scholarly journals Theoretical studies of the force interaction of a three-axle vehicle with a stand with single rollers

2022 ◽  
Vol 14 (2) ◽  
pp. 52-61
Author(s):  
Іhоr Мarmut ◽  
◽  
Vitalii Kashkanov ◽  
Volodymyr Zuiev ◽  
◽  
...  
Keyword(s):  
Equations Of Motion ◽  
Thermal Conditions ◽  
Technical Condition ◽  
The Body ◽  
Power Model ◽  
Theoretical Studies ◽  
Design Features ◽  
Complex Objects ◽  
Technical Operation ◽  
Geometrical Scheme

The article discusses the issues of modeling conditions for obtaining diagnostic information about complex objects. Checking the braking and traction properties of three-axle trucks on a roller stand is considered as an example. As shown by many studies, in particular, which were carried out at the Department of Technical Operation and Service of Automobiles of the KhNADU (HADI), inertial stands provide more reliable information about the technical condition of the car. Such stands allow you to reproduce the real speed and thermal conditions of the brakes. To improve the accuracy of diagnosing a car on a roller stand, it is necessary to have an idea of the nature of the interaction of the car's wheels with the rollers. The study of the rolling of the wheels of a three-axle car bogie on the stand rollers was carried out at the Department of Technical Operation of Cars, KhNADU. However, all these studies were carried out on biaxial stands, where each bogie wheel rests on a pair of rollers. In order to exclude wheel slippage, partial braking is recommended, that is, a mode when partial force on the pedals (or pressure) is created in the system and, as a result, incomplete braking force develops in the braking mechanisms (or deceleration reaches some partial value from the full one). It is necessary to analyze the possibility of implementing full brake test modes on a roller stand by improving the layout and geometrical scheme of the stand. A power model of the system of interaction between a car and a stand has been developed, taking into account the design features of the stand and the design features of the suspension of a three-axle car. The power model of this system includes the equations of equilibrium of the body and two axles, as well as the equations of motion for the rollers and wheels of the car. Based on the results of the analysis of the acting forces in the "car-stand" system, the coefficients of the use of the load q during the brake tests of a three-axle car were determined, and the longitudinal stability of the car was also analyzed. The obtained research results allowed to improve the theory of interaction of the wheels of three-axle vehicles with single rollers of the diagnostic stand.

Investigation of the interaction of car wheels with the stand rollers during braking

2021 ◽  
Vol 13 (1) ◽  
pp. 68-77
Author(s):  
Igor Мarmut ◽  
◽  
Andriy Kashkanov ◽  
Vitaliy Kashkanov ◽  
◽  
...  
Keyword(s):  
Traffic Safety ◽  
Technical Condition ◽  
The Body ◽  
Power Model ◽  
Equilibrium Equations ◽  
Design Features ◽  
Complex Objects ◽  
Passenger Cars ◽  
Wheel Drive ◽  
Four Wheel Drive

The article discusses the issues of modeling conditions for obtaining diagnostic information about complex objects. As an example, the study of the braking qualities of four-wheel drive cars on an inertial roller stand is considered. Diagnosing the technical condition of cars from the point of view of traffic safety is one of the most important problems. This is especially important for systems whose technical condition affects traffic safety: especially braking systems. Foreign and domestic experience testifies to the effectiveness of instrumental control. The diagnostic equipment includes roller stands, on which you can check the braking properties of cars. As shown by many studies, in particular, carried out at the Department of Technical Operation and Service of Automobiles, KhNADU (HADI), inertial stands provide more reliable information about the technical condition of the car. Such stands allow you to reproduce the real speed and thermal modes of the brakes (especially those equipped with ABS). To improve the accuracy of diagnosing a car on a roller stand, it is necessary to have an idea of the nature of the interaction of the car wheels with the rollers. The studies of wheel rolling on the stand rollers have been carried out by many authors since the 80s of the last century. However, all these studies were carried out on uniaxial stands and for mono-drive vehicles. Nowadays, a large number of passenger cars have four-wheel drive. Rolling of the wheels of such cars on rollers and their interaction has practically not been studied. Therefore, a return to the study of this issue is relevant. A power model of the system of interaction between the car and the stand has been developed, taking into account the design features of the stand and the design features of the car's suspension. The power model of the system under consideration contains the equilibrium equations of the body and two bridges and the equations of motion of the rollers and wheels of the car. Based on the results of the analysis of the acting forces in the "car-stand" system, the braking moments on the wheels M and the coefficients of the use of the load q during the braking tests of a 4x4 vehicle were determined. The obtained research results allowed to improve the theory of interaction of a car wheel with the rollers of an inertial diagnostic stand.

