scholarly journals Simulation model for assessing the safety of water transport

2021 ◽  
pp. 20-27
Author(s):  
В.Ю. Каминский ◽  
Д.А. Скороходов ◽  
А.Л. Стариченков ◽  
Н.В. Никитин
Keyword(s):  
Simulation Model ◽  
Water Transport ◽  
Quantitative Assessment ◽  
Functional Dependence ◽  
A Priori ◽  
Design Stage ◽  
Safety Level ◽  
Proposed Model ◽  
Full Scale Tests ◽  
Relationship Of

Показано, что выявление объективных причин аварий водного транспорта и последующее их устранение способствует радикальному повышению уровня безопасности. Сформирована причинно-следственная схема возникновения аварий водного транспорта в зависимости от главных, непосредственных, объективных и сопутствующих причин. Установлено, что при обосновании рациональных способов априорной количественной оценки степени опасности проектируемого оборудования необходимо исходить из неприемлемости проведения специальных натурных испытаний, инициирующих аварии. С этой целью рекомендуется имитационное моделирование. Предложена имитационная модель оценки вероятности возникновения аварий в процессе эксплуатации энергетической судовой установки. Функционирование имитационной модели основано на том, что возникновение происшествий является следствием развития причинно- следственной связи предпосылок, триггерами и составными частями которой являются ошибочные действия или бездействие членов команды судна, неполадки и отказы технологического оборудования, а также неучтенное воздействие внешних факторов. Систематизированы факторы, способствующие возникновению аварий и инцидентов, в составе которых: технические факторы; личностные и факторы воздействия внешней среды В общем виде решение задачи обеспечения безопасности судна с использованием предложенной модели сводится к отысканию функциональной зависимости вероятности возникновения аварии и оценкой факторов опасности, которая уже на стадии проектирования судового оборудования позволяет количественно оценить вероятность возникновения аварий в процессе эксплуатации водного транспорта. Приведен пример количественной оценки вероятности возникновения аварии. Предложено в состав обязательных документов, обеспечивающих проектирование водных транспортных средств, включать «Программу обеспечения безопасности», которая должна определять перечень работ и мероприятий, проводимых на всех стадиях жизненного цикла судна. It is shown that the identification of objective causes of accidents of water transport and their subsequent elimination contributes to a radical increase in its safety level. A causal scheme of the occurrence of accidents of water transport has been formed, depending on the main, direct, objective and concomitant causes. It is established that when justifying rational methods of a priori quantitative assessment of the degree of danger of the designed equipment, it is necessary to proceed from the unacceptability of conducting special full-scale tests that initiate accidents. For this purpose, simulation modeling is recommended. A simulation model for estimating the probability of accidents during the operation of a ship's power plant is proposed. The functioning of the simulation model is based on the fact that the occurrence of accidents is a consequence of the development of a causal relationship of prerequisites, the triggers and components of which are erroneous actions or inaction of the ship's crew members, malfunctions and failures of technological equipment, as well as the unaccounted impact of external factors. The factors contributing to the occurrence of accidents and incidents are systematized, including: technical factors; personal and environmental factors In general, the solution of the problem of ensuring the safety of a vessel using the proposed model is reduced to finding the functional dependence of the probability of an accident and assessing the hazard factors, which already at the design stage of ship equipment allows us to quantify the probability of accidents during the operation of water transport. An example of a quantitative assessment of the probability of an accident is given. It is proposed that the "Safety Program" should be included in the mandatory documents that ensure the design of water vehicles, which should determine the list of works and activities carried out at all stages of the vessel's life cycle.

The impact of duration observations on precision of results GNSS measurements

2017 ◽  
Vol 921 (3) ◽  
pp. 7-13 ◽  
Author(s):  
S.V. Grishko
Keyword(s):  
Measurement Accuracy ◽  
Functional Dependence ◽  
Observation Time ◽  
Satellite Networks ◽  
Satellite Measurements ◽  
Proposed Model ◽  
Actual Error ◽  
Gnss Measurements ◽  
The Impact ◽  
Qualitative Characteristics

This paper shows that the accuracy of relative satellite measurements depend not only on the length of the baseline, as it is regulated by the rating formula of accuracy of GNSS equipment, but also on the duration of observations. As a result of the strict adjustment much redundant satellite networks with different duration of observations obtained covariance matrix of baselines, the most realistic reflecting the actual error of satellite observations. Research of forms of communication of these errors from length of the baseline and duration of its measurement is executed. A significant influence of solar activity on accuracy of satellite measurements, in general, leads to unequal similar series of measurements made at different periods, for example, in the production of monitoring activities. The model of approximation of the functional dependence of accuracy of the baseline from its length and duration of observations having good qualitative characteristics is offered. Based on the proposed model, we analyzed the dynamics of changes in measurement accuracy with an increase in observation time.

