Parts Of Hull Research Articles

Design and Manufacture of 3 Phase Electric Engine Hydrophore Control System

On board there is a temporary water reservoir called a hydrophore? Hydrophore serves to distribute fresh water that will flow to all parts of the ship's hull or accommodation on the ship, the hydrophore pressure tank cannot work for a long time if the ship is in black out condition. This research method is a type of Experimental research. Data collection techniques carried out are observation, design, making, measurement and documentation. The analysis method uses a descriptive analysis method by describing the working principle of the 3 Phase Electric Machine Hydrophore Control System that has been designed and made by the Research Team. The results of the study produced a 3 Phase Electric Machine Hydrophore Control System trainer we made with the hope that it can be a material or learning tool for students studying at the Polytechnic of Shipping Sciences, especially cadets / cadets of Diploma IV Shipping students who have not carried out sea practice so that when they carry out sea practice there is already an idea they get about the Hydrophore control system Although the tool we made is only a miniature because the tank we use is on a small size scale.

An Improved Method for Optimizing CNC Laser Cutting Paths for Ship Hull Components with Thicknesses up to 24 mm

In this paper, the essence and optimization objectives of the hull parts path optimization problem of CNC laser cutting are described, and the shortcomings of the existing optimization methods are pointed out. Based on the optimization problem of the hull parts CNC laser cutting path, a new part-cutting constraint rule based on partial cutting is proposed, which aims to overcome the drawbacks of the traditional algorithms with serial cutting constraint rules. This paper addresses the problem of optimizing the path for CNC laser cutting of hull parts, including an empty path and the order and directions used for the provided cut contours. Based on the discretization of the part contour segments, a novel toolpath model for hull parts called hull parts cutting path optimization problems based on partial cutting rules (HPCPO) is proposed in this paper. To solve the HPCPO problem, a segmented genetic algorithm based on reinforcement learning (RLSGA) is proposed. In RLSGA, the population is viewed as an intelligent agent, and the agent’s state is the population’s diversity coefficient. Three different segmented crossover operators are considered as the agent’s actions, and the agent’s reward is related to the changes in the population’s fitness and diversity coefficients. Two benchmark problems for HPCPO were constructed to evaluate the performance of RLSGA and compared with four other algorithms. The results showed that RLSGA outperformed the other algorithms and effectively solved the HPCPO problem.

Dynamic Spatiotemporal scheduling of hull parts under complex constraints in shipbuilding workshop

ABSTRACT The extremely competitive shipbuilding sector is going through a digital transformation in the context of Industry 4.0. The spatiotemporal problem has gained considerable attention during hull construction, particularly for blocks. There are fewer studies on intermediate products at lower levels, such as the dynamic spatiotemporal scheduling for hull parts under complex constraints in subassembly workshops. Therefore, this paper proposes a multi-queue two-level optimization method along with a dynamic spatiotemporal scheduling model based on the multi-directed acyclic graph (multi-DAG) and queueing theory. Firstly, a mathematical description of the complex constraints imposed by processing tasks and various resource types is provided. Then, a dynamic spatiotemporal scheduling model and an objective function are proposed to minimize the average time for parts in the system. At the sequencing level, different priority determination methods for queue events based on an improved genetic algorithm and the contribution ratio for release space strategy are proposed. At the service level, the allocation strategies for space and workers are constructed to improve utilization. Finally, several simulation experiments are conducted using the data gathered from the workshop. The proposed method is compared with the heuristic rules and combination rules using several queueing indicators and the space utilization vs. time graphs.

КОНСТРУКТОРСКО-ТЕХНОЛОГИЧЕСКИЕ РЕШЕНИЯ АДДИТИВНОГО ПРОИЗВОДСТВА КОРПУСНЫХ ДЕТАЛЕЙ МКА НК

In this article, research is carried out, technological recommendations are developed, including the choice of material, design solutions for hull parts of small spacecraft NC, taking into account the possibility of their manufacture by additive manufacturing methods and further robotic assembly on a turnkey basis.