ANALYSIS OF THE CREW PART OF THE LOCOMOTIVE TEM23 AND PROPOSALS FOR ELIMINATION OF DISADVANTAGES

2020 ◽  
Author(s):  
Dmitriy Antipin ◽  
Vladimir Vorobev ◽  
Denis Bondarenko ◽  
Gennadiy Petrov
Keyword(s):  
Vertical Plane ◽  
The Body ◽  
Diesel Locomotive ◽  
Design Features ◽  
Bogie Frame ◽  
Spring Suspension ◽  
In Series

The analysis of the design features of the bogie of the TEM23 shunting diesel locomotive is carried out. In the process of analysis, the directions of its improvement are determined. It is proposed to rotate the bogie frame in the vertical plane by reducing the body supports to two and using a pivot with low lowering, equip the bogies with pneumatic spring suspension in the form of two corrugations installed in series with shortened suspension springs. The proposed options for improving the undercarriage of a diesel locomotive will increase the competitiveness of products and reduce costs

scholarly journals Efficiency and Teamwork in Emergency Departments: Perception of Staff on Design Interventions

2021 ◽  
pp. 193758672110231
Author(s):  
Sahar Ahmadpour ◽  
Sara Bayramzadeh ◽  
Parsa Aghaei
Keyword(s):  
Work Environment ◽  
Emergency Departments ◽  
Online Survey ◽  
The Body ◽  
Healthcare Outcomes ◽  
Design Strategies ◽  
Design Features ◽  
Staff Members ◽  
Enhance Efficiency ◽  
Efficient Work

Objectives: The goal of this study is twofold: (1) identifying design strategies that enhance efficiency and support teamwork in emergency departments (EDs) and (2) identifying design features that contribute to the spread of COVID-19, based on staff perception. Background: Due to increasing ED visits annually, an efficient work environment has become one of the main concerns in designing EDs. According to the literature, an efficient work environment and teamwork improve healthcare outcomes and positively impact staff satisfaction. During the COVID-19 pandemic, EDs faced various changes such as workflow and space usage. Few studies explored staff perceptions about the influence of design features on efficiency, teamwork, and the COVID-19 spread. Method: An online survey with 14 open- and closed-ended questions was distributed among ED staff members to collect data about unit design features that impact efficiency, teamwork, and the COVID-19 spread. Results: The central nursing station was one of the preferred configurations that increased efficiency and teamwork in EDs. Decentralizing disposal rooms in small-size EDs and decentralizing the medication room in large-size EDs with more than 65 exam rooms can decrease staff walking steps. Flexibility to expand treatment spaces on demand, one-way track circulation path, and changing the air pressure in COVID-19 treatment areas were some of the staff suggestions for future EDs. Conclusion: The findings of this study contribute to the body of knowledge that EDs’ physical environments can impact efficiency and teamwork among staff and, consequently, healthcare outcomes. Compartmentalization of the ED layout can reduce the spread of COVID-19.

