International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

Composite materials based on regenerated thermoplastics of the polyolefin class with high parameters of stress-strain characteristics, which are highly resistant to open flame and combustion, have been developed. A synergistic effect was achieved by introducing a complex of modifiers into the matrix polymer, including regenerated particles of polytetrafluoroethylene, positioned as ultrafine particles (UPTFE), and residual products of the production of phosphate fertilizers – phosphogypsum (PG). The developed composite materials, processed by injection molding, make it possible to manufacture elements of metal-polymer rollers of belt conveyors used in the mining industry.

A financial project has been prepared for the construction of a plant equipped with a technological line for the production of foam glass products. It is planned to build a warehouse for raw materials, a sector for preparation of materials, various production workshops for the manufacturing of foamed granules and pieces, a continuous tape or block of foam glass, various composite materials (thermal insulation and color decorative panels, various small and large composite elements, etc.), repair section and two warehouses for finished products. Approximate calculations have been made for the necessary raw materials, technical equipment, electricity, personnel and other costs for the realization and operation of the plant.

The research of the technology of obtaining new copper-ferrochrome composite material has been done. The results of its structure and properties analysis are presented. The material structure consists of the copper base, non-dissolved coarse inclusions of ferrochrome, diffused zones, forming around these inclusions and phases, having formed in the place of completely dissolved inclusions of ferrochrome fine particles. The material has good mechanical properties and a high wear resistance due to the formed solid solutions of the carbides in the copper.

Research on composite materials is nowadays developed on a global scale, because they have multipurpose applications. Composite materials are used in a wide range of industries. The most significant advantages of composite materials include st rength, stiffness, low fibre density (e.g. carbon fibre or glass fibre), the ability to make them into any shape required for the application. The paper deals with the possibilities of joining composite materials with metallic materials. The experimental part includes tests of the strength of the chosen type of adhesive and comparison of the individual results obtained by the experiment.

Design of high-voltage insulators with a capacity of 12 kV and 24 kV according to standard specifications and determination of the mechanical properties in virtual environment, as well as verification and validation of the results in laboratory conditions was the aim of this paper. The composition of the insulators was 50 vol. % epoxy resin and 50 vol. % SiO2. Based on the physical and mechanical parameters of high-voltage insulators, 3D models were generated to correlate with them. Virtual simulations of the optimized models were performed by using SolidWorks software based on Finite Element Method. In order to re-examine the results, laboratory tests on physical specimens for determination of tensile, compression and three-point bending strength were conducted. The simulations were positively verified and gave promising results. The research conclusions show that the simulations in virtual environment provide easier and faster design and development of high-voltage  insulators, which is of great importance for power transmission network industry.

The aim of this research it was the installation of a discharge sea water pipeline DN 1600 of GRP (glass-reinforced plastic) material in Vlore Bay. The analysis of the sinking of the pipe string has been carried out by using CAESAR II software and considering different load cases. The calculation was carried out for static condition (sustained load) and transient condition (occasional load). In consideration were taken the allowable stress due to bending for pipe and allowable stress for joint subjected to freezing. From the calculation it was evident that the most critical effect on the GRP pipe has done by the position of Concentrated Force due to the presence of sledge (approx.. 2 tons), not disassembled from the string after moving in the position from the shore. In these cases, where the central crane has been maintained fixed or moved downward, the maximum bending stress on the pipe was 12.03 MPa. According to the verification carried out for pipe wall in the transient condition (occasional load) the stability was good and for the joint, was shown, in the worst scenario, a bending stress 158% of the allowable one. In this case it is possible to have the crack of the resin used for the freezing of the joint but not the failure of the system joint + pipe that can withstand without, failure, a stress 3 times greater than the allowable stress for pipe according to EN1796.

The advantages of using composite materials are currently manifested in various industries. This creates space for their even greater application in the automotive industry. Car manufacturers strive to constantly reduce the weight of the car, increasing its durability and safety at the same time. Car consumption and associated emissions are closely monitored. Composite materials therefore offer a range of properties that meet today’s automotive requirements to a large extent.

The aim of this research it was the installation of an intake sea water GRP (glass-reinforced plastic) structure in Vlore Bay. A detailed study about the extreme wave condition offshore was carried out by the SWAN (Simulating Waves Nearshore) model. Then the mechanical structure stability calculation was performed with AxisVM8, a finite element modeler & solver. Conservative hypothesis were taken, such as to use the max static pressure value as per energy balance calculation on the sea waves. The program Fluid Flow was used to model the pipe line end with pipe chimney connections. The scope of the calculation was primarily to balance fluid flows in each chimney in order to match the range of 0, 2 – 0, 25 m/s velocity at each chimney entrance. The result of the mechanical and hydraulically stability verification for the sea water intake structure take in consideration it was positive and this structure was installed successfully.

The paper considers the impact of functionalized nanosized carbon particles on the physicomechanical characteristics of composite materials based on polyamides. The concentration of the modifier varied both in the field of “doping” concentrations and in the field of concentrations used in the industrial production of nanocomposite materials based on polymer matrices. It was found that the use of cryogenic treatment of the initial polyamide leads to an increase in physical and mechanical characteristics. The introduction of nanodispersed particles in the field of “doping” concentrations increases the strength and hardness of the developed compositions based on a polyamide matrix.

In the given work the influence of detonation carbon on a complex of strain-strength parameters and supramolecular structures of standard compositions based on natural rubbers without stearin acid has been investigates.

In the present work the distribution of ND in standard mixtures of natural rubber without the use of stearin acid was studied.

A brief analysis of studies in field of metal-matrix composite (MMC) materials production with use of pulsed-discharge technology (PDT) is performed in present paper. It is shown that high voltage electric discharge (HVED) in liquid allows obtaining homogeneous highly disperse blend of complex chemical composition. Consolidation of blend by method of spark-plasma sintering (SPS) ensures preservation of grain size, which allows achieving high strength characteristics of MMC.