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Opotřebení kolejnic v úsecích se směrovými oblouky malého poloměru / Rail wear in track curves of small radiiSchneider, Martin January 2022 (has links)
The diploma thesis deals with a rail wear in curves with a small radius (R < 500 m), in the national corridor railway, between stations Blansko and Svitavy. The diploma thesis deals with the impact of the track gradient, the horizontal layout of the track, traffic composition, and direction of travel on the size of the horizontal and vertical rail wear. Also, the influence of rail steel grade is discussed in the diploma thesis.
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Moderní technologie pro vývoj webových aplikací a jejich výkon / Modern Technologies for Web Applications Developement and Their PerformanceSmištík, Zdeněk January 2009 (has links)
The thesis focuses on such tools for web applications development that are based on the Model-View-Controller design model. These tools include e.g. Zend Framework, Ruby on Rails, and Spring Framework. The thesis explains the functionality of the tools, their features, methods of data manipulation, and presentation of data to the users. The work contains also an application example.
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Formulation and Experimental Demonstration of Design and Control Methods for Efficient Hydraulic Architecture Based on Multi-Chamber CylindersMateus Bertolin (15343399) 04 June 2024 (has links)
<p>Amidst the increasing need to improve efficiency of fluid power systems for off-road vehicles, different architectures have been proposed in literature to reduce system throttling losses. Among the most cited ones, are architectures based on the use of common-pressure rails (CPR), which in some cases have been combined with multi-chamber cylinders to further reduce power losses. This kind of solution appears to be particularly attractive in systems with several actuators with many instances of overrunning loads, such as in earthmoving machines. In this scenario, a basic question arises concerning the maximum amount of energy that can be saved by adding extra pressure rails and/or cylinder chambers. Answering this question can be challenging given that many parameters such as cylinder areas, pressure levels and both actuator and supervisory level controls can affect the results for a given application. This work investigates energy savings potential of different architectures based on the previously mentioned concept. Based on the results of this investigation, a novel architecture combining multi-pressure rails and multi-chamber cylinders is proposed and investigated. The system is sized and simulated for the study case of an excavator. This work addresses controllers design, from the supervisory level power management control to the local cylinder actuation system. In addition, special care is taken in the area selection of the multi- chamber cylinder, with factors such as manufacturing cost and reliability being considered. The proposed design procedure allows the design of compact and efficient three-chamber cylinders on a wider range of applications. Results show the potential for power consumption reduction of up to 31% when compared to state-of-the-art machines available in the market. Additionally, the proposed cylinder design optimization allows a reduction of up to 25% in cylinder weight when compared to other design methods for multi-chamber cylinders. Within this scope, an experimental setup is designed for proof of concept of the proposed hydraulic circuit and cylinder control methods, with laboratory tests validating the feasibility of the proposed system. Test results demonstrated the ability of the proposed controller in efficiently controlling pressures within the actuator, while delivering stable speed tracking performance. Experiments also demonstrated the system capability in recovering energy and validated the expectation of obtaining hydraulic actuation with low pressure drop across control valves.</p>
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Bioflow: A web based workflow management system for design and execution of genomics pipelinesPuthige, Ashwin Acharya 11 January 2014 (has links)
The cost required for the process of sequencing genomes has decreased drastically in the last few years. The knowledge of full genomes has increased the pace of the advancements in the field of functional genomics. Computational genomics, which analyses these sequences, has seen a similar growth. The multitude of sequencing technologies has resulted in various formats for storing the sequences. This has resulted in the creation of many tools for DNA analysis. There are various tools for sorting, indexing, analyzing read groups and other tasks. The analysis of genomics often requires the creation of pipelines, which processes the DNA sequences by chaining together many tools. This results in the creation of complex scripts that glue together these tools and pass the output from one stage to the other. Also, there are tools which allow creation of these pipelines with a graphical user interface. But these are complex to use and it is difficult to quickly add the new tools being developed to existing workflows.