Digital-twin based real-time resource allocation for hull parts picking and processing

Digital-twin based real-time resource allocation for hull parts picking and processing

ASSESSMENT OF THE RESIDUAL LIFE-TIME OF THE ELEMENTS OF THE CENTRIFUGAL PUMP OF THE ENERGY INSTALLATION ON THE BASIS OF STATISTICAL ASSESSMENT OF FATIGUE WITH PREDICTED WEAR DUE TO CORROSION

In this article, the residual resource of a centrifugal pump was anticipated, which operates an overestimated resource in the pumping line of a nuclear power plant. The results of theoretical and numerical modeling of its stress-strain state with a change in the geometry of the hull parts are presented. Three-dimensional FE models have been developed that take into account the actual geometry of pump parts, as well as a forecast of their possible changes during further operation. The change in the geometry of the structure is taken into account on the basis of extrapolation of data on the thickness of the hull walls obtained over a long service life. Calculations to determine the static strength are made for the main operating mode of the pump (under normal operating conditions). In places of welds, the cyclic strength was checked separately, while taking into account the decrease in their strength due to an increase in equivalent stress amplitudes by dividing them by the coefficient of reduction in the strength of the weld. The process of thinning of the wall of the pump housing under the action of erosive-corrosive wear is modeled. This process is random, so it was modeled taking into account the equations of wear growth kinetics. As a result of the research, the damage parameter and the probability of failure-free operation of the structure were obtained. These parameters are determined taking into account the predicted values of the percentage thinning of the pump housing wall and the obtained characteristics of the statistical deformation state of the structure.

Nanomodified Epoxy Materials with Improved Operating Characteristics

The purpose of the work is to develop new polymer composite nanomodified materials for the restoration of hull parts of agricultural machinery.As a result of research, a comparative analysis of the properties of composites based on epoxy resin ED-20 with the addition of 0.1-1.5 mass parts of carbon nanotubes “Taunit-M” obtained by free casting and direct pressing was carried out. The effectiveness of the developed compositions is proved when using them as binders in the production of fiber-reinforced composites.It was found that the introduction of 0.5 to 1 mass. parts CNT "Taunit" allows you to increase the strength characteristics of the resin ED-20 1.5-4 times with uniaxial tension, 2-2.5 times with three-point bending and reduce weight wear by 5-10 times.

Анализ способов изготовления разнонаправленных внутренних винтовых пазов трубных корпусных деталей и выбор инструмента для его реализации

Рассматривается возможность интенсификации процесса изготовления разнонаправленных внутренних винтовых пазов трубных корпусных деталей, используемых в судовых энергоустановках и пусковых устройствах для запуска подводных и летательных беспилотных аппаратов, и их элементов, испытывающих многократные нагрузки в период эксплуатации. Для выбора наиболее рационального и эффективного способа изготовления применен функционально-структурный анализ используемого оборудования для изготовления внутренних винтовых пазов трубных корпусных деталей, с помощью которого найдены закономерности процесса. Выявленный способ обработки, оборудования и применяемый инструмент являются наименее затратными и наиболее эффективными для выполнения необходимых технических требований. При проведении анализа зон локальных деформаций выявлен ряд зависимых величин, влияющих на конечное усилие и степень деформации при изготовлении разнонаправленных внутреннихвинтовых пазов трубных корпусныхдеталей. The following analysis deal with the possibility of intensification for the manufacturing process of the multi-directional internal screws of the pipe hull parts, used in the ship power plants and launch devices to launch submarine and unmanned aerial vehicles as well as their elements ,which experience multiple loads during their period of operation. Functional-structural analysis of the equipment, used for the manufacturing of the internal screws of the pipe hull parts, has been applied in deciding the most rational and efficient way of production. This analysis helps to find process patterns. The revealed way of machining, used equipment and the applied instrument provide the least expensive and the most effective results to execute necessary technical requirements. During executing local deformation areas analysis, there have been revealed a number of dependent values which make an impact on the final force as well as the deformation degree when manufacturing multi-directional internal screws of the pipe hull parts.