scholarly journals Numerical Investigation for the Resin Filling Behavior during Ultraviolet Nanoimprint Lithography of Subwavelength Moth-Eye Nanostructure

Coatings ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 799
Author(s):  
Yuanchi Cui ◽  
Xuewen Wang ◽  
Chengpeng Zhang ◽  
Jilai Wang ◽  
Zhenyu Shi
Keyword(s):  
Simulation Model ◽  
Nanoimprint Lithography ◽  
Cfd Simulation ◽  
Boundary Slip ◽  
Accurate Analysis ◽  
Inlet Velocity ◽  
Filling Height ◽  
Proposed Model ◽  
Good Consistency ◽  
Computational Fluid Dynamics Cfd

Accurate analysis of the resin filling process into the mold cavity is necessary for the high-precision fabrication of moth-eye nanostructure using the ultraviolet nanoimprint lithography (UV-NIL) technique. In this research, a computational fluid dynamics (CFD) simulation model was proposed to reveal resin filling behavior, in which the effect of boundary slip was considered. By comparison with the experimental results, a good consistency was found, indicating that the simulation model could be used to analyze the resin filling behavior. Based on the proposed model, the effects of process parameters on resin filling behavior were analyzed, including resin viscosity, inlet velocity and resin thickness. It was found that the inlet velocity showed a more significant effect on filling height than the resin viscosity and thickness. Besides, the effects of boundary conditions on resin filling behavior were investigated, and it was found the boundary slip had a significant influence on resin filling behavior, and excellent filling results were obtained with a larger slip velocity on the mold side. This research could provide guidance for a more comprehensive understanding of the resin filling behavior during UV-NIL of subwavelength moth-eye nanostructure.

Mechanical Performance Simulation Model Based on PDM

2013 ◽  
Vol 300-301 ◽  
pp. 32-35
Author(s):  
Xiao Wen Zeng ◽  
Cheng Zeng ◽  
Bing Han
Keyword(s):  
Simulation Model ◽  
Mechanical Performance ◽  
Product Structure ◽  
Dynamics Simulation ◽  
Simulation Data ◽  
Performance Simulation ◽  
Collaborative Simulation ◽  
Complex Simulation ◽  
Mechanical Dynamics ◽  
Relationship Of

In order to manage the complex simulation data management in the process of mechanical dynamics simulation, a new management model was presented which is Performance Simulation Model(PSM). The model was based on PDM product structure and the concepts and elements of PSM were defined in this paper. Furthermore, the functional framework of PSM was proposed which based on the hierarchical relationship of product structure and the data stream relationship of data structure matrix. Finally, PSM was applied on ship planetary reducer collaborative simulation platform. The result indicates that the simulation data in mechanical collaborative simulation are managed by PSM, and the problem of interaction between collaborative simulation and PDM is solved.

Semi-inverse method for predicting stress–strain relationship from cone indentations

2003 ◽  
Vol 18 (9) ◽  
pp. 2068-2078 ◽  
Author(s):  
A. DiCarlo ◽  
H. T. Y. Yang ◽  
S. Chandrasekar
Keyword(s):  
A Priori ◽  
Model Material ◽  
Material Behavior ◽  
The Finite Element Method ◽  
Stress Strain ◽  
Indentation Tests ◽  
Strain Relationship ◽  
Initial Force ◽  
Relationship Of ◽  
Force Displacement

A method for determining the stress–strain relationship of a material from hardness values H obtained from cone indentation tests with various apical angles is presented. The materials studied were assumed to exhibit power-law hardening. As a result, the properties of importance are the Young's modulus E, yield strength Y, and the work-hardening exponent n. Previous work [W.C. Oliver and G.M. Pharr, J. Mater. Res. 7, 1564 (1992)] showed that E can be determined from initial force–displacement data collected while unloading the indenter from the material. Consequently, the properties that need to be determined are Y and n. Dimensional analysis was used to generalize H/E so that it was a function of Y/E and n [Y-T. Cheng and C-M. Cheng, J. Appl. Phys. 84, 1284 (1999); Philos. Mag. Lett. 77, 39 (1998)]. A parametric study of Y/E and n was conducted using the finite element method to model material behavior. Regression analysis was used to correlate the H/E findings from the simulations to Y/E and n. With the a priori knowledge of E, this correlation was used to estimate Y and n.