To solve these issues, we developed BioFlow; a web based genomic workflow management system. The use of BioFlow does not require any programming skills. The integrated workflow designer allows creation and saving workflows. The pipeline is created by connecting the tools with a visual connector. BioFlow provides an easy and simple interface that allows users to quickly add tools for use in any workflow. Audit logs are maintained at each stage, which helps users to easily identify errors and fix them. / Master of Science
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Lateral support of axially loaded columns in portal frame structures provided by sheeting railsLouw, Graeme Scott 12 1900 (has links)
Thesis (MScEng (Civil Engineering))--Stellenbosch University, 2008. / Doubly symmetric I-section columns are often utilised in portal frame construction. The sheeting (or
cladding) is carried by sheeting rails connected to the outer flange of these columns. Although it is
common practice to include the sheeting rails in the longitudinal bracing system, by connecting the
sheeting rail to the cross-bracing, designers must be wary because the connection between column
and sheeting rail will not prevent twisting of the columns cross-section. It has been shown ([11], [12],
[17]), that by including this eccentric restraint into the bracing of the column, that a torsional-flexural
buckling mode of failure can occur when the column is subjected to axial load only. It was seen that
this phenomenon is provided for in BS 5950 [18], but is not present in many other design codes of
practice, in spite of this phenomenon being relatively well known. In some cases the compression
resistance of a column can be significantly reduced when compared to that of a flexural buckled
configuration.
Previous work performed by Helwig and Yura [15] proposed specific column to sheeting rail
connections which would allow for the sheeting rails to be used as elastic torsional braces and
effectively rigid lateral braces. However, it is the objective of this investigation to determine if it is
possible to include the eccentric sheeting rails into the bracing system, even when using a relatively
simple cleat connection with only two bolts onto the sheeting rail.
The objective of the research was investigated by conducting experimental tests coupled with a series
of detailed finite element analyses. The purpose of the experimental set-up was to investigate the
behaviour of a column laterally supported on one flange by a continuous sheeting rail and to compare
it to the behaviour of a column laterally supported on both flanges by means of fly-braces (“kneebraces”).
The behaviour of the columns, as determined by the experimental tests, was validated by the finite
element analyses. The evident conclusion that can be drawn is that, for the case of a continuous
sheeting rail, connected to column simply by two bolts and a cleat, that sufficient torsional restraint is
provided to the column to prevent torsional-flexural buckling from being critical.
This result is helpful, as it means that the buckling capacity of a column can be increased four-fold by
enforcing the second flexural buckling mode instead of the first mode through utilising a continuous
sheeting rail connected to a cross-bracing system as longitudinal bracing on the columns. This can be
achieved without the need to provide any specific detailing to the column to sheeting rail connection. It
is however, recommended that further experimental work be conducted on varying lengths of column
in order to further validate the results of this work.
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Finite element analysis of tubular track systemVerlinde, Karel Jef Stefaan 12 1900 (has links)
Thesis (MScEng)--Stellenbosch University, 2012. / ENGLISH ABSTRACT: The Tubular Track (TT) railway system is a twin beam modular railway system consisting of two
reinforced concrete (RC) beams on which steel rails are continuously supported. The beams are
linked with galvanised steel gauge tie bars and continuously supported by soil foundations, and
can be used to replace conventional sleeper and ballast railway support. The TT railway system
has in the past been analysed with various analysis methods, but were found to obtain con icting
results. The con icting results means that one of the analysis methods used for the analysis and
design of TT railway sections is either an underestimation or overestimation of section displacements,
forces, and stresses; or both methods could even be incorrect. The main emphasis of this
investigation is therefore to develop and verify static and dynamic analysis methods and modeling
techniques which can be used to simulate the TT railway system accurately. The results and
models of the previous analyses are not explicitly investigated in this dissertation, but serve as
a motivation for this investigation.
The TT system is supported by several soil strata providing vertical support, but geometrically
modeling the subgrade strata in the analysis models adds a high level of complexity, and is not
feasible for general analysis where soil conditions are mostly unknown. The elastic foundation
theory is therefore used to accurately simulate the interaction between beam and foundation and
therefore su ciently simpli es the analysis models. Simpli cation of a subgrade foundation by
simulating a soil sti ness supporting the TT beam is investigated and analysed by comparing
nite element analysis (FEA) results of various soil models using parameters of four known soil
formations currently in use at TT railway sections. The FEA of the subgrade formations indicates
that there is a linear relationship between the modulus of subgrade reaction for a square
plate bearing test and a rectangular, in nitely long plate representing the subgrade support for
the TT beams. A square plate bearing test can therefore be performed on site and modi ed to
represent the actual subgrade support sti ness of the TT railway structure, whereafter it can
be used for the analysis and design of the TT system using one of the proposed analysis methods.
