Dissertations / Theses on the topic 'Test Stub'

Cold-formed steel roof truss systems that use complex stiffener patterns in existing hat shape members for both top and bottom chord elements are a growing trend in the North American steel framing industry. When designing cold-formed steel sections, a structural engineer typically tries to improve the local buckling behavior of the cold-formed steel elements. The complex hat shape has proved to limit the negative influence of local buckling, however, distortional buckling can be the controlling mode of failure in the design of chord members with intermediate unbraced lengths. The chord member may be subjected to both bending and compression because of the continuity of the top and bottom chords. These members are not typically braced between panel points in a truss. Current 2001 North American Specifications (NAS 2001) do not provide an explicit check for distortional buckling. This dissertation focuses on the behavior of complex hat shape members commonly used for both the top and bottom chord elements of a cold-formed steel truss. The results of flexural tests of complex hat shape members are described. In addition, stub column tests of nested C-sections used as web members and full scale cold-formed steel roof truss tests are reported. Numerical analyses using finite strip and finite element procedures were developed for the complex hat shape chord member in bending to compare with experimental results. Both elastic buckling and inelastic postbuckling finite element analyses were performed. A parametric study was also conducted to investigate the factors that affect the ultimate strength behavior of a particular complex hat shape. The experimental results and numerical analyses confirmed that modifications to the 2001 North American Specification are necessary to better predict the flexural strength of complex hat shape members, especially those members subjected to distortional buckling. Either finite strip or finite element analysis can be used to better predict the flexural strength of complex hat shape members. Better understanding of the flexural behavior of these complex hat shapes is necessary to obtain efficient, safe design of a truss system. The results of these analyses will be presented in the dissertation.
Ph. D.

The behavior and strength of welded shear studs are subjects of ongoing study. In recent years, research has shown that the American Institute of Steel Construction (AISC) specification equations for shear stud strength are unconservative for studs placed in deck with ribs transverse to the steel beam. Twenty-four solid slab push-out tests, 93 composite slab push-out tests, and bare stud tests were performed to study the effects on stud strength of friction, normal load, position of studs in the ribs of steel deck, concrete strength, and stud properties. Stud diameters ranged from 3/8 in. to 7/8 in., deck heights ranged from 2 in. to 6 in., and both single and pairs of studs were tested. The push-out test results from this study were combined with other studies to propose a new stud strength prediction model. Three new beam tests were performed to study the effect of the stud position in the ribs of the steel deck. The results of these tests, along with 61 other beam tests, were used to verify the new stud strength prediction model. A reliability study was performed to determine resistance factors for stud strength and beam strength.
Ph. D.

A programação orientada a aspectos é uma abordagem que utiliza conceitos da separação de interesses para modularizar o software de maneira mais adequada. Com o surgimento dessa abordagem vieram também novos desafios, dentre eles o teste de programas orientados a aspectos. Duas estratégias de ordenação de classes e aspectos para apoiar o teste de integração orientado a aspectos são propostas nesta tese. As estratégias de ordenação tem o objetivo de diminuir o custo da atividade de teste por meio da diminuição do número de stubs implementados durante o teste de integração. As estratégias utilizam um modelo de dependências aspectuais e um modelo que descreve dependências entre classes e aspectos denominado AORD (Aspect and Oriented Relation Diagram) também propostos neste trabalho. Tanto o modelo de dependências aspectuais como o AORD foram elaborados a partir da sintaxe e semântica da linguagem AspectJ. Para apoiar as estratégias de ordenação, idealmente aplicadas durante a fase de projeto, um processo de mapeamento de modelos de projeto que usam as notações UML e MATA para o AORD é proposto neste trabalho. O processo de mapeamento é composto de regras que mostram como mapear dependências advindas da programação orientada a objetos e também da programação orientada a aspectos. Como uma forma de validação das estratégias de ordenação, do modelo de dependências aspectuais e do AORD, um estudo exploratório de caracterização com três sistemas implementados em AspectJ foi conduzido. Durante o estudo foram coletadas amostras de casos de implementação de stubs e drivers de teste. Os casos de implementação foram analisados e classificados. A partir dessa análise e classificação, um catálogo de stubs e drivers de teste é apresentado
Aspect-oriented programming is an approach that uses principles of separation of concerns to improve the sofware modularization. Testing of aspect-oriented programs is a new challenge related to this approach. Two aspects and classes test order strategies to support integration testing of aspect-oriented programs are proposed in this thesis. The objective of these strategies is to reduce the cost of testing activities through the minimization of the number of implemented stubs during integration test. An aspectual dependency model and a diagram which describes dependencies among classes and aspects called AORD (Aspect and Object Relation Diagram) used by the ordering strategies are also proposed. The aspectual dependency model and the AORD were defined considering the syntax constructions and the semantics of AspectJ. As the proposed estrategies should be applied in design phase of software development, a process to map a desing model using UML and MATA notations into a AORD is proposed in order to support the ordering strategies. The mapping process is composed by rules that show how to map both aspect and object-oriented dependencies. A characterization exploratory study using three systems implemented with AspectJ was conducted to validate the ordering strategies, the aspectual dependency model and the AORD. Interesting samples of stubs implementations were collected during the study conduction. The stubs were analyzed and classified. Based on these analysis and classification a catalog of stubs and drivers is presented

