCH OF POLYMERS COMPOSITE MATERIALS WITH INCREASED STRENGTH

IZVESTIYA VYSSHIKH UCHEBNYKH ZAVEDENIY KHIMIYA KHIMICHESKAYA TEKHNOLOGIYA ◽

10.6060/tcct.20176010.5638 ◽

2017 ◽

Vol 60 (10) ◽

pp. 82

Author(s):

Rena E. Mustafaeva

Keyword(s):

Composite Materials ◽

Elevated Temperatures ◽

Raw Materials ◽

Low Cost ◽

Point Of View ◽

Atactic Polypropylene ◽

Rubber Compounds ◽

Increased Strength ◽

Tearing Resistance ◽

Constant Deformation

The work is devoted to the search for new effective modifying additives that allow to purposefully regulate the technological properties of rubber compounds and physical-mechanical properties of rubbers based on combinations of non-polar rubbers and at the same time being cheaper and more affordable than traditional products, in particular, with resorcinol-urotropin complex (modifier RU -1). It was proposed to use as a modifier of frame rubbers based on a combination of isoprene (SKI-3) and butadiene-styrene (SCS-30ARKM-15) rubbers, chlorinated atactic polypropylene (CHAPP). It is shown that when the RU-1 modifier is replaced with this compound, the conditional stresses and tensile strength, tearing resistance, rebound elasticity, fatigue resistance in the regime of constant deformation amplitude, heat resistance, resistance to thermal aging of rubbers, as well as the strength of rubber bonding with rubber Textile cord, including at elevated temperatures are observed. Comparison of the CHAPP for the effectiveness of the action in the carcass gum with the previously proposed oligoefirmetacrylate epichlorhydrine, from the point of view of the provided complex of properties, showed the advantage of chlorinated atactic polypropylene for a number of priority indicators. From the comparative analysis of the modifying activity of chlorinated atactic polypropylene and oligoether methacrylate epichlorohydrin, it follows that the vulcanizates of rubber compounds containing instead of RU-1 chlorinated atactic polypropylene CHAPP are characterized by more improved parameters of hardness in TM-2, elasticity by rebound, the strength of the rubber-cord connection. It is also revealed that the main advantage of the proposed modifier is the low cost of the modifier used, as well as the use of secondary raw materials for its production.Forcitation:Mustafayeva R.E. Technological aspects of production and research of polymers composite materials with increased strength. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2017. V. 60. N 10. P. 82-86

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Design of the Cemented Doublet – Software Application

Robotica & Management ◽

10.24193/rm.2021.1.3 ◽

2021 ◽

Vol 26 (1) ◽

pp. 13-16

Author(s):

Luiza Sonia Oprean ◽

Corina-Mihaela Gruescu

Keyword(s):

Optical System ◽

System Analysis ◽

Point Of View ◽

Design Algorithm ◽

Software Application ◽

Imaging Application

From optical point of view, an imaging application includes the sensor (CCD or CMOS) and the objective. The simplest objective consists of a cemented doublet. The paper proposes a design algorithm of the doublet and describes a software application based on this algorithm. The results provided by the original software are validated by means of a professional application in optical system analysis.

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