The analysis models used range from simple theoretical models based on elastic foundation principles,
to two-dimensional (2D) beam elements, and ultimately to complex three-dimensional (3D)
solid nite element models. The models used for the analyses are the Single and Double Beam
elastic foundation, PROKON 2D beams, ABAQUS 2D beams and ABAQUS 3D solid element
models. The alternative analysis methods considered should provide a clear indication of which
analysis methods are accurate and feasible for design of the TT system. An in-situ reference model with known de ections and design parameters speci c to a TT railway section is used to
analyse the di erent analysis methods' accuracy and validity. The Double Beam, ABAQUS 2D
and ABAQUS 3D models were found to provide very similar displacements, bending moments
and shear forces for a static analysis, whereas the PROKON and Single Beam models provide
unsatisfactory results. The PROKON beam model underestimates the bending moments and
shear forces in the rail, and overestimates bending moments and shear forces in the RC beam by
a considerably margin. This result can lead to the underdesigning of the rail which could possibly
force the RC beam to be subjected to larger maximum bending moments and shear forces than
for what it was originally designed for, thereby nullifying or possibly even exceeding the amount
for which it was overdesigned. This e ectively accelerates material fatigue, which might be the
possible cause of the small cracks in the RC beams which have been found on some TT railway
sections, which is currently being investigated. A graphical user interface of the Double Beam
method is provided for quick and e cient analysis.
Empirical methods used to simulate the dynamic nature of a railway system are often used in the
industry to simplify the dynamic loading by determining a dynamic amplitude factor (DAF) to
be applied to a static load. An implicit dynamic FEA is therefore performed to obtain the DAF
for the reference section, which is subsequently used for the comparison with in-situ de ection
results. The results of dynamic analysis validates the proposed empirical analysis method, as
the displacements obtained were very similar to actual eld test results, thereby also verifying
the accuracy of the proposed analysis methods. The sensitivity of the TT system to design
parameters is also investigated to indicate to which parameters the design is sensitive to and
where small variations of these parameters require due consideration for future and analysis of
the TT railway system. / AFRIKAANSE OPSOMMING: Die Tubular Track (TT) spoorweg stelsel is 'n dubbel balk modulêre treinspoor sisteem bestaande
uit twee gewapende beton balke waarop staal spore voortdurend ondersteun word. Die balke word
gekoppel deur gegalvaniseerde staal stawe vir laterale styfheid en word deurlopend ondersteun
deur grond fondamente, en kan gebruik word om konvensionele dwarslêer en ballast spoorweg
ondersteuning te vervang. Die TT spoorweg stelsel was in die verlede met verskeie analiseringsmetodes
ontleed, maar het teenstrydige resultate gewerf. Die teenstrydige resultate beteken
dat een van die analise metodes wat gebruik word vir die analisering en ontwerp van TT spoorweg
seksies 'n onderskatting of oorskatting van verplasings, kragte, en spannings is; of beide metodes
kan selfs verkeerd wees. Die hoofklem van hierdie ondersoek is dus die ontwikkeling en veri kasie
van statiese en dinamiese analitiese metodes en modellering tegnieke wat gebruik kan word om
die TT spoorweg stelsel akkuraat te simuleer. Die resultate en modelle van die vorige ontledings
word nie uitdruklik in hierdie proefskrif ondersoek nie, maar dien as 'n motivering van hierdie
ondersoek.
Die TT stelsel word ondersteun deur verskeie grond strata wat vertikale ondersteuning verskaf,
maar meetkundige modellering van die grond strata in die ontledingsmodelle veroorsaak 'n hoë
vlak van kompleksiteit wat nie bruikbaar is vir algemene analises waar grondeienskappe meestal
onbekend is. Die elastiese fondament teorie word daarom gebruik om die interaksie tussen die
balk en die fondament akkuraat te simuleer, en vereenvoudig dus die analitiese modelle voldoende.
Vereenvoudiging van 'n grond fondament deur 'n grond styfheid ondersteuning van die TT balk
te simuleer is ondersoek en ontleed deur die resultate van eindige element analises van verskillende
grond modelle te vergelyk. Bekende ontwerp parameters van vier bekend grondformasies
wat tans gebruik word by TT spoorweg seksies word vir hierdie analises gebruik. Die eindige
element analises van die grondformasies dui daarop aan dat daar 'n lineêre verwantskap tussen
die modulus van grond reaksie vir 'n vierkantige plaat dratoets en 'n reghoekige, oneindige lang
plaat dratoets bestaan. 'n Vierkantige plaat dratoets kan dus op terrein uitgevoer en aangepas
word om die werklike styfheid van die grond ondersteuning van die TT spoorweg sisteem voor
te stel.
