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The assets that are normally accessible in the climate are the keys to the improvement of material science. The utilization of assets as materials is expanding every day for the endurance of humanity which likewise impacts the eco-framework as a boundary. From the development use of the materials, composites assume a fundamental part that is liable for the new speculations, advancements, and applications in various areas of science. As to convey forward the advancement in material science, the quest for elective utilization of engineered or counterfeit polymer composites which are non - degradable is begun because their temperament impacts the supportability, and balance in the climate whichstraightforwardly impacts the everyday routine pattern of experiencing creatures in nature. Subsequently, the way leads to regular composite materials which are bio-degradable and eco-accommodating to the climate. The recuperating capacity peculiarities themselves exist in nature, whichis adjusted to the material science field to build the existence use of the material. Self-composites appeared and were created by numerous analysts and its system and various kinds of approaches are given out exhaustively. In any case, the greater part of one self-healing idea was finished and given out on engineered composite materials. This displayed as an exploration hole and drove us to research the impact of the self-recuperating ideaon regular fiber-supported green composites. This paper gives out a concise viewpoint hypothesis on self-healing composites. [ABSTRACT FROM AUTHOR]

The northern regions characterized by harsh climatic conditions should be developed using modern technology employing polymeric materials suitable for use at temperatures down to -60 °C. The creation of polymer composite materials based on polytetrafluoroethylene (PTFE) with highly perfected service characteristics is one of the priority tasks of modern materials science. The paper discusses the physical-mechanical, tribological, and thermodynamic properties of composites based on PTFE and various types of fillers. The results of the study show that complex filling in a certain combination provides a high degree of interaction between the polymer and the filler, thereby significantly improving the properties of PTFE-based composites. [ABSTRACT FROM AUTHOR]

In this paper, we propose an algorithm for predicting the residual life of structures made of polymer composite materials (PCM) using a structured phenomenological model. In the developed algorithm for estimating the residual life of PCM structures under cyclic loading, it is proposed to use the explicit description of the process of destruction of adhesive layers. The implementation of the algorithm is accomplished in the APDL language in ANSYS Mechanical. The algorithm and the program are tested on a flange type design. Based on the results of numerical experiments, the area of damage is identified. The service life is determined, as well as the allowable value of the PCM flange stiffness drop under cyclic loading. [ABSTRACT FROM AUTHOR]

Residual stress in layered composites significantly affects their mechanical properties. One of the most important tasks in the sphere of experimental mechanics is the development of effective methods for the accurate determination of residual stress values. This paper describes a modified destructive testing method implemented through layer-by-layer stitching. It differs from previous analogous methods by the use of electronic speckle pattern interferometry to measure the deformation response of a given sample. The interpretation of the initial experimental data in “stress terms” was carried out based on modeling through the use of the finite element method (FEM). [ABSTRACT FROM AUTHOR]

In contrast with neat polymers, filled polymeric composites of ultrahigh molecular weight polyethylene (UHMWPE) are certainly more efficient in manufacturing industrial products (for instance, when reinforcing fibers are loaded). An experimental-theoretical technique for designing a polymer composite with specified properties is discussed in the paper. An approach to determine control parameters (phase composition, physical and mechanical properties, etc.) in order to design a composite with prescribed effective properties or providing them within a predetermined range is proposed. With the use of the approach based on the experimental data analysis in concern of effective characteristics versus the values of the control parameters, corresponding response surfaces of the physical-mechanical characteristics are constructed in the space of states. This allows one to determine the correct and reachable values of the control parameters. The calculated response surfaces make it possible to reveal the range of values of control parameters for specified characteristics of multicomponent reinforced extrudable UHMWPE polymer composites. [ABSTRACT FROM AUTHOR]

The paper presents research results on the properties of polymer composite materials based on ultrahigh molecular weight polyethylene and polytetrafluoroethylene modified with carbon fibers. It has been established that an increase in CF concentration is accompanied by a decrease in the stress-strain properties of a PCM based on PTFE, as well as by a change in the behavior of tensile strain curves of the PCM. It has been found that the decrease in stress-strain properties and the change in the failure mode of PTFE-based composites containing CF of the LO-1-12N/40 grade occur at a concentration of 5 wt%, and with the introduction of fibers of the Belum brand, 10 wt% concentration is required. This is probably due to the different values of the critical volume content (φm) of CF in PTFE. It has been detected that the strength is increased by 80% at 5% compression of PCM, and it is doubled at 10% compression in comparison with unfilled PTFE. The rate of mass wear of the PCM based on PTFE containing discrete carbon fibers decreases with an increase in filler concentration. The prospects of using carbon fibers as a reinforcing element of UHMWPE with the aim of obtaining new composites with high tribotechnical characteristics intended for operation under conditions of limited lubrication or dry friction are shown. It has been established that, to improve the stress-strain properties and wear resistance of the PCM based on UHMWPE, it is efficient to use carbon fiber of the Belum brand as a filler, since the interphase interaction of UHMWPE with the fiber is strong due to a hydrophobic fluoroorganic coating on the surface of these carbon fibers. [ABSTRACT FROM AUTHOR]