Application of neural network expert systems for monitoring, diagnostics and forecasting of technical condition of aircraft engines

2020 ◽  
pp. 51-59
Author(s):  
Д.О. Пушкарёв
Keyword(s):  
Neural Network ◽  
Expert Systems ◽  
Gas Turbine ◽  
Technical Condition ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Fuzzy Interference System ◽  
Interference System ◽  
Monitoring And Diagnostics ◽  
Technical Operation

Рассматривается применение нейросетевых экспертных систем в области контроля, диагностики и прогнозирования технического состояния авиационных ГТД на основе нечеткой логики. Показана методика для решения таких задач в области технической эксплуатации авиационной техники совместно с использованием фаззи-интерференсной системы программы MATLAB. Используя статистические данные о работе двигателя формируется экспертная система на основе нейронной сети позволяющая осуществлять контроль и диагностику ГТД, а также прогнозировать дальнейшее техническое состояния анализируемого двигателя. The application of neural network expert systems in the field of monitoring, diagnostics and forecasting of the technical condition of aviation gas turbine engines based on fuzzy logic is considered. The technique for solving such problems in the field of technical operation of aircraft and using the fuzzy-interference system of the MATLAB program is shown. Using statistical data on the operation of the engine, an expert system is based on the fundamental of a neural network that provide monitoring and diagnostics of gas turbine engines, as well as predicting the further technical condition of the analyzed engine.

Numerical modelling of swirling momentumless turbulent wake dynamics

2018 ◽  
pp. 37-48
Author(s):  
Андрей Геннадьевич Деменков ◽  
Геннадий Георгиевич Черных
Keyword(s):  
Numerical Simulation ◽  
Mathematical Model ◽  
Mathematical Models ◽  
Equations Of Motion ◽  
Turbulent Wake ◽  
The Body ◽  
Jet Flows ◽  
Reynolds Stresses ◽  
Bodies Of Revolution ◽  
Averaged Equations

С применением математической модели, включающей осредненные уравнения движения и дифференциальные уравнения переноса нормальных рейнольдсовых напряжений и скорости диссипации, выполнено численное моделирование эволюции безымпульсного закрученного турбулентного следа с ненулевым моментом количества движения за телом вращения. Получено, что начиная с расстояний порядка 1000 диаметров от тела течение становится автомодельным. На основе анализа результатов численных экспериментов построены упрощенные математические модели дальнего следа. Swirling turbulent jet flows are of interest in connection with the design and development of various energy and chemical-technological devices as well as both study of flow around bodies and solving problems of environmental hydrodynamics, etc. An interesting example of such a flow is a swirling turbulent wake behind bodies of revolution. Analysis of the known works on the numerical simulation of swirling turbulent wakes behind bodies of revolution indicates lack of knowledge on the dynamics of the momentumless swirling turbulent wake. A special case of the motion of a body with a propulsor whose thrust compensates the swirl is studied, but there is a nonzero integral swirl in the flow. In previous works with the participation of the authors, a numerical simulation of the initial stage of the evolution of a swirling momentumless turbulent wake based on a hierarchy of second-order mathematical models was performed. It is shown that a satisfactory agreement of the results of calculations with the available experimental data is possible only with the use of a mathematical model that includes the averaged equations of motion and differential equations for the transfer of normal Reynolds stresses along the rate of dissipation. In the present work, based on the above mentioned mathematical model, a numerical simulation of the evolution of a far momentumless swirling turbulent wake with a nonzero angular momentum behind the body of revolution is performed. It is shown that starting from distances of the order of 1000 diameters from the body the flow becomes self-similar. Based on the analysis of the results of numerical experiments, simplified mathematical models of the far wake are constructed. The authors dedicate this work to the blessed memory of Vladimir Alekseevich Kostomakha.

