Structural models of hybrid fiber composites orthogonally reinforced in the plane are constructed. They allow one to calculate the yield loci taking into account the plane stress state in all composition components with different tensile and compressive yield stresses. Materials of the components are homogeneous and isotropic, and their mechanical behavior is described by the associated flow rule for

The role of fiber reinforcement architecture in adjusting the mechanical properties of glass-fiber-reinforced epoxy composite materials is studied. Fibrous E-glass unidirectional (UD) and 3-dimensional (3D) samples with an identical fiber volume fraction were prepared. The UD composites displayed excellent properties along the fiber direction, but the 3D ones showed excellent properties in all three

The static performance of a composite type 4 CNG cylinder was investigated using a finite-element simulation and experimental validation. This cylinder involved a liner hoop wrapped with a fiber impregnated by a suitable resin. Tensile tests were performed on standard specimens to examine the mechanical properties of the composite material. Next, a finite-element simulation was performed to determine

In a geometrically linear formulation based on the use of variational principles of elasticity theory and the generalized Galerkin method, three approaches to constructing equations of static bending of orthotropic plates with a constant thickness are considered. The displacements of plate points are approximated by polynomials in the transverse coordinate with unknown coefficients of expansion. The

The impact behavior of hybrid composite plates cured at 120°C were examined by dropping weights on them for three hours. Two groups of hybrid composite plates were considered. In the first group (TYPE1), all plies were staked symmetrically or antisymmetrically with orientation angle 0°, but in the second group (TYPE2), plies were staked symmetrically or antisymmetrically with orientation angles 0°

The effect of nanosize alumina (Al2O3) concentration on the morphology and mechanical properties of microfibrillar composites obtained by processing the thermodynamically incompatible polypropylene/ copolyamide (PP/CPA) blend was studied. It was established that composite monofilaments exhibited a selfreinforcing effect due to the in situ formation of PP fibrils (microfibers) in the CPA matrix. The

Drop-weight tests were conducted to investigate the impact responses of carbon-fiber-reinforced composite laminates under low-velocity impacts. A finite-element model is proposed to describe the failure during impacts. The impact damage behavior of composite laminates with different thicknesses were simulated to analyze their energy absorption ability, and a method for its prediction is presented.

Results of experimental investigations into a unidirectional composite of basalt fibers and epoxy resin used as part of high-voltage electric wires are presented. Tensile tests of BFRP specimens previously held wrapped around a transportation drum during 10 h were carried out. The influence of the keeping time of the BFRP core in the composition of a high-voltage electric wire on drums of diameter

Experimental results are presented on the onset and propagation of local delaminations caused by the interaction between specimen edges and intralaminar cracks in fiber bundles of 90° layers in quasi-isotropic [–45/90/45/0]s CF/EP noncrimp fabric (NCF) laminates subjected to tension-tension fatigue loadings. It is confirmed that the first damage mode is intralaminar cracking in 90° layers, which consists

For the first time, the influence of microwave radiation on the structure of a three-dimensionally cross-linked, plasticized, filled polymer composite material based on low-molecular rubbers — a polydivinyl epoxyurethane rubber of grade PDI-3B and a divinyl rubber of brand SKD-KTR — was investigated. It is shown that variations in the mechanical characteristics of the composite material during irradiation

The effects of metakaolin (MK) and basalt fiber (BF) on the performance of gypsum-based composites were investigated. BFs 6 and 12 mm long were used in concentrations of up to 0.8 wt.%. Mechanical tests were conducted on both dry and water-saturated specimens. It was found that their flexural and compressive strengths increased with content of BFs to 0.6%. However, the mechanical and durability properties

The conventional wood-based composites contain an unreacted free formaldehyde, which causes a cancerous effect on humans. To overcome this problem, citric-acid-modified corn and oil palm starches are proposed as ecobinders for wood-based composites in this study. Experimental rubber-wood panels were made using the ecobinders. The panels were subjected to FT-IR, TGA, DSC, and X-ray diffraction analyses

Various composite materials used as biomaterials were tested by 20-, 50-, and 80-N chewing forces in distilled water and a poppy seed medium by using a computer-controlled chewing simulation procedure. In each chewing test, steatite balls 6 mm in diameter were used as an antagonist material. The mean volume loss of worn surfaces and the surface roughness of the composite materials was measured with

A finite-element (FE) model simulating the elastic behavior of anisotropic glass/epoxy composite laminates subjected to a biaxial tensile loading is proposed. A progressive failure prediction and analysis are performed in the ABAQUS FE code by using user-defined constitutive equations. A numerical analysis is performed for different loading ratios and ply angles. Gradual failure patterns of fiber and

The classical methods of surface damping of bending vibrations of thin-walled structures and a promising integrated version with a damping coating consisting of two layers of a material with pronounced viscoelastic properties and an intermediate thin reinforcing layer of a high-modulus material are discussed. A four-layer finite element for an elongate plate with an integral damping coating is developed

The results of studies into the influence of the thickness of a polystyrene shell applied to surfaces of dispersed corundum (Al2O3) filler particles on the structure and mechanical properties of the composition of an acrylonitrile butadiene styrene plastic are presented. It is shown that the mechanical properties of the composition depend at least on two factors: the interaction between shell molecules

An acoustic method for a quantitative assessment of the volume content of a polymeric matrix in CFRPs is proposed and realized experimentally. For this purpose, a laser-ultrasonic method based on the thermo-optical excitation of broadband pulses of longitudinal acoustic waves is used. A formula for calculating the volume content of the polymeric matrix in a CFRP from experimentally measured phase velocities

In this work, transmission electron microscopy (TEM) and Raman spectroscopy were used to assess the dispersion quality of carbon nanotubes (CNTs) in an epoxy matrix. Its ultimate tensile strength (UTS), engineering strain, local strain, and the elastic tensile modulus were determined experimentally. The effect of CNT sonication time in an ethanol medium was also evaluated. A statistical analysis using

Commercial γ − Al2O3 particles, Al2O3 n, and synthesized Al2O3 doped with iron oxide (Al2O3 Fe) were used as reinforcements to enhance the toughness of an unsaturated polyester resin (UPR). Alumina modification with vinyl, Al2O3 (n, Fe)–VT, and methacryloyl, Al2O3 (n, Fe)–ME functionalities contributed to the increase in the extent of covalent binding at the UPR/filler interface. Tensile tests showed