This paper analyses the progressive failure of a variable-stiffness composite structure (VSCS). The composite structure is simulated by means of a design method developed earlier. The design method allows curvilinear fibers to be adapted to various geometric discontinuities (holes, notches, etc.) or non-uniform loading. The fiber orientation and fiber volume fraction are heterogeneous in the VSCS. To model progressive failure, a material property degradation method (MPDM) is used. The properties of the composite structure are locally changed due to the nonuniformity in the fiber volume fraction, and the change of the properties is taken into account in the MPDM. A rectangular plate with a hole under tensile loading is modeled, and it is shown that use of the VSCS is more effective than the use of a composite structure with rectilinear reinforcement (orthotropic material) under identical conditions. [ABSTRACT FROM AUTHOR]

The paper presents first results of obtaining metal-matrix composites based on severe plastic deformation by shear under pressure of layered Al and Cu components. Three-layer composites with different alternation of layers, i.e. Al-Cu-Al and Cu-Al-Cu, were processed by constrained high pressure torsion to produce monolithic disk-shaped samples without pores. Analysis of the macroscopic homogeneity showed that different alternation of layers led to varying degrees of mixing of the starting components. [ABSTRACT FROM AUTHOR]

The paper considers the elastic properties of epoxy composites reinforced by 6 types of silica nanoparticles with different average diameter at the same weight concentration of 1.1%. The addition of silicon nanopowders increases the modulus of elasticity. For powders of the same origin, with an increase of the modulus of elasticity, a decrease in the characteristic diameter of the filler particles at a constant concentration is observed. It is shown that the characteristic average particle size is not the only factor determining the growth of the elastic modulus, since the growth of the modulus is significantly different for powders of different producers. [ABSTRACT FROM AUTHOR]

This paper studies a new way of cladding particles by preliminary mechanical mixing of particles of a refractory material (TiN) with particles of a binding metal (Ti) followed by forming granules containing 20 mass fractions of initial particles of titanium nitride and their further processing in an argon-helium plasma jet in a controlled atmosphere. As a result of experimental studies, a composition powder consisting of spherical particles sized from 0.1 to 40 μm is obtained. The refractory nanoparticles of titanium nitride in it are evenly distributed over the volume of the binding metal (titanium) and completely plated by it. The surface morphology and the internal structure of the particles are studied, the results of X-ray phase analysis are presented, and a map of element distribution over both the surface and volume of the composition particle is obtained. This method of producing nanomodifying compositions helps to improve homogeneity of the distribution of refractory elements in the melt volume, as well as their wettability, which increases the effectiveness of modifying the material properties. [ABSTRACT FROM AUTHOR]

In this paper, an approach to solving the problem of the determination of effective stress-strain, thermophysical and electrophysical properties of filled composite materials on the basis of the variational principles is developed. In the numerical implementation, it might be reduced to the use of the finite element method (FEM). An approach, possessing a certain generality, to finding effective physical-mechanical, thermophysical and electrophysical properties of filled polymer composites is proposed and described. Firstly, a general concept based on obtaining detailed parameters of the composite state under external impact taking into account the actual structure of the material is developed. Then, the averaging procedure aimed at obtaining effective properties of the composites is employed. Secondly, the realization of boundary problems is reduced, for all cases (physical-mechanical, thermophysical and electrophysical), to the formulation of the corresponding variable principles and their realization by the methods of computational mechanics, in particular, by the finite element method. [ABSTRACT FROM AUTHOR]

The paper studies the structure, chemical and phase compositions and hardness of Fe-Ni-Ti-C-B composites produced by self-propagating high-temperature synthesis (SHS). It is demonstrated that, when Fe, Ni, Ti, C and B4C are used as initial materials in the form of a powder mixture poured into a steel pipe, a one-piece multilayer plate is formed under SHS, inside which there is a composite with a matrix of a solid solution of Fe in a γ-Ni lattice and reinforcing TiC, TiB2, and Fe2B particles with a hardness of 62 HRC. The inner surface of the steel shell is firmly joined to the composite due to the synthesis products diffusing into the steel. [ABSTRACT FROM AUTHOR]