In traditional software development, bug detection or testing comes as an afterthought. However, bugs are difficult to detect in the later stages of software development that result in long debugging time. Usually, bugs are left out because of higher concentration on development effort, leaving lesser time for testing. Test-Driven Development (TDD) is a software development process that can reduce the debugging time by catching most of the bugs during development. The development is carried on in small and repeated steps based on test cases. However, TDD is designed to work for object-oriented languages. This thesis investigates the suitability of TDD for non-Object Oriented (OO) languages such as C. TDD can be used with C language with the help of stubbing concept. This thesis also evolves the concepts of stubs and mocks in TDD to be used with C to solve dependency related problems. Finally this thesis analyses some frameworks for TDD in C and provides the trade-offs between them.

This master's thesis describes the possibility of using a continues integration and testing in real company Logio. The result of thesis is implementation of continuous integration tools Jenkins and specific testing for the company Logio. The theoretical part deals with basic principles, techniques and tools defining continuous integration. Subsequently are describing existing tools designed for PHP programming language. The thesis also analyzes various types and possibilities of application testing. Also explains the problems in product development in company Logio, which are consequence of the need for introducing continues integration techniques. The practical part of thesis describes the implementation of a test framework PwTester and its use in continuous integration. In conclusion, the results are evaluated and outlined the possibility of extension.

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Testing has become essential to assure the quality of software products. Within the process test, unit test is performed on the smallest funcional part of the software and it aims at discovering defects in these units. JUnit is a unit test tool, which assists developers in the automation of tests and verification of results. However, much time, cost and effort are still spent to codify drivers and stubs, which most of the time jeopardizes its use. Another problem found in the unit test is the need of cases test specification in a higher level language, which is independent of any specific programming language. The Test Profile of UML 2. 0 (U2TP) solves this problem, because it allows to represent and document all artifacts used in the test process. This work aims at the fully automated generation of test drivers and stubs for JUnit from U2TP test specifications. A case study has shown that the developed algorithms correctly generated all test code, considering all elements explored in this work. The main goal of the case study was the validation of the correctness of the generated code, as well as the quantitative analysis of time consumed and number of code lines generated.
Atualmente a área de teste de software tem se tornado fundamental para garantia da qualidade dos produtos desenvolvidos. Dentro do processo de teste, o teste unitário é realizado na menor parte funcional de um software e visa descobrir defeitos nestas unidades. JUnit é uma ferramenta de apoio ao teste unitário, a qual auxilia desenvolvedores na automação dos testes e verificação dos resultados. Porém, muito tempo, custo e esforço ainda são gastos para codificar os drivers e os stubs de teste necessários a esta ferramenta, o que muitas vezes inviabiliza o seu uso. Outro problema encontrado no processo de teste unitário é a necessidade de especificação dos casos de teste em uma linguagem de mais alto nível, que seja independente de linguagem de programação. O Perfil de Teste da UML 2. 0 (U2TP) resolve este problema, pois permite representar e documentar todos artefatos utilizados no processo de teste. Esta dissertação de mestrado tem por objetivo a geração totalmente automatizada de drivers e stubs de teste para ferramenta JUnit a partir de especificações de testes modeladas com a U2TP. Um estudo de caso mostrou que os algoritmos propostos geraram corretamente todo código de teste para todos elementos explorados neste trabalho. O estudo de caso teve como principais objetivos a validação correta do código gerado, bem como uma análise quantitativa em relação ao tempo envolvido e número de linhas de código geradas.

