scholarly journals Determination of Young’s Moduli of the Phases of Composite Materials Reinforced with Longitudinal Fibers, by Global Measurements

Symmetry ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 1607
Author(s):  
Renata Ildikó Szavá ◽  
Ioan Szavá ◽  
Sorin Vlase ◽  
Arina Modrea
Keyword(s):  
Composite Material ◽  
Composite Materials ◽  
Constitutive Law ◽  
Engineering Practice ◽  
Phase Component ◽  
Young’S Moduli ◽  
Transverse Isotropic ◽  
Materials Used ◽  
Independent Parameters

The properties of a composite material are determined by the properties of the constitutive materials. In engineering practice, there are many situations in which we have composite material, but we do not have information about the properties of each phase component. The measurements we can make in such cases are on the existing material, thus being able to determine, experimentally, the global physical properties of the composite. The possibility of realizing an estimate of the mechanical properties of each component poses a problem if we start from these measurements. The paper proposes a method to achieve this, starting from the theoretical estimates established in the literature, then illustrated by an example to determine the properties of wood. Wood is a transverse isotropic material and therefore the constitutive law has symmetries that are manifested in the decrease of the number of parameters that define the stress-strain liason, defined only by five independent parameters. The proposed method can be extended to a diversity of models and materials used in the study of composite materials.

Research on Composite Materials Used for Brake Shoes Manufacture

2016 ◽  
Vol 254 ◽  
pp. 207-211 ◽  
Author(s):  
Erika Popa ◽  
Liviu Pascu ◽  
Ana Socalici ◽  
Marius Ardelean
Keyword(s):  
Composite Material ◽  
Cast Iron ◽  
Composite Materials ◽  
Carbon Fiber ◽  
Contact Zone ◽  
Laboratory Experiments ◽  
Rolling Stock ◽  
Brake Shoe ◽  
Materials Used

The paper relates laboratory experiments in order to obtain a composite material used for brake shoe manufacture. Regarding the testing materials were processed 38 samples. The percentage and composition of materials are: 15-45% novolac, 1,5-10% hexametyltetramin, 0-8% sulfur, 0-15% carbon fiber, 0-20% graphite, 0-25% aluminum, 15-28% brass and 0-40% rubber. The evolution of tribological and temperature parameters were analyzed in the contact zone tribological testing disk - split pin method. The composite material has the role to replace the classic material (cast iron) used in brake shoes composition in order to reduce the noise caused by rolling stock.

scholarly journals Laboratory studies of heated Bulk Fill composite in the tooth cavity during filling of teeth with carious defects

2021 ◽  
Vol 19 (4) ◽  
pp. 293-298
Author(s):  
V. A. Kriventseva ◽  
Y. B. Vorobieva ◽  
V. V. Nikitenko
Keyword(s):  
Composite Material ◽  
Composite Materials ◽  
Room Temperature ◽  
Laboratory Studies ◽  
Marginal Fit ◽  
Military Medical Academy ◽  
Medical Academy ◽  
Hard Tissues ◽  
The Russian Federation ◽  
Materials Used

Aim. To study with the help of a microscope the marginal fit of Bulk-Fill group composite materials to the hard tissues of the tooth. Optimize the method of heating the composite in the cavity.Materials and methods. The marginal fit of the composite material of the Bulk-Fill group, sealed in 30 teeth of chewing anatomical and functional accessories extracted according to various indications, was studied. Materials used in the laboratory experiment: 3M ESPE Filtek posterior restorative Bulk Fill, SDR (Dentsply Sirona), Sonic Fill (Kerr). According to the manufacturers, the materials are used with the method of single-portion sealing. The research was conducted at the Department of General Dentistry of the S.M.Kirov Military Medical Academy of the Ministry of Defense of the Russian Federation.Results. 30 teeth extracted according to various indications of chewing anatomical and functional accessories were indicators were shown by the Sonic Fill (Kerr) system, due to heating and changing the viscosity of the material.Conclusions. It was proved in the laboratory that the heated composites of the Bulk-Fill group had the best edge fit during sealing than composites at normal room temperature. A nozzle was developed for heating the composite in the tooth cavity (priority application No. 2021120658 dated 12.07.2021). 