The Constitutive Model for High Temperature Flow Behavior of SiC/6168Al Composite

2015 ◽  
Vol 1089 ◽  
pp. 37-41
Author(s):  
Jiang Wang ◽  
Sheng Li Guo ◽  
Sheng Pu Liu ◽  
Cheng Liu ◽  
Qi Fei Zheng
Keyword(s):  
Constitutive Model ◽  
Hot Deformation ◽  
Flow Behavior ◽  
Type Equation ◽  
Strain Rate Range ◽  
Compression Tests ◽  
Stress Strain ◽  
Hollomon Parameter ◽  
Proposed Model ◽  
Relationship Of

The hot deformation behavior of SiC/6168Al composite was studied by means of hot compression tests in the temperature range of 300-450 °C and strain rate range of 0.01-10 s-1. The constitutive model was developed to predict the stress-strain curves of this composite during hot deformation. This model was established by considering the effect of the strain on material constants calculated by using the Zenter-Hollomon parameter in the hyperbolic Arrhenius-type equation. It was found that the relationship of n, α, Q, lnA and ε could be expressed by a five-order polynomial. The stress-strain curves obtained by this model showed a good agreement with experimental results. The proposed model can accurately describe the hot flow behavior of SiC/6168Al composite, and can be used to numerically analyze the hot forming processes.

THE RULE OF COMBINING A PRIORI AND EXPERIMENTAL INFORMATION IN THE TASKS OF MANAGING TESTS OF COMPLEX TECHNICAL PRODUCTS ACCORDING TO THE BERNOULLI SCHEME

2020 ◽  
pp. 3-13
Author(s):  
Yu. I. Buryak ◽  
A. A. Skrynnikov
Keyword(s):  
Field Experiments ◽  
A Priori ◽  
Field Tests ◽  
Experimental Information ◽  
Full Scale ◽  
Testing Complex ◽  
Series Of Experiments ◽  
Full Scale Tests ◽  
Technical Products

The article is devoted to the substantiation of the procedure for testing complex technical systems to assess the probability of performing the task, taking into account a priori data obtained from the results of modeling, field tests of components and prototypes, operation of analogues, etc. The conditions for the formation of a combined sample consisting of field experiments and experiments counted on the results of modeling are justified. Data uniformity is checked using the Student's criterion. The minimum volume of full-scale tests is determined by the requirement of equality of the amount of Fischer information about the estimated parameter obtained during full-scale tests and at the expense of a priori data A strategy for conducting field experiments is proposed, in which the required quality of evaluating the probability of completing the task is achieved with the minimum possible number of field experiments. At the first stage, a series of experiments with a volume equal to half of the required sample size is performed. At the second stage, the experiments are conducted sequentially with an assessment after each experiment of the requirements for the amount of information about the evaluated parameter and for the uniformity of data. Experiments are terminated when the specified requirements are met, and then a combined sample is formed, which is used to evaluate the probability of the system performing the task. A model example is considered. The estimation of the gain in the number of experiments performed at different probability values was carried out.

On Designing for Enhanced Product Sustainability by Considering the Induced Residual Stresses in Machining Operations

2007 ◽  
Author(s):  
J. C. Outeiro ◽  
O. W. Dillon ◽  
I. S. Jawahir
Keyword(s):  
Residual Stresses ◽  
Carbon Steels ◽  
Design Stage ◽  
Machining Parameters ◽  
Safety Level ◽  
Modeling And Control ◽  
Inconel Alloys ◽  
Product Lifetime ◽  
Maintenance And Inspection ◽  
Machining Operations

For improving product sustainability, a number of measures can be adopted during the product design stage for manufacturing. The modeling and control of the residual stresses and surface roughness generated by machining are among the major measures which have been shown to demonstrate the strongest influence on the machined component’s performance during its service life. The proper control of the residual stresses would provide increased product lifetime, reduced part distortion, reduced weight and reduced and less frequent maintenance and inspection of the product while maintaining the same safety level, or perhaps even improving it. This paper presents an analysis of the influence of machining parameters on the residual stresses generated in machining operations. This analysis was performed on several work materials, including carbon steels, stainless steels, Inconel alloys and tool steels. This allows developing a number of feasible means to control the residual stresses during manufacturing.

scholarly journals ОСОБЛИВОСТІ АВТОМАТИЗАЦІЇ КОНТРОЛЮ ТЕХНІЧНОГО СТАНУ МОРСЬКОГО ТРАНСПОРТУ

World Science ◽  
2019 ◽  
Vol 1 (3(43)) ◽  
pp. 19-25
Author(s):  
Коломієць Оксана Михайлівна
Keyword(s):  
Water Transport ◽  
A Priori ◽  
Technical Condition ◽  
Software Implementation ◽  
Effective Strategy ◽  
Kutta Method ◽  
A Priori Information ◽  
Automated Control ◽  
Runge Kutta Method ◽  
Priori Information

The article analyzes the principles of automation of the control of the technical condition of water transport vehicles, which has been determined: the principle of coherence; the principle of integration; Principle of independence of execution.It is determined that the most effective strategy is to improve the methods of automated control of the technical condition of water transport vehicles, which, unlike existing ones, is based on Markov processes, the Runge-Kutta method of numerical solution of the system of Kolmogorov differential equations and a priori information about the intensity of transitions from state to state.Using the software implementation of the model significantly improves performance due to the ergonomics of the interface and reduced number of operations.

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