Analysis of design methods for composite beams with curvilinear fiber trajectories is considered in this paper. The novelty of this approach is determined by the fact that traditional composite materials are typically formed using prepregs with rectilinear fibers only. The applications of the results are associated with designing shaped members with a composite structure by using of biomechanical principles [1,2]. One of the problems is evaluation of the effect of fiber misorientation on the stiffness and load carry capacity of a shaped composite element with curvilinear fiber trajectories. An equistrong beam with a constant cross-section area is considered as an example, and it can be produced by forming of a unidirectional fiber bunch impregnated by a polymer matrix. Methods for evaluating the effective elastic modulus for structures with curvilinear fiber trajectories are validated. The misorientation angle range (up to 5 degrees), when a material with required accuracy can be considered as homogeneous, is determined, fiber misorientation being neglected. It is shown that, for beams with a fairly small height-to-width ratio, it is possible to consider only 2D misorientation. [ABSTRACT FROM AUTHOR]

The machining of FRP composites has posed a serious challenge to industry and academia alike as far as the sub-surface damage is concerned caused by fiber-matrix debonding. Proper prediction of sub-surface damage is thus essential for different fiber orientations and fiber-matrix bonding. A Cohesive Zone Modeling (CZM) of the fiber-matrix debonding leading to interfacial separation is presented in this paper. The cohesive bonding strength existing between the fiber and matrix increases with increased separation, reaches a maximum value before causing permanent debonding when the cohesive strength between the interfaces vanishes. An effort is made to implement the Cohesive Zone Model (CZM) and to ascertain the extent of debonding below the trim plane at fiber failure. © 2004 American Institute of Physics [ABSTRACT FROM AUTHOR]

In this paper, statistical continuum mechanics modeling is applied to predict the elastic mechanical properties of an anisotropic Al-SiC composite. Two-point statistics are measured on vertical metallographic planes in three-dimensional microstructures. As a result of anisotropy the correlation functions are orientation dependent. Longitudinal and transverse elastic moduli are calculated for two samples with different PSR and clustering, and the results are compared with upper and lower bound and experimental data. It’s observed that the theoretical results are in good agreement with experimental data and two-point statistics significantly contribute to the estimation of the elastic modulus. © 2004 American Institute of Physics [ABSTRACT FROM AUTHOR]

Spatial and temporal limitations of atomistic simulations necessitate the development of multiscale methodologies that link atomic and continuum scales. In this paper, a hierarchical multiscale model is presented to study the thermomechanical behavior of carbon nanotube (CNT) based composites. The method explicitly accounts for the behavior of nanoscale interfaces existing between the matrix and CNT. Molecular dynamics simulations based on Tersoff-Brenner potential are employed to study the interfaces in CNT based composites, while finite element method simulates macro behavior with the link provided by cohesive zone model parameters. The multiscale model is used to study the effect of interface strength on stiffness of the composite. © 2004 American Institute of Physics [ABSTRACT FROM AUTHOR]

In this paper a Voronoi Cell Finite Element (VCFEM) scheme is presented to model ductile damage in metal matrix composites (MMCs). Particle fracture and matrix cracking are used to model failure of the composite. Numerical examples for simple microstructures are used to validate the model. An example of an actual morphological description of a MMC is used illustrate the potential of the method. © 2004 American Institute of Physics [ABSTRACT FROM AUTHOR]

In sheet forming, the creation of wrinkles in the flange area of the blank commonly occurs. When diaphragm forming aligned-fiber-reinforced thermoplastic composites, observations reveal that the wrinkles tend to occur at angles oriented at forty-five degrees to the axis of the fibers. Intuition suggests that this is related to shear, but this may be misleading. The results of a stress-analysis and buckling analysis of this flange wrinkling problem are discussed. The forming of the thermoplastic sheets occurs at elevated temperatures and the sheet is essentially inextensible in the fiber direction. This leads to high anisotropy ratios of in-plane stiffness properties. The out-of-plane bending of the sheet will be strongly influenced by the presence of polymeric diaphragms. To investigate the buckling problem for this forming situation, a finite-difference formulation was developed. The solution revealed that only when one considers the combined effect of the thermoplastic composite and the polymeric diaphragms does the analysis predict the observed forty-five degree buckles. © 2004 American Institute of Physics [ABSTRACT FROM AUTHOR]