Die analitiese modelle wat gebruik word wissel van eenvoudige teoretiese modelle wat gebaseer is
op elastiese fondament beginsels, twee-dimensionele (2D) balk elemente, asook komplekse driedimensionele
(3D) soliede eindige element modelle. Die modelle wat gebruik is vir die ondersoek
is die Enkel en Dubbel Balk elastiese fondament, PROKON 2D balke, ABAQUS 2D balke en ABAQUS 3D soliede element modelle. Hierdie reeks bied 'n duidelike aanduiding watter analiseringsmetodes
akkuraat en haalbaar is vir die ontwerp van die TT stelsel. 'n In-situ verwysingsmodel
met bekende de eksies en ontwerp parameters wat spesi ek is vir 'n TT spoorweg
seksie word gebruik om die akkuraatheid en geldigheid van die verskillende analitiese metodes
te analiseer. Die Dubbel Balk, ABAQUS 2D en ABAQUS 3D modelle verkry baie soortgelyke
verplasings, buigmomente en skuifkragte vir 'n statiese analise, terwyl die PROKON en
Enkel Balk modelle onbevredigende resultate verkry. Die PROKON model onderskat die maksimum
buigmomente en skuifkragte in die staal spoor, en oorskat buigmomente en skuifkragte
in die gewapende beton balk. Hierdie resultaat kan moontlik lei tot die onderontwerp van die
staal spoor en dwing moontlik vir die gewapende beton balk om blootgestel te word aan groter
buigmomente en skuifkragte as vir wat dit oorspronklik ontwerp is, en verontagsaam sodoende
moontlik die kragte waarvoor dit oorontwerp is. Dit versnel e ektief materiaal vermoeiing, wat
die moontlike oorsaak is van die klein krake wat gevind is in die gewapende beton balke op
sommige TT spoorweg seksies wat tans ondersoek word. 'n Gra ese gebruikerskoppelvlak van
die Dubbel Balk model is verskaf vir vinnige en doeltre ende ontleding.
Empiriese metodes om die dinamiese aard van 'n spoorweg-stelsel te simuleer word dikwels gebruik
in die bedryf om dinamiese belasting te vereenvoudig deur middel van die gebruik van 'n
dinamiese amplitude faktor (DAF) wat op 'n statiese belasting aangewend word. 'n Implisiete
dinamiese eindige element analise word dus uitgevoer om die DAF te ondersoek, wat daarna gebruik
word vir die vergelyking met die in-situ de eksie resultate van die in-situ verwysingsmodel.
Die resultate van die dinamiese analise bevestig dat die voorgestelde empiriese analise metode
gebruik kan word, omdat die verplasings wat verkry baie soortgelyk was aan werklike veld toets
resultate, en daardeur ook die veri ëring van die akkuraatheid van die voorgestelde analise
metodes bewerkstellig. Die sensitiwiteit van die TT stelsel vir ontwerp parameters word ook
ondersoek om aan te dui watter parameters die ontwerp voor sensitief is, en waar klein variasie
in hierdie ontwerp parameters behoorlike oorweging vereis vir die toekomstige analisering en
ontwerp van die TT spoorweg stelsel.
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R65 tipo bėgio kontaktinio suvirinimo jungties tyrimas / Research of the Flash Welding of the R65 Type Rail JointDauskurdis, Kęstutis 19 June 2014 (has links)
Šiame baigiamajame magistro darbe tiriama R65 tipo bėgio kontaktinio suvirinimo jungtis. Supažindinama su pagrindiniais mokslininkų parašytais straipsniais, bėgių kontaktinio suvirinimo tematika. Pateikiama tyrimų metodika, kurią sudaro šios dalys: apžiūrimasis paviršiaus tyrimas, ultragarsinės kontrolės tyrimas, važiuojamasis paviršiaus kiečio bandymas, sulydimo zonos nustatymas, termiškai suminkštintos zonos kiečio matavimas, mikrokietumo matavimas, mikroskopinis jungties matomosios terminio poveikio ir sulydymo zonų tyrimas, smūginio tąsumo bandymas, cheminė analizė, aširačio bandažo ir bėgio sąveikos tyrimas baigtinių elementų metodu (BEM). Išanalizuoti gauti tyrimo rezultatai, kurie įvertina suvirinimo siūlės kokybę. Pateiktos tiriamojo darbo išvados. / In the final thesis of masters degree I analyze the R65 type rail joint that were welded flash butt. Introducing with scientific articles about flash butt welding of rails. Survey methodology of the research, which consists of the following parts: visual surface review of welded joint, ultrasonic rail inspection, hardness test of upper part of the rail, fusion area research, the measurement test hardness of heat-softened area, the measurement test microhardness, microstructure research of the welded joint, impact strenght experiments, chemical analysis of welded joint, wheel-rail interaction research of the finite element method (FEM). Analyzes the results of the research, who assess the quality of weld. The conclusion is based on the results of this research.