Methodology for determining the value of resistance to movement of a vehicle as a tool for research and optimization of the shape of the elements of a wheeled vehicle immersed in snow

The article presents an algorithm for simplified engineering calculation of the resistance to movement of a vehicle in the snow from the side of the hull parts and shows a software implementation with a description of the mechanism of work. Plans are presented for further improvement of this software, in particular, the introduction of resistance values for various materials into the calculation. A comparison is also made with traditional methods for calculating the resistance to movement.

The assessment of impact damage caused by dropped objects on floating offshore structures

Offshore facilities are exposed to the risk of accidental damages caused by fire, explosion, dropped objects, extreme environmental events and vessel collision poses a big threat to the safety and operation. During any lifting work, either from a supply vessel to the installation or from within the installation or plant itself, there is a potential danger when objects are being lifted for a dropped object accident to take place. This paper introduces extensive dropped object analyses applied in the design of Floating Production Storage Offloading (FPSO) offshore units, where non-linear finite element analyses are performed using an explicit LS-DYNA tool. In the structural evaluation, the hull parts such as infill deck, galley, and main lay-down located on poop deck, and cargo deck are taken into account. The dropped objects study is to find out what happens to the FPSO hull structure if the heavy items are dropped. The drop object impact analyses show that even though some structural members were permanently deformed by drop loads, however, there was no failure taken place in accordance with the plastic strain criteria as per NORSOK Code. It is discovered that the pillars supporting the main lay-down area have not been suffered from buckling failure through examined reaction forces. Further, the impact resistance of a deck depends on the plate thickness and the size and spacing of the supporting stringers.

CONCEPTUAL OPTIMIZATION OF FLEXIBLE MACHINE BUILDING PRODUCTION

Based on the use of simulation modeling, approaches to the definition of the essence of conceptual optimization as an essential element of preplanned research, which is currently underdeveloped, are shown. To resolve the contradictions of the integral process of building and researching a complex automated production, the following contradictions and areas of the latest developments in flexible production have been identified in the work: coordination of the growing content in technology, design and production management; integration of modular local systems of new quality; stabilization and reduction of the cost of fixed assets; stabilization and increase the level of automation of production.The paper substantiates the need for orientation of the latest developments on the optimization of flexible industrial production in the following areas: modeling of design tasks in the process of pre-planned studies with justification of the way of forming system functions and mechanisms of their organization; the formation of ways of organizing and discrete formalization of the functional cycles of the passage of objects through the production system; regulation of the technological interval, which dictates the principle of functioning of a flexible system and a new way of organizing production; design of the system version of flexible production with ranges of internal organization parameters.The approach proposed in the work contributes to: increasing the cycle and technological productivity, which will be ahead of the investment spent; high flexibility of transition to new, constantly changing products; high-quality product upgrades with low energy supply and high resource utilization; improving the comfort of working conditions, environmental safety in relation to existing technologies. But at the same time, high-performance flexible systems can provide their inherent qualities subject to appropriate changes in the environment and the conditions for the use of new equipment, that is, a modular organization of production.Testing of the research results took place on a really operating flexible manufacturing system for machining hull parts at a machine tool enterprise.

Structure and Mechanical and Technological Properties of Additive Material for Welding Heat-Resistant Steels

The analysis of casting defects in the hull parts of power equipment, and their elimination methods. The development directions of foreign researchers in the field of heat-resistant steels welding are established and analyzed. The prospects of using pearlite material for electric arc welding of defects is shown. The results of studies of the welding material of a pearlite structure, microalloyed by rare-earth metals, with high welding-technological, viscoplastic properties and impact strength are presented. An analysis of the state of scientific developments of metallurgists, material scientists and welders shows that, to ensure high viscoplastic properties of steel products, a promising direction is the use of rare earth metals as modifiers and microalloying additives as desulfurizers. The welding process is carried out without heating and subsequent heat treatment. For research, an experimental batch of electrodes was manufactured as rods in which the wire SV-08A was used. Doping was provided through an electrode coating. Alloying with rare-earth metals was carried out by introducing yttrium ligature into the coating, it was found that the introduction of rare-earth metals into the deposited metal allows to obtain high visco-plastic properties of the metal without reducing the carbon content, which, in turn, provides strength properties at the level specified by regulatory documentation.

