scholarly journals Calculation of Loads on Carrying Structures of Articulated Circular-Tube Wagons Equipped with New Draft Gear Concepts

2020 ◽  
Vol 10 (21) ◽  
pp. 7441
Author(s):  
Alyona Lovska ◽  
Oleksij Fomin ◽  
Pavel Kučera ◽  
Václav Píštěk
Keyword(s):  
Mathematical Modeling ◽  
Service Life ◽  
Dynamic Load ◽  
Computational Models ◽  
Circular Tube ◽  
Operational Efficiency ◽  
Railway Vehicles ◽  
Draft Gear

This article deals with the dynamic load and strength of the carrying structures of articulated circular-tube wagons. The study was conducted on the carrying structures of wagons equipped with new draft gear concepts. The accelerations on the carrying structures of wagons were determined using mathematical modeling. The results of modeling show that implementation of the draft gear concept can decrease the dynamic load of wagons by about 10% in comparison with that of a typical SA-3 coupler. Using the created computational models, the service life of the structure of the proposed articulated wagons was also determined. This research will encourage engineers to design modern structures of railway vehicles of higher operational efficiency.

Improving the service life of coatings during running-in

2019 ◽  
pp. 58-64
Author(s):  
I. R. Aslanyan
Keyword(s):  
Mathematical Modeling ◽  
Service Life ◽  
Contact Interaction ◽  
Phosphate Coatings ◽  
The Way

In work researches of phosphate coatings are conducted. By means of methods of mathematical modeling of contact interaction it is established that on wear of phosphate coatings the greatest influence renders their roughness. For decrease in wear of the running-in coverings applied to protection of steel products, the way on increase in service life of phosphate coatings is offered.

scholarly journals Determination of the Vertical Load on the Carrying Structure of a Flat Wagon with the 18–100 and Y25 Bogies

2021 ◽  
Vol 11 (9) ◽  
pp. 4130
Author(s):  
Oleksij Fomin ◽  
Alyona Lovska ◽  
Václav Píštěk ◽  
Pavel Kučera
Keyword(s):  
Mathematical Model ◽  
Fatigue Strength ◽  
Service Life ◽  
Dynamic Characteristics ◽  
Dynamic Load ◽  
Field Tests ◽  
Vertical Load ◽  
Mathcad Software ◽  
The Mathematical Model

The study deals with determination of the vertical load on the carrying structure of a flat wagon on the 18–100 and Y25 bogies using mathematic modelling. The study was made for an empty wagon passing over a joint irregularity. The authors calculated the carrying structure of a flat wagon with the designed parameters and the actual features recorded during field tests. The mathematical model was solved in MathCad software. The study found that application of the Y25 bogie for a flat wagon with the designed parameters can decrease the dynamic load by 41.1% in comparison to that with the 18–100 bogie. Therefore, application of the Y25 bogie under a flat wagon with the actual parameters allows decreasing the dynamic loading by 41.4% in comparison to that with the 18–100 bogie. The study also looks at the service life of the supporting structure of a flat wagon with the Y25 bogie, which can be more than twice as long as the 18–100 bogie. The research can be of interest for specialists concerned with improvements in the dynamic characteristics and the fatigue strength of freight cars, safe rail operation, freight security, and the results of the research can be used for development of innovative wagon structures.

Current trends in mathematical modeling of tumor–microenvironment interactions: a survey of tools and applications

2010 ◽  
Vol 235 (4) ◽  
pp. 411-423 ◽  
Author(s):  
Katarzyna A Rejniak ◽  
Lisa J McCawley
Keyword(s):  
Mathematical Modeling ◽  
Protein Interactions ◽  
Computational Models ◽  
Chemical Species ◽  
Tumor Stroma ◽  
Cellular Functions ◽  
Complex Interactions ◽  
Expanding Population

In its simplest description, a tumor is comprised of an expanding population of transformed cells supported by a surrounding microenvironment termed the tumor stroma. The tumor microcroenvironment has a very complex composition, including multiple types of stromal cells, a dense network of various extracellular matrix (ECM) fibers interpenetrated by the interstitial fluid and gradients of several chemical species that either are dissolved in the fluid or are bound to the ECM structure. In order to study experimentally such complex interactions between multiple players, cancer is dissected and considered at different scales of complexity, such as protein interactions, biochemical pathways, cellular functions or whole organism studies. However, the integration of information acquired from these studies into a common description is as difficult as the disease itself. Computational models of cancer can provide cancer researchers with invaluable tools that are capable of integrating the complexity into organizing principles as well as suggesting testable hypotheses. We will focus in this Minireview on mathematical models in which the whole cell is a main modeling unit. We will present a current stage of such cell-focused mathematical modeling incorporating different stromal components and their interactions with growing tumors, and discuss what modeling approaches can be undertaken to complement the in vivo and in vitro experimentation.

