Yes / This paper presents an experimental study on an innovative composite floor system that can be demounted and deconstructed. In this system, the composite slab, formed with profiled metal decking, was connected to a steel beam via demountable shear connectors. A full-scale demountable composite floor system specimen was tested to ultimate load bearing capacity and compared with a similar non-demountable composite floor system specimen using conventional welded headed stud connectors. The experimental results and observations showed that the structural behaviour and load bearing capacity of both composite floor systems are very similar. However, the composite floor system with demountable shear connectors could be deconstructed after testing and the composite slab could be easily detached from the steel beam. The comparison and analysis presented in this paper indicated that the simple design methods currently provided in the Eurocode 4 for the welded shear connections could be used to assess the ultimate moment capacity of demountable composite floor systems.

Yes / Currently, steel reuse is only a marginal practice. To facilitate deconstruction and efficient reuse of steel components, an innovative connection system was proposed. This system adopts a ‘Block Shear Connector (BSC)’ that allows beam length to be standardised and suitable for a wide range of different sizes of the supporting members within the same planning grid. This paper presents the experimental and numerical studies of a beam-to-beam connection using BSCs. The BSC used was made from a standard universal HE / UC section and was bolted to the beams by using partial depth end plates. The experimental results provided the shear resistance, momentrotation, failure behaviour, demountability and reusability of the steel components. Further numerical simulation conducted investigated the effect of some key parameters (steel strength, thickness of BSC web, thickness of BSC flange, initial bolt stress) on the behaviour of the connections. The results obtained highlighted the demountability of this innovative bolted connection system and the reusability of structural components. / European Commission: Research Fund for Coal and Steel (RFCS-2015, RPJ, 710040)

This thesis describes design and experimental verification of three types of the wideband antenna Bow-tie antenna, Vivaldi antenna and Spiral antenna. The tracked parameters are bandwidth, input impedance, gain and directivity patterns. Next step is design of millimeter-wave horn antennas. Attention is turned to the proper construction of a wideband feeder of the horn. For the final antenna structure, a bow-tie dipole and a Vivaldi antenna were chosen. The antenna construction is aimed to provide a wide bandwidth on one hand and a high gain on the other hand.

Board-to-board connectors are used for electrically connecting one printed circuit board to another. In this thesis, a method for assessing the reliability of such connectors will be developed and tested with the goal of determining the reliability of a selection of connectors. Board-to-board connectors are widely used for connecting different electronic modules to each other, forming a modular system. Today, one of the limiting factors when it comes to modularizing electronic systems, is the lack of data on the long-term reliability of board-to-board connectors. The methods detailed in this thesis are meant to enable electronic designers to make informed decisions on connector selection when modularizing electronic systems. Modularization of electronic systems has several advantages, for example an increased first-pass yield (FPY) during assembly, and the ability to modify or replace certain parts of the system without re-spinning the entire thing. The method by which the reliability of connectors will be tested, is to continuously measure the contact resistance of the connectors during a selection of stress tests. The stress tests in question are mechanical vibration tests, thermal cycling tests, and actuation tests, all of which represent conditions that products from Hitachi Energy may be subjected to. There already exist standards on how to measure contact resistance, but those standards are not necessarily scalable to the measurement of thousands of contacts, nor are they made with the expectation that contacts can be measured during stress tests. The methods presented in this report are developed with the existing standards as basis, but have been modified in order to facilitate the measurement of thousands of contacts during stress tests. The results show that there are advantages to continuous monitoring of contact resistances during tests, as behaviors can be observed, which would not have been captured had the tests been performed conventionally. Furthermore the system which was developed forms the groundwork for a more convenient and cost effective method for testing the reliability of a large selection of board-to-board connectors. / Kontaktdon för kort-till-kort-anslutning används för att elektriskt koppla ett kretskort till ett annat. I denna avhandling utvecklas och testas en metod för att bedöma pålitligheten hos sådana anslutningar, med målet att fastställa pålitligheten hos ett urval av existerande kontaktdon. Kontaktdon för anslutning av kretskort till varandra används allmänt för att knyta ihop olika elektroniska moduler till varandra och bilda ett modulärt system. Idag är en av de begränsande faktorerna när det gäller att modularisera elektroniska system, bristen på data för långtidstålighet hos kontaktdon för kort-till-kort-anslutning. De metoder som beskrivs i denna avhandling är avsedda att möjliggöra för elektronikdesigner att fatta korrekta beslut om kontaktdonsval vid modularisering av elektroniska system. Modularisering av elektroniska system har flera fördelar, till exempel en förbättrad “first-pass yield”, FPY, när det gäller montering och möjligheten att modifiera eller ersätta vissa delar av systemet utan att behöva göra om hela systemet. Metoden som här används för att testa pålitligheten hos kontaktdon är att kontinuerligt mäta kontaktresistansen hos kontaktdonen under ett antal stresstester. De aktuella stresstesterna är mekaniska vibrationsprov, termocykeltester och aktiveringstester, vilka alla representerar vanliga situationer som Hitachi Energy’s produkter kan utsättas för. Det finns redan standarder för hur man mäter kontaktresistans, men dessa standarder är ofta inte skalbara till mätningar av tusentals kontakter samtidigt, och de är inte heller utformade för att mäta kontakter under stresstester. De metoder som presenteras i denna rapport är utvecklade med befintliga standarderna som grund, men har modifierats för att underlätta mätning av tusentals kontakter under olika stresstester. Resultaten visar att det finns fördelar med kontinuerlig övervakning av kontaktresistanser under tester, eftersom vissa beteenden kan observeras som inte skulle ha upptäckts om testerna hade utförts på ett konventionellt sätt. Dessutom utgör det system som utvecklades grunden för en mer bekväm och kostnadseffektiv metod för att testa pålitligheten hos ett stort urval av kontaktdon för kort-till-kort-anslutningar.