The Global Motion of a Rigid Body Subject to Periodic Body-Fixed Torques

1995 ◽  
Author(s):  
X. Tong ◽  
B. Tabarrok
Keyword(s):  
Rigid Body ◽  
Equations Of Motion ◽  
Melnikov Method ◽  
The Body ◽  
Body Motion ◽  
Heteroclinic Orbits ◽  
Coordinate Frame ◽  
Global Motion ◽  
Stable And Unstable Manifolds ◽  
Body Subject

Abstract In this paper the global motion of a rigid body subject to small periodic torques, which has a fixed direction in the body-fixed coordinate frame, is investigated by means of Melnikov’s method. Deprit’s variables are introduced to transform the equations of motion into a form describing a slowly varying oscillator. Then the Melnikov method developed for the slowly varying oscillator is used to predict the transversal intersections of stable and unstable manifolds for the perturbed rigid body motion. It is shown that there exist transversal intersections of heteroclinic orbits for certain ranges of parameter values.

scholarly journals Privacy of Clinical Research Subjects: An Integrative Literature Review

2018 ◽  
Vol 14 (1) ◽  
pp. 33-48 ◽  
Author(s):  
Sanna-Maria Nurmi ◽  
Mari Kangasniemi ◽  
Arja Halkoaho ◽  
Anna-Maija Pietilä
Keyword(s):  
Clinical Research ◽  
Privacy Protection ◽  
Personal Data ◽  
Comparison Method ◽  
Health Data ◽  
The Body ◽  
Social Benefits ◽  
Theoretical Studies ◽  
Research Practice ◽  
Research Subjects

With changes in clinical research practice, the importance of a study-subject’s privacy and the confidentiality of their personal data is growing. However, the body of research is fragmented, and a synthesis of work in this area is lacking. Accordingly, an integrative review was performed, guided by Whittemore and Knafl’s work. Data from PubMed, Scopus, and CINAHL searches from January 2012 to February 2017 were analyzed via the constant comparison method. From 16 empirical and theoretical studies, six topical aspects were identified: the evolving nature of health data in clinical research, sharing of health data, the challenges of anonymizing data, collaboration among stakeholders, the complexity of regulation, and ethics-related tension between social benefits and privacy. Study subjects’ privacy is an increasingly important ethics principle for clinical research, and privacy protection is rendered even more challenging by changing research practice.

MULTIBODY DYNAMIC MODELING AND FLUTTER ANALYSIS OF A FLEXIBLE SLENDER VEHICLE

2012 ◽  
Vol 12 (06) ◽  
pp. 1250049 ◽  
Author(s):  
A. RASTI ◽  
S. A. FAZELZADEH
Keyword(s):  
Differential Equations ◽  
Rigid Body ◽  
Dynamic Modeling ◽  
Equations Of Motion ◽  
The Body ◽  
Elastic Deformations ◽  
Strip Theory ◽  
Multibody Dynamic ◽  
Flutter Analysis ◽  
Rigid Body Motions

In this paper, multibody dynamic modeling and flutter analysis of a flexible slender vehicle are investigated. The method is a comprehensive procedure based on the hybrid equations of motion in terms of quasi-coordinates. The equations consist of ordinary differential equations for the rigid body motions of the vehicle and partial differential equations for the elastic deformations of the flexible components of the vehicle. These equations are naturally nonlinear, but to avoid high nonlinearity of equations the elastic displacements are assumed to be small so that the equations of motion can be linearized. For the aeroelastic analysis a perturbation approach is used, by which the problem is divided into a nonlinear flight dynamics problem for quasi-rigid flight vehicle and a linear extended aeroelasticity problem for the elastic deformations and perturbations in the rigid body motions. In this manner, the trim values that are obtained from the first problem are used as an input to the second problem. The body of the vehicle is modeled with a uniform free–free beam and the aeroelastic forces are derived from the strip theory. The effect of some crucial geometric and physical parameters and the acting forces on the flutter speed and frequency of the vehicle are investigated.

scholarly journals Field Study Of A Radiant Heating System For Sleep Thermal Comfort And Potential Energy Saving

2021 ◽  
Author(s):  
Christopher L. K. Wang
Keyword(s):  
Potential Energy ◽  
Thermal Comfort ◽  
Energy Saving ◽  
Energy Savings ◽  
Thermal Environment ◽  
Residential Buildings ◽  
Thermal Conditions ◽  
Heating System ◽  
The Body ◽  
Radiant Temperature