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Sustainable Urban Rail Trails: Designing the Cross Kirkland CorridorCooledge, Mia 01 May 2013 (has links)
This thesis is a guide to building a sustainable rail-trail, wherein I focus on invasive species removal, green pavement, and creating an inviting space with the inclusion of integrated art. When the City of Kirkland, WA purchased the 5.75 mile long section of railroad going through the city, I approached city manager Kurt Triplett to ask about his plans for the corridor. He liked the idea of aiming for a sustainable trail, so I wrote a guide to building an environmentally friendly trail based on a number of prominent readings on sustainable design.
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Interaction Between Forming and the Crash Response of Aluminium Alloy S-RailsOliveira, Dino January 2007 (has links)
One of the principal energy absorbing structural components that influences the crashworthiness of a vehicle is the side-rail, which is also commonly referred to as an s-rail due to its shape that is reminiscent of an “s”. To improve the crashworthiness of a vehicle, in the wake of significant environmental pressures requiring vehicle light-weighting, the parameters that govern the crash response of the s-rail and the implications of light-weight material substitution need to be better understood.
In this work, the main parameters that govern the crash response of an s-rail and the variables that influence them were identified and assessed through a combined experimental and numerical modelling programme. In particular, the as-formed properties of aluminium alloy s-rails, due to the tube bending and hydroforming fabrication route were examined.
Tube bending, hydroforming and crash experiments were conducted to examine and assess the effects of initial tube thickness, strength, geometry, bend severity, work hardening, thickness changes and residual stresses on the crash response of the s-rail. The forming process variables, springback, thickness, strains, and force and energy response measured in the experiments were used to validate the finite element models developed herein. The validated numerical models of tube bending, hydroforming and crash provided additional insight and also allowed further investigation of the parameters governing the crash response of s-rails.
The relevant parameters governing the crash response of s-rails were isolated and the basis for a set of design guidelines, in terms of maximizing energy absorption or minimizing mass, was established. The overall size is the most influential design parameter affecting the energy absorption capability of the s-rail, followed by the initial thickness, material strength, cross-sectional geometry, bend severity and hydroforming process employed, and finally boost in bending. The most significant conclusion made based on this research is that the effects of forming history must be considered to accurately predict the crash response of the s-rail. There are additional conclusions with respect to the tube bending and hydroforming processes, as well as s-rail crash response, that will contribute to improving the design of s-rails for better crashworthiness of vehicles.
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Interaction Between Forming and the Crash Response of Aluminium Alloy S-RailsOliveira, Dino January 2007 (has links)
One of the principal energy absorbing structural components that influences the crashworthiness of a vehicle is the side-rail, which is also commonly referred to as an s-rail due to its shape that is reminiscent of an “s”. To improve the crashworthiness of a vehicle, in the wake of significant environmental pressures requiring vehicle light-weighting, the parameters that govern the crash response of the s-rail and the implications of light-weight material substitution need to be better understood.
In this work, the main parameters that govern the crash response of an s-rail and the variables that influence them were identified and assessed through a combined experimental and numerical modelling programme. In particular, the as-formed properties of aluminium alloy s-rails, due to the tube bending and hydroforming fabrication route were examined.
Tube bending, hydroforming and crash experiments were conducted to examine and assess the effects of initial tube thickness, strength, geometry, bend severity, work hardening, thickness changes and residual stresses on the crash response of the s-rail. The forming process variables, springback, thickness, strains, and force and energy response measured in the experiments were used to validate the finite element models developed herein. The validated numerical models of tube bending, hydroforming and crash provided additional insight and also allowed further investigation of the parameters governing the crash response of s-rails.
The relevant parameters governing the crash response of s-rails were isolated and the basis for a set of design guidelines, in terms of maximizing energy absorption or minimizing mass, was established. The overall size is the most influential design parameter affecting the energy absorption capability of the s-rail, followed by the initial thickness, material strength, cross-sectional geometry, bend severity and hydroforming process employed, and finally boost in bending. The most significant conclusion made based on this research is that the effects of forming history must be considered to accurately predict the crash response of the s-rail. There are additional conclusions with respect to the tube bending and hydroforming processes, as well as s-rail crash response, that will contribute to improving the design of s-rails for better crashworthiness of vehicles.
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