Numerical modeling of the hygro-mechanical behavior of the 3D composite materials

2020 ◽  
Vol 54 (28) ◽  
pp. 4457-4471
Author(s):  
Mamadou Abdoul Mbacké ◽  
Shahram Khazaie ◽  
Sylvain Fréour ◽  
Frédéric Jacquemin
Keyword(s):  
Composite Materials ◽  
Moisture Content ◽  
Numerical Approach ◽  
Material Behavior ◽  
Constitutive Law ◽  
Mechanical Coupling ◽  
Finite Element Software ◽  
3D Composite ◽  
Materials Used ◽  
The One

The composite materials used in marine environments are subjected to mechanical loads along with the water absorption. The analysis of the behavior of such materials requires to take into account the coupling between the mechanical and diffusion behaviors. The hygro-mechanical coupling has been widely investigated experimentally and numerically. This paper presents a numerical approach to model the hygro-mechanical coupling of composite materials. The diffusion process is modeled via the classical Fick’s law. The elasticity matrix is considered to belong to transverse isotropic class, i.e. the composite studied is a unidirectional one. The components of the former are considered as moisture content dependent. The constitutive law takes into account on the one hand the strain induced by the hygroscopic swelling and on the other hand the dependence of the mechanical properties (elastic constants along with the material ultimate strengths) on the moisture content. These are implemented in a finite element software used to investigate the influence of the hygro-mechanical coupling on the composite material behavior. The robustness of our numerical tool is investigated with some numerical case studies.

Study on Composite Materials Used in the Tennis Racket

2014 ◽  
Vol 540 ◽  
pp. 52-55
Author(s):  
Tie Huan Sun
Keyword(s):  
Composite Material ◽  
Composite Materials ◽  
Production Process ◽  
Process Analysis ◽  
Tennis Player ◽  
Process Performance ◽  
Tennis Racket ◽  
Good Pair ◽  
Materials Used ◽  
Important Position

In many sports, tennis occupies an important position. For a tennis player, it is an important factor in a good pair of tennis to win the game. The composite materials in the production process in tennis racket are studies in this paper. Analyzed and demonstrated several ways from its function and structure, process performance, process and process analysis. Finally, the production process of the racket will be detailed study, and then a conclusion will be get that is composite material has important practical value in the production of a tennis racket.

scholarly journals Intermediate Scale Composite Material Fire Testing

2011 ◽  
Author(s):  
Alexander L. Brown ◽  
Amanda B. Dodd ◽  
Brent M. Pickett
Keyword(s):  
Composite Material ◽  
Composite Materials ◽  
Intermediate Scale ◽  
Thermal Environments ◽  
Fire Environment ◽  
Chemical Products ◽  
Materials Used ◽  
Thermal Intensity ◽  
In Fire ◽  
Carbon Fiber Epoxy

Composite materials are increasingly being used in aviation applications. As the quantity of composite material increases, there is a corresponding need to develop a better understanding of composite material response in fire environments. We have recently developed a program to examine this problem experimentally and computationally. Although Sandia National Laboratories and Air Force Research Laboratories at Tyndall have slightly different focuses, we are collaborating to focus on understanding duration, intensity, and the underlying physics during composite fires, as well as the technology and procedures to safely manage composite fire events. In the past year, we have been performing both small and intermediate scale testing to understand the behavior of composite materials used in aviation applications. The current focus is on a set of intermediate scale tests to generate data useful for understanding the behavior of carbon fiber epoxy composites in adverse thermal environments. A series of tests has been performed in a 90 cm cubic enclosure with 25–40 kg of composite materials to generate a severe fire environment fueled mostly by the composites. Preliminary results of these tests will be reported to provide data on the severity of the environment in terms of thermal intensity, duration, and chemical products.

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

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.