As sleep is unconscious, the traditional definition of thermal comfort with conscious judgment does not apply. In this thesis sleep thermal comfort is defined as the thermal condition which enables sleep to most efficiently rejuvenate the body and mind. A comfort model was developed to stimulate the respective thermal environment required to achieve the desired body thermal conditions and a new infrared sphere method was developed to measure mean radiant temperature. Existing heating conditions according to building code conditions during sleeping hours was calculated to likely overheat a sleeping person and allowed energy saving potential by reducing nighttime heating set points. Experimenting with existing radiantly and forced air heated residential buildings, it was confirmed that thermal environment was too hot for comfortable sleep and that the infrared sphere method shows promise. With the site data, potential energy savings were calculated and around 10% of energy consumption reduction may be achieved during peak heating.

scholarly journals TECHNICAL CONDITION OF CORRUGATED METAL TRANSPORT STRUCTURES

2021 ◽  
pp. 38-50
Author(s):  
J. J. LUCHKO ◽  
V. V. KOVALCHUK
Keyword(s):  
Bearing Capacity ◽  
Technical Condition ◽  
The Body ◽  
Soil Environment ◽  
Metal Structures ◽  
Advantages And Disadvantages ◽  
Methods Of Calculation ◽  
Analysis And Synthesis ◽  
The Impact ◽  
Corrugated Metal

Purpose. The purpose of the work is to establish the real technical condition of transport structures made of corrugated metal structures on the basis of the analysis of scientific and technical sources.And to analyze the experience of operation of metal corrugated structures in the soil environment and to form and generalize the problems of ensuring the reliability and durability of structures made of metal corrugated structures in the conditions of operation on railways and highways of Ukraine. Methodology. To achieve this goal, a review of scientific and technical sources and regulations of different countries on the technical condition of transport facilities in Ukraine was conducted. In particular, data on the distribution of bridges and pipes made of corrugated metal structures by mode of transport are given. It is shown that the development and implementation of new technologies for the repair of existing defective pipes and small bridges, both on the railways and highways of Ukraine is a very important issue. A thorough analysis of the experience of operation of corrugated metal structures in the soil environment in different countries was conducted. Data on the main inadmissible defects of pipes and the reasons of their development are given. CMS' (corrugated metal structures) corrosion and other defects are given. A number of examples of overpass defects, collapse of bridges and structures with MCS in operation are presented. The qualitative indicators of metal corrugated structures, their advantages and disadvantages are also considered, the problems and the analysis of ensuring the reliability and durability of the structures with CMS in the conditions of operation on the railways and highways of Ukraine are formulated. Findings. An analysis of domestic and foreign scientific and technical sources on the technical condition of transport facilities in Ukraine was conducted. In particular, the experience of operation of corrugated metal structures in different countries of the world is studied and generalized. The analysis and synthesis of problems of ensuring the reliability and durability of buildings with CMS in the conditions of operation on the railways and highways of Ukraine. Originality. As a result of the analysis of the technical condition of transport facilities operated on railways and highways of Ukraine, it was found that about 15 % of transport facilities – small and medium bridges and culverts on Ukrainian railways and about 45 % of transport facilities on Ukrainian roads have unacceptable defects and require immediate repair and replacement. Also, it was established on the basis of research that there are no methods for assessing the load-bearing capacity of transport facilities with CMS in the presence in the body of the embankment of the railway or highway metal corrugated structures with a diameter greater than 6 m. It was determined that standards don't include regulations on design and monitoring of CMS on railway tracks. Practical value. On the basis of these data it was possible to offer directions of theoretical and experimental research and methods of calculation, tests of CMS and diagnostics of a technical condition of transport structures with CMS. In particular, the measurement of the impact of the environment on the bearing capacity of the CMS and the measurement of residual deformations of the corrugated metal pipe on the railway track. Execution of the analysis and synthesis of methods of calculation of transport constructions with CMS will lead to improvement of methods of calculation of CMS.

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