A Water Surface Contaminants Monitoring Method Based on Airborne Depth Reasoning

Water surface plastic pollution turns out to be a global issue, having aroused rising attention worldwide. How to monitor water surface plastic waste in real time and accurately collect and analyze the relevant numerical data has become a hotspot in water environment research. (1) Background: Over the past few years, unmanned aerial vehicles (UAVs) have been progressively adopted to conduct studies on the monitoring of water surface plastic waste. On the whole, the monitored data are stored in the UAVS to be subsequently retrieved and analyzed, thereby probably causing the loss of real-time information and hindering the whole monitoring process from being fully automated. (2) Methods: An investigation was conducted on the relationship, function and relevant mechanism between various types of plastic waste in the water surface system. On that basis, this study built a deep learning-based lightweight water surface plastic waste detection model, which was capable of automatically detecting and locating different water surface plastic waste. Moreover, a UAV platform-based edge computing architecture was built. (3) Results: The delay of return task data and UAV energy consumption were effectively reduced, and computing and network resources were optimally allocated. (4) Conclusions: The UAV platform based on airborne depth reasoning is expected to be the mainstream means of water environment monitoring in the future.

Assessment of a Heterogeneous Environment

An approach to the assessment of a heterogeneous environment in accordance with the proposed concept of a heterogeneous environment is described. The classification of industrial heterogeneous media by technological feature is proposed. The processes described by the proposed approach include the process of metal cutting, surface plastic deformation, chemical-thermal treatment, formation of coatings, welding, most of the processes that change the level and gradient of hardness and internal stresses in the surface layer of the material. Application of the proposed principles makes it possible to find new directions in the study of such processes.

Constructive and technological method of increasing durability of “choke connections”

Welded circular seams of “choke joints”, as a rule, have deviations from the specified diameter. This leads to uneven deformation, and sometimes to the absence of deformations in some areas of the seam. With repeated static loads, destruction arises in these places. To connect to the maintenance system of connections with the base metal, used as a guide, surface plastic deformation of the zone zone is carried out. A technology and equipment have been developed that allow plastically deforming the area of transition from the weld to the base metal along the entire length of the circular weld. As a result of plastic deformation along the technological groove, the characteristics of low-cycle fatigue of welded joints are obtained, which are not inferior to the base metal. To reduce stresses in the zone of transition from the weld to the base metal, it is proposed, first, to perform a circular groove on the base metal by machining, as close as possible to the specified zone. To assess the influence of the shape and size of the groove on the stress-strain state of the zone of conjugation of the weld metal with the base metal, FEM calculations were carried out

INVESTIGATION OF THE PROCESS OF RESTORATION OF DAMAGED PIPELINE SURFACES BY THE METHOD OF SURFACE RIVETING

Представлены результаты экспериментальных исследований процесса восстановления поврежденных поверхностей трубопроводов различных диаметров методом поверхностного наклепа, реализующего явление поверхностного пластического деформирования, приводящее к изменению распределения напряжений по толщине, выполнено обоснование оптимальных режимов его проведения . При этом было осуществлено численное моделирование процесса накатки, определены оптимальные значения следующих параметров: глубины и силы ППД, скорости ППД, подачи ролика, формы рабочей поверхности используемого ролика. При анализе были учтены следующие физико-механические характеристики: глубина наклепа, величина остаточных напряжений, глубина распределения остаточных напряжений, время обкатки, нагрузка на ролик. Доказано очевидное преимущество роликов большего радиуса профиля - они позволяют обеспечить необходимое изменение шероховатости обрабатываемой поверхности при обкатке с большей подачей, что приводит к снижению времени технологического процесса. При этом в принятом диапазоне параметров режимов обкатки (нагрузка 2500÷3000Н, глубина вдавливания 0.04÷0.06мм) величины компонентов остаточных напряжений оказались практически идентичными для исследованных режимов всех рассмотренных роликов. Полученные результаты были положены в основу технологии восстановительного ремонта трубопроводов различного диаметра без остановки производственного процесса на Нововоронежской АЭС и создана промышленная установка с числовым программным управлением для реализации данной технологии Here we present the results of experimental studies of the process of restoration of damaged surfaces of pipelines of various diameters by the method of surface work hardening, which implements the phenomenon of surface plastic deformation, leading to a change in the distribution of stresses along the thickness. At the same time, we carried out a numerical simulation of the knurling process, we determined the optimal values of the following parameters: the depth and strength of the SPD, the speed of the SPD, the feed of the roller, the shape of the working surface of the roller used. The analysis took into account the following physical and mechanical characteristics: work hardening depth, residual stress value, residual stress distribution depth, running time, roller load. We proved the obvious advantage of rollers with a larger profile radius - they allow one to provide the necessary change in the roughness of the machined surface during rolling with a higher feed, which leads to a decrease in the time of the technological process. In this case, in the accepted range of parameters of the running modes (load 2500-3000N, indentation depth 0.04-0.06 mm), the values of the residual stress components turned out to be almost identical for the considered modes for all the considered rollers. We used the results as the basis for the technology of restorative repair of pipelines of various diameters without stopping the production process at the Novovoronezh NPP and an industrial unit with numerical control was created to implement this technology

Surface plastic flow of 3D printed PLA in tribological study of surface patterned polymer

The potential of three-dimensional (3D) printing in polymer tribology is poorly explored. Material alignment and composition plays a vital role in altering the friction and wear characteristics of 3D printed materials. In the current study 3D patterns using fused deposition modeling are used to print advanced tribo-composites. Two different surface patterns (line and circular) are provided through 3D printing using white and silver Poly Lactic Acid (PLA). The deformation and the distribution of white and silver PLA over the samples surface are observed after the wear test. Results showed that the coefficient of friction is not being influenced by changing in the surface pattern. However, the wear rate increased for samples with line patterns on the contact surface, since the plastic flow was more significant in this case. Moreover, the filling factor exhibited an influence on increasing the plastic flow of the contact surface in case of the samples with line pattern.