Models for Fibrous Composites With Different Properties in Tension and Compression

1977 ◽  
Vol 99 (4) ◽  
pp. 344-349 ◽  
Author(s):  
C. W. Bert
Keyword(s):  
Composite Material ◽  
Composite Materials ◽  
Mathematical Models ◽  
The Other ◽  
Reciprocal Relation ◽  
Angular Orientation ◽  
Compliance Matrix ◽  
Young’S Moduli ◽  
Elastic Composite ◽  
Tension And Compression

It has been observed that certain filamentary composite materials exhibit a different Poisson compliance when loaded transversely to the fibers than when loaded longitudinally (parallel to the fibers). In such cases the following widely used reciprocal relation is not satisfied: νLT/EL=νLT/ET where EL and ET are the L (longitudinal) and T (transverse) Young’s moduli and νLT and νTL are the Poisson’s ratios obtained from uniaxial loading in the L and T directions. Here two entirely different approaches are used to develop mathematical models of an elastic composite material behaving as described above. One method permits the compliance matrix to be unsymmetric but vary smoothly with the angular orientation. The other method, which is believed to be more valid, incorporates one set of symmetric compliances when the fibers are loaded in tension and a different set of symmetric compliances when the fibers are loaded in compression. The two different models are applied to some data for rubber reinforced by aramid (Kevlar) cord. For this composite, the above reciprocal relation is least satisfied, since νTL/ET is approximately 147 times νLT/EL.

scholarly journals Cable-stayed coverings for large-span public buildings

2021 ◽  
Vol 280 ◽  
pp. 07008
Author(s):  
Radomir Timchenko ◽  
Stanislav Popov ◽  
Dmitry Krishko ◽  
Goodary Rajeshwar ◽  
Aleksej Aniskin
Keyword(s):  
Composite Material ◽  
Composite Materials ◽  
Optimization Problem ◽  
Optimal Result ◽  
Large Span ◽  
Roof Structure ◽  
Standard Design ◽  
Design Characteristics ◽  
Selection Of

Structural schemes of coverings using lightweight roof structure from modern composite materials are investigated in this paper. A comparison of two options for cable-stayed covering of a circus auditorium, one with an orthogonal mesh of cables (according to a standard design) and another one, with a mesh of cables formed by two groups of stabilizing cables are considered. The possibilities of reinforcement with composite material are analyzed. Calculation and preliminary selection of cable-stayed sections are also carried out and presented. The variations of the conditional volume with the relative sag arrows, for varying values of the coefficient qk have been investigated and shown on graphs. An optimization problem was solved and the optimal result with detailed calculations are proposed and presented in this research which enable the design of the cable-stayed coating with determination of its design characteristics. As a result, the optimum and most economical sections of the cable-stayed covering were obtained. The calculations also show the inexpediency of using a heavy roof structure for saddle cable-stayed coverings due to the exclusion of stabilizing cables from the operation with a large roof weight.

scholarly journals Low-temperature tension properties of glass-epoxy composite materials

2005 ◽  
pp. 123-134
Author(s):  
Slavisa Putic ◽  
Marina Stamenovic ◽  
Branislav Bajceta ◽  
Predrag Stajcic ◽  
Srdjan Bosnjak
Keyword(s):  
Tensile Strength ◽  
Composite Material ◽  
Composite Materials ◽  
Room Temperature ◽  
Epoxy Composite ◽  
Epoxy Composites ◽  
Tension Properties ◽  
Different Temperatures ◽  
Stereo Microscope

The aim of this paper was to present the determination of tensile strength Rm and modulus of elasticity Et of glass-epoxy composites at two different temperatures (at room temperature t=20?C, and at t =?50?C). Standard mechanical testing was carried out on glass woven-epoxy composite material with different structures (two specific weights of reinforcement, 210 g/m2 and 550 g/m2) and orientations (0?/90? and ?45?). Micromechanical analysis of failure was performed on a stereo microscope and SEM in order to determine real models and mechanisms of crack.

Sign in / Sign up

Export Citation Format

Share Document