Modeling and Optimization on Yard Allocation Planning for Container Terminals

2010 ◽  
Vol 156-157 ◽  
pp. 540-546
Author(s):  
Lei Lin Yu ◽  
Zhi Qiang Lu ◽  
Li Feng Xi ◽  
Zhan Wan ◽  
Lin Li
Keyword(s):  
Mathematical Modeling ◽  
Heuristic Algorithms ◽  
Operational Efficiency ◽  
Experimental Results ◽  
Container Terminals ◽  
Modeling And Optimization ◽  
Container Logistics ◽  
Promising Tool ◽  
Container Shipment ◽  
Allocation Planning

The increase of container shipment causes higher demand on the seaport container terminals, container logistics and management. How to rationally allocate the limited space resources and how to improve operational efficiency, is an important subject for container terminals. In this paper, the mathematical modeling and optimization on yard allocation planning based on the mixed storage is proposed with an objective to balance the workload among different blocks and to minimize the delay of container ships. Two corresponding heuristic algorithms are developed to solve this problem. The experimental results show that the proposed algorithms are the promising tool for allocating blocks’ workload.

scholarly journals Dynamic load of the carrying structure of an articulated wagon with new draft gear concepts

2020 ◽  
Vol 33 ◽  
pp. 84-89
Author(s):  
Oleksij Fomin ◽  
Alyona Lovska ◽  
Václav Píštěk ◽  
Pavel Kučera
Keyword(s):  
Dynamic Load ◽  
Draft Gear

scholarly journals Concrete slab on elastic foundation under one axle load

2020 ◽  
Vol 313 ◽  
pp. 00010
Author(s):  
Daniela Kuchárová ◽  
Gabriela Lajčáková
Keyword(s):  
Elastic Foundation ◽  
Dynamic Load ◽  
Computational Models ◽  
Initial Conditions ◽  
Concrete Slab ◽  
Moving Load ◽  
Equations Of Motion ◽  
Dynamical Analysis ◽  
Program System ◽  
Load Effect

The paper is dedicated to the dynamical analysis of an isolated concrete slab on an elastic foundation to moving load effect of one axle load. The computational models of one axle load and a slab are mathematically described by the system of ordinary differential equations. The equations of motion are solved numerically in the environment of program system MATLAB. The plate response and dynamic load are monitored at a certain speed and certain initial conditions, depending on the properties of the elastic subgrade.

INFLUENCE OF DYNAMIC LOADING ON THE CHARACTERISTICS OF POLYMER IMPACT DAMPERS

2020 ◽  
Author(s):  
Vladimir Altuhov ◽  
Aleksey Boldyrev ◽  
Pavel Zhirov
Keyword(s):  
Mathematical Modeling ◽  
Mathematical Model ◽  
Ambient Temperature ◽  
Dynamic Loading ◽  
Loading Rate ◽  
Rolling Stock ◽  
Wear Factor ◽  
Shock Absorbers ◽  
Draft Gear ◽  
Freight Car

The article is devoted to the study of the influence of dynamic loading on the characteristics of polymer elements of shock absorbers of the rolling stock of railways and to the description of the creation of a mathematical model of their work. The results of mathematical modeling are further used to solve problems of the longitudinal dynamics of rolling stock. In the study, the initial loading rate varied, the ambient temperature and the influence of the wear factor remained unchanged. For the operating speeds of a freight car, a mathematical model of the PMKP-110 draft gear was determined.

Support for decision-making on the need to replace fire trucks in fire and rescue units

2021 ◽  
Vol 92 ◽  
pp. 106-115
Author(s):  
V. A. Aristarkhov ◽  
◽  
A. V. Rozhkov ◽  
Keyword(s):  
Mathematical Modeling ◽  
Service Life ◽  
System Analysis ◽  
Block Diagram ◽  
Operating Time ◽  
Technical Condition ◽  
Technical And Economic Analysis ◽  
Study Results ◽  
In Fire ◽  
Goals And Objectives

Introduction. A study of the fleet of fire trucks was conducted. The absence of a direct dependence of the operating time of a fire truck on its service life is confirmed on the basis of the analysis. A matrix of conditions for making a decision on the need to replace a fire truck is formed, taking into account the standard purpose of the fire truck, its service life, the actual technical condition described by the corresponding category of technical condition, as well as the date of termination of its release. A criterion for the need to replace a fire truck has been developed, as well as an algorithm for making a decision on the need to replace a fire truck in conditions of limited funding. Goals and objectives. The purpose of the article is to develop an algorithm for making a decision about the need to replace a fire truck. This goal allows us to solve the problem of justifying the need to replace the sample in the course of ensuring a given level of readiness of fire and rescue units. Methods. Methods of mathematical statistics, the theory of the importance of criteria, technical and economic analysis, mathematical modeling and system analysis were used to achieve the goal and solve the problems of the study. Results and discussion. A criterion for the need to replace a fire truck is developed, on the basis of which a block diagram of the algorithm for making a decision on the need to replace a sample is formed. Conclusion. The results obtained in the course of the work can be used in the development of programs (plans) for re-equipping fire and rescue units with modern fire trucks. Keywords: the criterion of the need for replacement, fire trucks, category by technical condition, service life

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