The rolling simulation for cold work metal hardening

This article describes the results of a calculation and experimental analysis of destructive physical phenomena that appear in critical sections of industrial and power-related equipment, and lead to occurrence of various operational damages. It was shown that pipeline welded connections are the sections most prone to crack development, therefore the traditional strength calculations need to be combined with fracture mechanics criteria and thorough materials analysis of flawing and structural imperfection. The cold work hardening technique was proposed as a solution for the problem of critical sections performance property restoration. The technique uses surface plastic deformation phenomenon to change the material’s throughthickness stress distribution. In order to optimise surface hardening for welded connections prone to defect formation, we proposed a simulation for analysing an actual pipeline sections load. To assess the applicability of the simulation results, the cold work hardening technique was developed and introduced using a full-scale test sample for damaged areas of welded connections in ø426×40 vent pipes at Novovoronezh NPP Unit No.5.

Device for Wood-Cutting Tool Hardening

Choosing effective methods and devices for surface hardening of wood-cutting tools is problematic due to the variety of their designs and operating conditions. In this regard, the development of such devices becomes an urgent task. According to the literature, one of the effective methods for increasing the service life of machine parts and tools is electrospark hardening or electrospark alloying. Industrial electrospark installations such as “EFI” (electrophysical measurements) and “Elitron” with manual vibrators are used for electrospark hardening. However, using manual vibrators significantly increases the labour intensity and hardening time. Moreover, the surface quality after hardening with manual vibrators is often unsatisfactory. Various mechanized installations have been developed in order to reduce the labour intensity of electrospark hardening. Nevertheless, these installations are designed to harden specific parts and do not allow hardening tools of various designs, including woodcutting tools. The surface quality after hardening in mechanized installations does not always satisfy the customer. Further surface plastic deformation treatments, such as rolling and unrolling with rollers and balls, as well as diamond burnishing, are often used to improve the surface quality after electrospark hardening. The surface quality after additional processing by these methods boosts, although the labour intensity and cost of the hardening process increase. To increase the wear resistance of machine parts and tools, it is reasonable to reduce the height parameters of roughness, increase microhardness, and form the residual compressive stresses, which is ensured by the methods of surface plastic deformation. In this regard, it becomes necessary to use electrospark hardening simultaneously with surface plastic deformation. The work presents the design and features of using the device for hardening. The device was used to strengthen the thicknesser machine knives, which made it possible to almost double their durability. Applying this device, in comparison with using the electrospark hardening with a manual vibrator, reduces the roughness of the hardened surface and improves the surface quality of the processed workpieces. The modes of hardening have been installed, making it possible to effectively harden wood-cutting tools. For citation: Buglaev A.M. Device for Wood-Cutting Tool Hardening. Lesnoy Zhurnal [Russian Forestry Journal], 2021, no. 5, pp. 134–141. DOI: 10.37482/0536-1036-2021-5-134-141

FORMATION OF FUNCTIONAL PLASMA SPRAYED COATINGS WITH COMPLEX OF IMPROVED PHYSICAL, MECHANICAL AND OPERATIONAL PROPERTIES

The possibility of increasing the complex of physical, mechanical and operational properties of plasma sprayed coatings from powders of the PG-19M-01 and PRH18N9 grades due to the electric pulse effect on the heterophase high-temperature flow during spraying and next surface plastic deformation of the deposited coatings by shot blasting has been investigated. It is shown that shot blasting provides the formation of a hardening layer with a thickness of up to 180...200 μm, while the maximum level of microhardness is observed at a depth of about 60 μm. The microhardness of the coating from PG-19M-01 powder at the point of maximum hardening increases by 35%; steel coatings from PR-H18N9 powder – by 48% compared to the state after spraying. Experimental studies of the effect of this treatment on the bond strength and wear resistance of the obtained coatings have been carried out. It is shown that after shot-blasting the bond strength of the coatings decreases by 10...15%, and the wear resistance increases by 32...38%.

Morphological approach to the description of combined machining by cutting and surface plastic deformation with rollers of long shafts and pipes

The methodology and results of morphological analysis and synthesis of installation construction designs for combined machining of long shafts and pipes by cutting and surface plastic deformation (SPD) with self-feeding rollers are presented. It is shown which design options have already been implemented in practice, and which are promising.

Technological improvement of the durability of internal screw surfaces

The methods and some ways of technological improvement of the durability of internal screw surfaces are given. To increase the durability, finishing and strengthening machining with surface plastic deformation and threading with a cutter of a variable average diameter are proposed. The dependences for the specification of machining modes and the results of experimental studies of the screw surface quality parameters and wear resistance of running nuts are given.