Determination of Parameters Describing the Risk Areas of Ships Chaotic Rolling on the Example of LNG Carrier and OSV Vessel

One of the significant problems in the safe operation of vessels is the behavior of the ship on the wave. Of all degrees of freedom, the greatest threat to the safety of a ship is associated with excessive rolling. One of the best methods to improve the safety of a ship in this field is to carry out experiments on the ship model, performed at her design stage. The problem is that the model tests are costly. An alternative is to conduct simulation tests based on numerical models. The primary goal of the article is to present the results of the simulation regarding the determination of parameters describing the risk areas of chaotic rolling for the ship designed for transporting liquefied natural gas (LNG carrier) and offshore support vessel (OSV). The first discusses the state of knowledge on mathematical modeling of oscillations. Then, the theory of nonlinear differential equations is presented, and the mathematical model of ship rolling is described. This model is used to prepare and conduct a numerical simulation in the Mathematica package. The results of these studies and their discussion constitute the central part of the article. Finally, the conclusions are presented.

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Determining the width of the ship’s course using a mathematical model to ensure the safety of the ship’s navigation

Journal of Physics Conference Series ◽

10.1088/1742-6596/2131/3/032034 ◽

2021 ◽

Vol 2131 (3) ◽

pp. 032034

Author(s):

O Lebedev ◽

I Lipatov

Keyword(s):

Mathematical Model ◽

Time Interval ◽

Safe Operation ◽

Drift Angle ◽

Model Experiments ◽

Urgent Task ◽

The Mathematical Model ◽

Over Time ◽

Shift Angle

Abstract Determination of the ship’s course width necessary for the ships safe operation is an urgent task due to the increase in the modern ships’ dimensions. The existing methods for assessing the fairway are calculated with a full re-positioning of the propulsion-rudder complex, according to the maximum drift angle. The vessel movement is considered to be steady, that is, the speed, the drift angles do not depend on time. The relevance of this study is associated with the assessment of determining the width of the fairway at any time interval. This is due to the fact that when passing the river sections, the vessels perform maneuvering with the rudder gear shifted for short periods of time and not at the maximum shift angle. Determination of the parameters of the ship’s movement over time when the navigator manipulates the ship’s controls (control of the rudder device, changing the parameters of the main engines) can be determined by the mathematical model of the ship’s movement. This article discusses the issues of creating a model that adequately describe the processes of vessel movement, including in the conditions of vessel movement along a limited ship’s course. The adequacy of the model was verified using the data of field and model experiments. According to the compiled mathematical model, the calculations were made for various projects of dry cargo ships.

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Nonlinear Spatial Localized Strain Waves

EPJ Web of Conferences ◽

10.1051/epjconf/201818302030 ◽

2018 ◽

Vol 183 ◽

pp. 02030

Author(s):

Vladimir I. Erofeev ◽

Sergey I. Gerasimov ◽

Alexey O. Malkhanov

Keyword(s):

Equations Of State ◽

Numerical Models ◽

Hydrodynamic Instability ◽

Light Sources ◽

Third Order ◽

Simultaneous Excitation ◽

Wave Guides ◽

Determination Of Parameters ◽

The Waves

A possible way of study of single waves in solids is discussed. The soliton is one of these waves without shape and parameters varying. Soliton deformation parameters are connected with the elastic moduli of the third order that allows defining values of these moduli by means of the measured solitondeformation parameters in various type waveguides made of the same material. The conditions under which a soliton can exist in a rod are analytically determined. For simultaneous excitation of loading in several wave guides two new energetic photosensitive structures (the mixtures are given) initiated by means of short light impulses of noncoherent light sources are proposed. Conditions of excitation of the waves on the basis of multipoint optical initiation loading impulses are described. As a technique for registration the shadowgraph visualization is proposed. It is discussed, how the problem connected to the use of energetic initiation structures consisting in the power background illumination can be solved. The shadow scheme with the use of a tiny dot explosive light source (Tbr ~41 kK) allows to carry out modelling experiments on research of slabbing actions, jet formations, fluffings, hydrodynamic instability during shock-wave loading of investigated samples, which makes it attractive for determination of parameters in equations-of-state for investigated materials, creation of numerical models and their validation. Some examples showing basic possibility of application of the declared techniques are included.

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Optimal cutting and prediction of assortment yields before and during tree felling

Известия СПбЛТА ◽

10.21266/2079-4304.2019.229.176-184 ◽

2019 ◽

Author(s):

А.С. Торопов ◽

А.Н. Соловьев

Keyword(s):

Mathematical Model ◽

Exhaustive Search ◽

Maximum Volume ◽

New Approach ◽

Optimum Cutting ◽

Sexual Part ◽

Determination Of Parameters ◽

The Mathematical Model

В настоящей статье рассматривается новый подход к проблеме оптимального раскроя и прогнозирования выхода сортиментов до и в процессе валки деревьев. Авторы предлагают и теоретически обосновывают рациональный раскрой пиловочной части дерева по критерию максимального объемного выхода пиловочника в стоимостном выражении. В работе приведена математическая модель определения параметров половой части дерева на основе аллометрического метода исследований предмета труда и оптимального раскроя и прогнозирования выхода сортиментов до и в процессе валки деревьев с использованием метода исчерпывающего поиски и методы ветвей и границ. In this article new approach to a problem of optimum cutting and forecasting of an exit of assortments to and in process rolls of trees is considered. Authors offer and theoretically prove rational cutting of a pilovochny part of a tree by criterion of the maximum volume exit of sawlog in value terms. In work the mathematical model of determination of parameters of a sexual part of a tree on the basis of anallometrichesky method of researches of an object of the labor and optimum cutting and forecasting of an exit of assortments to and is given in process rolls of trees with use of a method exhaustive search and methods of branches and borders.