Studies on applying hot-rolled coil to hull superstructure

Application of the hot-rolled steel sheet for the members of superstructure, where the strength requirement of these parts in ships is not severe, is expected as a solution to reduce the hull construction cost. Because the hot-rolled steel sheet is applied after recoiling by cold working to return it to a flat plate, the material properties is deteriorated due to excessive plastic working and the residual stress induced by the plastic work might affect for the thermal cutting and welding. There is a possibility that the hot-rolled steel sheet has poor properties comparing with the flat rolled steels applied for hull parts where the structural integrities are required by the classification societies’ rules. The difference of properties between the hot-rolled steel sheet and the flat rolled steel are investigated in this research.

Nassarius foveolatus (Gastropoda, Nassariidae), a new record of an exotic species in Brazil

Exotic species are those that occur in an area beyond their natural limit and they are considered invasive when they cause harm to the economy, environment, or human health. In coastal environments, ballast water and inlays on the hull and other parts of vessels are the main ways of introducing invasive aquatic alien species. Nassarius foveolatus (Dunker, 1847) is native from the Central and East Indian Ocean to the East China Sea. The first specimens (empty shells) of N. foveolatus were collected manually on November 11, 2017 on the Rocio footbridge, located in the Paranaguá Estuarine Complex, on the coast of the State of Paraná, southern Brazil. Posteriorly, live specimens were collected in other localities of this bay. It is already possible to infer that the specimens of N. foveolatus occur together with the native specimens of N. vibex (Say, 1822), having the same niche. As previously only N. vibex existed in that place, at least a displacement of this native species has been occurred. However, certainly future ecological studies may confirm this displacement and additional consequences to the local ecosystem, as nassariids can be predators and scavengers. Control procedures should be also greatly implemented.

Mechanical behavior of patched steel panels at elevated temperatures

Preventive maintenance is an accepted practice in engineering to keep the structural reliability of ship hulls at the highest possible level. Designers ensure a longer period in between the consecutive maintenance of ship hull parts to optimize expenditure. This is relevant in view of the difficulty in reaching farthest corners in ballast tanks, fuel storage tanks, cofferdams etc. Prior maintenance of the deck and hull parts save a considerable amount of the owner’s budget.A portable technology like patching becomes more handy and economic. Performance of both unpatched and patched samples during dynamic loading conditions being examined in the present investigation. The high strength steel panels with a dimension of 70mm×15mm×3mm were edge cracked for lengths of 4mm and 7mm, with width of 1mm for both. The edge cracked high strength steel panels are repaired with composite patches using GFRP (glass fiber reinforced plastic), CFRP (carbon fiber reinforced plastic) and AFRP (aramid fiber reinforced plastic). The patching was done by 3 and 5 layered and impact tested by Charpy impact tester at ranges of high temperatures. The amount of energy absorbed in the impact is converted to dynamic fracture toughness values and compared for evaluating the performance of FRP (fiber reinforced plastics). Finite element analysis was done for evaluating the stress intensity factors at different types of patching and testing conditions. Comparatively the AFRP patched samples showed better dynamic fracture toughness values at different temperatures.

Technology development and material science substantiation of cold bending for ship hulls parts of high-strength steels and alloys by local deformation

At JSC “PO “Sevmash” a technology of cold bending for ship hull parts from high-strength steels and alloys has been developed by the method of local deformation. A material science substantiation of its implementation has been given. In addition to the practical positive side of parts manufacturing, the local deformation is cost-effective and can significantly reduce the cost of manufacturing parts.