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Atualmente a ?rea de teste de software tem se tornado fundamental para garantia da qualidade dos produtos desenvolvidos. Dentro do processo de teste, o teste unit?rio ? realizado na menor parte funcional de um software e visa descobrir defeitos nestas unidades. JUnit ? uma ferramenta de apoio ao teste unit?rio, a qual auxilia desenvolvedores na automa??o dos testes e verifica??o dos resultados. Por?m, muito tempo, custo e esfor?o ainda s?o gastos para codificar os drivers e os stubs de teste necess?rios a esta ferramenta, o que muitas vezes inviabiliza o seu uso. Outro problema encontrado no processo de teste unit?rio ? a necessidade de especifica??o dos casos de teste em uma linguagem de mais alto n?vel, que seja independente de linguagem de programa??o. O Perfil de Teste da UML 2.0 (U2TP) resolve este problema, pois permite representar e documentar todos artefatos utilizados no processo de teste. Esta disserta??o de mestrado tem por objetivo a gera??o totalmente automatizada de drivers e stubs de teste para ferramenta JUnit a partir de especifica??es de testes modeladas com a U2TP. Um estudo de caso mostrou que os algoritmos propostos geraram corretamente todo c?digo de teste para todos elementos explorados neste trabalho. O estudo de caso teve como principais objetivos a valida??o correta do c?digo gerado, bem como uma an?lise quantitativa em rela??o ao tempo envolvido e n?mero de linhas de c?digo geradas.

The aim for this project was to develop an application that would be compatible with set-top boxes, or other browser based applications, and re-search what interaction techniques that could be considered a viable substitute for a the traditional remote controller without requiring the visual attention of the viewer User test was also performed in the interest of broadly evaluating the different interaction techniques used in the application, and how the UI itself, including non visual feedback from both the sender and receiver side is perceived.

Deliberate and accidental explosions along with the heightened risk of loss of life and property damage during such events have highlighted the need for research in the behaviour of materials under high strain rates. Where an extensive body of research is available on steel and concrete structures, little to no details on how to address the design or retrofitting of wood structures subjected to a blast threat are available. Studies reported in the literature that focused on full scale light-frame wood structures did not quantify the increase in capacity due to the dynamic loading while the studies that did quantify the increase mostly stems from small clear specimens that are not representative of the behaviour of structural size members with defects. Tests on larger-scale specimens have mostly focused on the material properties and not the structural behaviour of subsystems. Advancements in design and construction techniques have greatly contributed to the emergence of taller and safer wood structures which increase potential for blast threat. This thesis presents results on the flexural behaviour of light-frame wood stud walls subjected to shock wave loading using the University of Ottawa shock tube. The emphasis is on the overall behaviour of the wall subsystem, especially the interaction between the sheathing and the studs through the nailed connection. The approach employed in this experimental program was holistic, where the specimens were investigated at the component and the subsystem levels. Twenty walls consisting of 38 mm x 140 mm machine stress-rated (MSR) studs spaced 406 mm on center and sheathed with two different types and sheathing thicknesses were tested to failure under static and dynamic loads. The experimental results were used to determine dynamic increase factors (DIFs) and a material predictive model was validated using experimental data. The implications of the code are also discussed and compared to the experimental data. Once validated, an equivalent single-degree-of-freedom (SDOF) model incorporating partial composite action was used to evaluate current analysis and design assumptions. The results showed that a shock tube can effectively be used to generate high strain-rate flexural response in wood members and that the material predictive model was found suitable to effectively predict the displacement resulting from shock wave loading. Furthermore, it was found that current analysis and design approaches overestimated the wall displacements.