The increased amount of traffic combined with higher traffic loads leads to many existing bridges needing strengthening in the future to ensure their expected lifespan. This means the bridge owners will be focusing more on strengthening projects and smart solutions will be crucial for preserving a healthy bridge stock. When strengthening existing non-composite bridges (with steel girder and concrete deck) one potential method is to achieve composite action by installing shear connectors. The post-installed shear connectors prevent slip between the steel girders and the concrete. The composite action will reduce bending stresses and deflection of the bridge, due to the increase in moment of inertia and relocation of the neutral axis. Different types of shear connectors can be used for achieving composite action and each type of connector has its own installation method. The biggest distinction between the methods is how the connectors gain access to the steel girder for installation and what technique is used when installing them. This thesis presents the theory behind composite action, the current methods used for achieving composite action on existing bridges and to what extent a bridge can be strengthened by composite action. The thesis also provides a status of the existing road bridge stock around the world. The four case studies examined in this thesis have used different post-installed shear connectors to manage different strengthening problems like weight restriction, fatigue life of shear connectors and a unique problem on the Pitsund Bridge where loud bangs appeared from the bridge when truck passed in the morning. For the case study on the Pitsund Bridge an interview was conducted that explains the entire procedure of the project, from the noise problem to how the installation of coiled spring pins was performed. The bridge over Lule River at Akkatsfallen consists of two steel girders and a concrete deck. This bridge is chosen as a real case study to determine to what extent a bridge can increase its capacity by achieving composite action. The calculations are performed in accordance with the Eurocodes on both non- and full-composite action and the result is compared to the other case studies.

The thesis deals with the issue of connectors in contemporary French. The first part offers an outline of different approaches to the term connector/connecteur within Czech and Francophone linguistics. Based on the description and comparison of individual authors' approaches classified by the theoretical aspects applied, this part explains functioning of connectors not only within the logical semantic coherence relations, but also within the hierarchisation of utterance content considering the pragmatic dimension of the text. The second part of the thesis defines the term "connector" with respect to the approaches introduced above. The third part of the work deals with the characteristics and function of concessive connectors. It is based on defining the concessive relations, it describes their different aspects of meaning conditioning the relations classification within logical semantic relations in Czech and French and offers a list of linguistic means to express them and at the same time, it stresses the complex functional character of the connectors.