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APPLICATION OF FMEA METHODOLOGY FOR CHECKING OF CONSTRUCTION’S PROJECT DOCUMENTATION AND DETERMINATION OF THE MOST RISK AREAS

Acta Polytechnica ◽

10.14311/ap.2020.60.0448 ◽

2020 ◽

Vol 60 (5) ◽

pp. 448-454

Author(s):

Martin Tuháček ◽

Ondřej Franek ◽

Pavel Svoboda

Keyword(s):

Data Collection ◽

Design Stage ◽

Construction Companies ◽

Innovative Method ◽

Project Documentation ◽

Risk Areas

The article deals with an innovative method designed to check project documentation of buildings at the design stage, specifically exploring the possibility to implement FMEA and PDCA methodologies. Based on performed measurements and data collection, it theoretically determines the riskiest areas of the project documentation, which should be given special attention in order to reduce later costs for construction companies to fix the reported complaints. The research proves that the application of the FMEA and PDCA methodology can be very useful regarding the elimination of defects in the project documentation of constructions already in the phase of construction preparation.

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ACCURATE DETERMINATION OF PARAMETERS OF INTERNAL FRICTION ASSOCIATED WITH GRAIN BOUNDARY

Le Journal de Physique Colloques ◽

10.1051/jphyscol:19851085 ◽

1985 ◽

Vol 46 (C10) ◽

pp. C10-379-C10-382

Author(s):

JIANG ZI-YING ◽

CAI WEI-PING

Keyword(s):

Internal Friction ◽

Grain Boundary ◽

Accurate Determination ◽

Determination Of Parameters

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DETERMINATION OF PARAMETERS OF HIGH TEMPERATURE INTERNAL FRICTION FROM SINGLE EXPERIMENTAL CURVE

Le Journal de Physique Colloques ◽

10.1051/jphyscol:1987847 ◽

1987 ◽

Vol 48 (C8) ◽

pp. C8-323-C8-327

Author(s):

Z. JIANG ◽

X. ZHU ◽

W. FAN

Keyword(s):

High Temperature ◽

Internal Friction ◽

Experimental Curve ◽

Determination Of Parameters

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DETERMINATION OF PERFORMANCE INDICATORS OF THE TRUCK KrAZ-6510TE

Avtoshliakhovyk Ukrayiny ◽

10.33868/0365-8392-2020-1-261-19-26 ◽

2020 ◽

pp. 19-26

Author(s):

Olexandr Pavlenko ◽

Serhii Dun ◽

Maksym Skliar

Keyword(s):

Mathematical Model ◽

Surface Friction ◽

Building Structures ◽

Maximum Torque ◽

Military Equipment ◽

Military Vehicles ◽

Force Magnitude ◽

Vehicle Mobility ◽

The Mathematical Model

In any economy there is a need for the bulky goods transportation which cannot be divided into smaller parts. Such cargoes include building structures, elements of industrial equipment, tracked or wheeled construction and agricultural machinery, heavy armored military vehicles. In any case, tractor-semitrailer should provide fast delivery of goods with minimal fuel consumption. In order to guarantee the goods delivery, tractor-semitrailers must be able to overcome the existing roads broken grade and be capable to tow a semi-trailer in off-road conditions. These properties are especially important for military equipment transportation. The important factor that determines a tractor-semitrailer mobility is its gradeability. The purpose of this work is to improve a tractor-semitrailer mobility with tractor units manufactured at PJSC “AutoKrAZ” by increasing the tractor-semitrailer gradeability. The customer requirements for a new tractor are determined by the maximizing the grade to 18°. The analysis of the characteristics of modern tractor-semitrailers for heavy haulage has shown that the highest rate of this grade is 16.7°. The factors determining the limiting gradeability value were analyzed, based on the tractor-semitrailer with a KrAZ-6510TE tractor and a semi-trailer with a full weight of 80 t. It has been developed a mathematical model to investigate the tractor and semi-trailer axles vertical reactions distribution on the tractor-semitrailer friction performances. The mathematical model has allowed to calculate the gradeability value that the tractor-semitrailer can overcome in case of wheels and road surface friction value and the tractive force magnitude from the engine. The mathematical model adequacy was confirmed by comparing the calculations results with the data of factory tests. The analysis showed that on a dry road the KrAZ-6510TE tractor with a 80 t gross weight semitrailer is capable to climb a gradient of 14,35 ° with its coupling mass full use condition. The engine's maximum torque allows the tractor-semitrailer to overcome a gradient of 10.45° It has been determined the ways to improve the design of the KrAZ-6510TE tractor to increase its gradeability. Keywords: tractor, tractor-semitrailer vehicle mobility, tractor-semitrailer vehicle gradeability.

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