L’intégrité structurelle des composants mécaniques et de leurs assemblages est un objectif majeur de conception. Les applications peuvent concerner l’aéronautique, l’automobile, le ferroviaire ainsi que les ouvrages tels que les ponts ou encore des mâts soumis à des sollicitations cycliques ou à amplitude variable. Cela amène l’ingénieur de conception à prendre en compte différents phénomènes dont celui de la fatigue, facteur dominant pouvant conduire, sous sollicitation dynamique, à la défaillance des structures ou de certaines pièces les constituant. Un outil de post-traitement a, d’une part, été développé et implémenté sous Matlab pour évaluer le niveau d’endommagement à la limite d’endurance fixée du matériau (2.106 cycles) et, d’autre part, une démarche itérative a été proposée pour le calcul de durée de vie en fatigue. Les deux critères multiaxiaux de fatigue utilisés sont le critère de Dang Van (approche de type plan critique) et celui de Zenner (approche intégrale). L’outil de post-traitement est validé par des résultats d’essais de fatigue issus de la bibliographie. Ces essais de fatigue sont réalisés sur des boulons M10 de classe de qualité 8.8. Les résultats établis sont comparés avec ceux obtenus à partir des normes existantes (Eurocode 3 et VDI 2230 notamment). Les deux critères multiaxiaux de fatigue retenus dans le cadre de ce travail sont confrontés à la banque de données des essais multiaxiaux qu’on trouve dans lalittérature. Les assemblages, boulonnés ou soudés, constituent des zones singulières dans les structures. Dans le butde mieux comprendre le comportement en fatigue du boulon dans un assemblage, un tronçon en té boulonné dans lequel le boulon peut être précontraint par serrage est modélisé par éléments finis sous le logiciel Salomé-méca. La précharge est modélisée numériquement en imposant un déplacement axial relatif entre les noeuds de l’écrou et ceux de la tige de la vis. L’effort axial FB et le moment fléchissant MB obtenus dans la vis avec le modèle numérique du tronçon en té sont validés par des solutions analytiques et des analyses expérimentales (essais de traction statique sur tronçon en té). Une étude paramétrique est menée pour analyser les influences en fatigue de la précharge dans le boulon, du diamètre de celui-ci, de son excentration par rapport à l’âme du tronçon en té et de l’épaisseur de la semelle. L’analyse s’est intéressée d’abord au niveau d’endommagement du boulon, puis à sa durée de vie en fatigue multiaxiale en utilisant l’outil de post-traitement construit dans le cadre du présent travail. Les simulations numériques de l’endommagement et de la durée de vie en fatigue montrent un comportement différent des deux approches utilisées de la fatigue multiaxiale pour la prise en compte de l’effet d’un pré-serrage important. Enfin, une campagne d’essais expérimentaux sur des tronçons en té a également été menée pour la validation du modèle numérique par rapport à l’effort axialFB et au moment de flexion MB dans le boulon
The structural integrity of mechanical components and their assemblies is a major design purpose. The applications may concern the aeronautics, the automobile, the railway as well as structures such as bridges or masts subjected to cyclic loads or to variable amplitude stress states. This leads the design engineer to take into account various phenomena, including fatigue, a dominant factor that may lead, under dynamic stress, to the failure of structures or parts of them. The mechanical components are generally subjected in service to multiaxial stress states. Taking into account the triaxiality of stress states requires the use of multiaxial fatigue criteria. They are suitable tools for assessing the material fatigue resistance against periodical stress states, especially when they are multiaxial. A fatigue post-processing tool is developed and implemented under Matlab software to assess on the one hand, the damage level at the fixed endurance limit of the material (2.106 cycles) and, on the other hand, the fatigue life up to crack initiation from an iterative fatigue calculation process. The two multiaxial fatiguecriteria used are Dang Van criterion (critical plane approach) and Zenner criterion (integral approach). Then, the fatigue post-processing tool is validated by fatigue test results from the bibliography. These fatigue tests are performed on M10 bolts of 8.8 quality class. The results are compared with those obtained from existing standards (Eurocode 3 and VDI 2230). The two multiaxial fatigue criteria used inthis work are compared and validated from the database of multiaxial tests found in the literature. Bolted or welded assemblies are singular areas in the structures. In order to better understand the fatiguebehavior of the bolt in an assembly, a tee-stub in which the bolt can be pre-stressed by clamping is modeled by finite elements under Salome-meca software. The preload is modeled numerically by imposing a relative axial displacement between the nodes of the nut and those of the rod of the screw. The FB axial force and the MB bending moment obtained in the screw with the numerical model of the tee-stub is validated by analytical solutions on the one hand and by experimental results (static tension tests on a tee-stub) on the other hand. A parametric study is conducted to analyze the fatigue influences of the bolt preload, its diameter, its location with respect to the tee-stub soul and the flange thickness. The analysis first focused on the bolt damage level, then on its fatigue life using the multiaxial fatigue post-processing tool built as part of this work. Numerical simulations of damage and fatigue life show a different behavior of the two multiaxial fatigue approaches to take into account the effect of a significanttightening. Experimental tests run on a tee-stub were also conducted to validate the numerical model with respect to the FB axial force and the MB bending moment