Forging operation is one of the most commonly used manufacturing techniques in defense industry. The products of forging operation have higher material strength when comparing to traditional manufacturing operations. Especially, for the mass production, it is a beneficial method considering metal and cost saving. The commonly used part named Fin Connector Rod in defense industry requires high material strength due to working conditions. In this thesis, manufacturing of this part by hot forging operation is accomplished after analyzing by using the finite element method. Two alternative forging processes are compared and the applicable alternative method is selected by using a finite element program. Dies are designed for applied processes. The stress distribution and the current temperature variation within the parts analyzed to evaluate the results. The fin connector rod is manufactured according to the results of the finite element analysis. It has been observed that, manufacturing of the fin connector rod by hot forging is succeeded and the waste material and cost is reduced when compared to the machining operation which is being used currently.

Further distribution of all or part of this report is subject to the Distribution Statement appearing on the front cover. / One of the global security challenges the United States faces is disaster coupled with political instability. The U.S. Military‘s ability to rapidly respond to disasters enhances regional and global security and stability. Foreign Humanitarian Assistance and Disaster Relief (FHA/DR), increasingly a mission that relies on a significant military component, focuses on the provision of goods and services such as health care, supplies necessary for survival, and infrastructure repair, with the goal of reducing the immediate human suffering. The disaster in this project‘s scenario is catastrophic flooding that occurs in one of Africa‘s most populated and wealthiest countries that threatens the stability and development of West Africa. This project, employing a systems engineering methodology, focuses on the 60 days after the disaster and the requirements to provide this assistance in the form of goods and services. Many system-of-systems architectures were developed to investigate the effectiveness of utilizing a Seabase for the primary delivery of aid. Two simulation tools, SimKit, and STELLA, were used to model and examine these architectures with the former addressing the delivery and throughput concerns while the latter focused on the satisfaction of the population and the limitation of criminal activity. Based on the results of modeling, the team provided recommendations relative to the most effective architectures in influencing the population of this coastal area as well as accomplishing the FHA/DR mission.

Recently more and more buildings of light structures have been built in Lithuania as well as in other European and world countries. Nevertheless, timber products are not widely used for floors in this share of construction market. Traditional light timber frame floors are characterized by vibrations, acoustic transmission and low fire resistance. The above-mentioned problems can be rationally solved by using timber-concrete composite (hereinafter TCC) floors. In comparison with entirely timber floors such type of floors are characterised not only by increased strength and stiffness but also by increased fire resistance and better sound insulation. In comparison with reinforced concrete floors manufactured of non-regenerative sources TCC floors are lighter and more economic. These characteristics stimulate usage of TCC floors in newly built buildings. It should also be noted that usage of timber in building structures instead of concrete or steel could substantially decrease energy demand and emission of carbon dioxide during production. In this work author presents TCC structural solution when thin-webbed beams (I-joists) used for timber floor beams instead of solid or glued rectangular beams. Thin-webbed beams are without upper flange of structural timber. Embedding in concrete a part of web of oriented strand board (hereinafter OSB) connects the OSB web and the concrete slab. This concept allows to save structural materials and production costs. Nevertheless, not so many... [to full text]

Recently more and more buildings of light structures have been built in Lithuania as well as in other European and world countries. Nevertheless, timber products are not widely used for floors in this share of construction market. Traditional light timber frame floors are characterized by vibrations, acoustic transmission and low fire resistance. The above-mentioned problems can be rationally solved by using timber-concrete composite (hereinafter TCC) floors. In comparison with entirely timber floors such type of floors are characterised not only by increased strength and stiffness but also by increased fire resistance and better sound insulation. In comparison with reinforced concrete floors manufactured of non-regenerative sources TCC floors are lighter and more economic. These characteristics stimulate usage of TCC floors in newly built buildings. It should also be noted that usage of timber in building structures instead of concrete or steel could substantially decrease energy demand and emission of carbon dioxide during production. In this work author presents TCC structural solution when thin-webbed beams (I-joists) used for timber floor beams instead of solid or glued rectangular beams. Thin-webbed beams are without upper flange of structural timber. Embedding in concrete a part of web of oriented strand board (hereinafter OSB) connects the OSB web and the concrete slab. This concept allows to save structural materials and production costs. Nevertheless, not so many... [to full text]