Анализ полного сопротивления корпуса судна на различных скоростях хода

The paper shows method for analyzing total resistance of ship which calculated on Froude numbers from 0.14 to 0.41. To this method the hull surface divides into its component surfaces to the ship length. This approach allows to calculate the distribution of resistance forces along the ship length. Based on this data hull zones for correcting can be selected, and a better comparison of several hull can be made. First of all mathematical scheme of total resistance calculating develops and validates in the OpenFOAM software. The standard solver interDyMFoam and DTMB 5415 hull data uses. Three grids uses for mesh convergence. To implement the proposed method the DTMB 5415 hull divides into 22 surfaces along the length. According to the results of numerical simulations the curves of distribution of resistance force along the hull length for the different ship speeds obtain. Due to analysis of curves two versions of hull develops based on DTMB 5415 hull: without bulb and with streamlined bulb. Both hulls have lower resistance at all speeds compared to the DTMB 5415 base hull. Due to analysis of resistance force distribution curves of new hulls distributed resistance force on middle and stern parts of hull does not depend on ship speed and stem part lines. Stem part of hull has the most important influence on total resistance.

МОДИФИКАЦИЯ ЭЛАСТОМЕРА ДЛЯ ВОССТАНОВЛЕНИЯ КОРПУСНЫХ ДЕТАЛЕЙ АВТОТРАКТОРНОЙ ТЕХНИКИ

Body parts are typical, most material-intensive and expensive parts. When repairing worn out hull details, the costs for repairing equipment are significantly reduced, in comparison with the manufacture of new ones, the consumption of metal, electricity, and environmental pollution is reduced.
 Unlike many other methods, the methods of restoring body parts with polymeric materials are technologically simple, do not require large energy inputs and high qualification of the personnel. Due to the polymer layer, the stresses in the contact zone of loaded bodies with the bearing raceways decrease and its durability increases, there is no fretting corrosion and the service life of the bearing and body part increases manyfold. The use of polymeric composites can significantly improve the efficiency of restoring body parts. This is due to increased thermal conductivity, thermal and heat resistance, lower cost of composites in comparison with non-filled polymers. A promising direction in improving the consumer properties of the material is the filling of the polymer matrix with nanoscale particles. The nanocomposite based on elastomer F-40 filled with aluminum and copper nanoparticles has been developed and thoroughly studied at the LSTU. The material is designed to restore the landing holes in the hull parts of the tractor equipment. The article presents the results of experimental studies and analysis of deformation-strength and adhesion properties of a nanocomposite, its optimal composition is justified. Comparative results of the study of heat resistance and thermal stability of the F-40 elastomer and a nanocomposite based on are presented. It is shown that the nanocomposite has higher consumer properties than the F-40 elastomer: the strength and endurance are increased to 1.3 times, the heat resistance is up to 123C, the aging coefficients are 1.8 times higher in strength, 1.4 times in deformation.

Analysis and Parameter Identification of Automatic Cannon Carriages

<p class="p1">Experimental procedures for the research of vibrations in automatic weapons mounted on combat vehicles is introduced. Experiment preparation procedures, experience and examples of evaluation of measured results in direct fire from a tracked combat vehicle are explained on BMP-2 IFV example. The result is the movements of the turret and the hull of a combat vehicle in single shot firing, and short and long burst firing. In addition to time domain analysis, methods of correlation and spectral analysis are used. Live firing experiments are complemented by laboratory experiments and are used to determine model parameters for calculations such as stiffness and damping in the suspensions of the hull, elevation parts, clearance in the elevating gear, and the natural vibration frequency of the hull and elevation parts.</p>

SeaShips: A Large-Scale Precisely Annotated Dataset for Ship Detection

In this paper, we introduce a new large-scale dataset of ships, called SeaShips, which is designed for training and evaluating ship object detection algorithms. The dataset currently consists of 31 455 images and covers six common ship types (ore carrier, bulk cargo carrier, general cargo ship, container ship, fishing boat, and passenger ship). All of the images are from about 10 080 real-world video segments, which are acquired by the monitoring cameras in a deployed coastline video surveillance system. They are carefully selected to mostly cover all possible imaging variations, for example, different scales, hull parts, illumination, viewpoints, backgrounds, and occlusions. All images are annotated with ship-type labels and high-precision bounding boxes. Based on the SeaShips dataset, we present the performance of three detectors as a baseline to do the following: 1) elementarily summarize the difficulties of the dataset for ship detection; 2) show detection results for researchers using the dataset; and 3) make a comparison to identify the strengths and weaknesses of the baseline algorithms. In practice, the SeaShips dataset would hopefully advance research and applications on ship detection.