The master‘s thesis focuses on testing the shotcrete prepared in laboratory conditions. The main observed properties are compresive strenght of shotcrete and modulus of elasticity. The aim is assessment of methods for measuring those parameters. The calibrating correlations for strenght characteristics of shotcrete are given by obtaining the results of used methods. The shotcrete composition, amount and type of accelerating additive as well as economic aspect of using shotcrete is also assessed.

The evolving of the networking application and electronic components are pushing the bandwidth limits in the automotive domain [19]. Consequently, the car manufacturers have begun to produce more complex Electronic Control Units (ECUs) to fulfil the automotive technology evolution. Car manufacturers have used ECUs from different vendors to get the most creative features in cars [19]. These ECUs requires a standard network interface such as Ethernet which can bring significant features such as high bandwidth, low weight and full duplex communication. Nowadays, Ethernet has adapted to apply in the automotive application. Therefore, it has called for a high degree of testing to ensure the safety and interoperability between these ECUs. However, the testing of the Automotive Ethernet is facing many challenges such as finding and solving the issues as early as possible in the development process. Besides that, testing an Automotive Ethernet TCP/IP stack is a complex task, as it required an upper tester to cause the implementation of the device under the test to move to specific states. AUTOSAR has defined a standardised control protocol (Test Stub) to use it as an upper tester for executing the AUTOSAR Acceptance Test (for TCP/IP stack) [6]. This protocol has used for conducting the test cases of the TCP, UDP and IP protocols in AUTOSAR [21] [22] [23]. OPEN Alliance has specified an Automotive Ethernet ECU test specification which covers more protocols than AUTOSAR such as ARP and DHCP [7]. Consequently, potential gaps and issues may arise when using the Test Stub to conduct the test cases of the OPEN Alliance, as it initially defined for conducting the AUTOSAR Acceptance Test. This work presents the evaluation of the Test Stub in context of using it to conduct the OPEN Alliance Automotive Ethernet ECU Test. Furthermore, it will introduce a solution to overcome the potential issues and gaps which may arise after using the Test Stub (defined by AUTOSAR) to conduct the test cases of the OPEN Alliance.

碩士
國立中央大學
機械工程研究所碩士在職專班
100
Digital Set-Top Box is one of products with high precision and high unit price. It may be damaged by shock, vibration or drop during transportation. This research is aimed to study drop. The goal is make designers are able to evaluate impact of drop on the structure in early development stage. The research will use 4 groups of hard disk bracket design and experimental data to build up complete data and analysis mode of drop tests. The result found that hard disk bracket is one the most important factor of the structure design of STB. This research uses the simulation results by CAD software Pro/E and Finite Element software Abaqus to compare with the actual drop test of STB observed by drop machine to prove computer simulation technique can be a useful method in the design of hard disk bracket structure. Then we use design rules obtained by experience to modify the hard disk bracket structure. The new design has successful overcome problems happened in old design. The method of mechanical design in the article can greatly reduce damage from drop and help designers to predict product strength and dig out issues. Furthermore, it can shorten development time, lower cost, and increase competitive advantage

Cast-in-place concrete in composite with steel sections is commonly used in bridge deck constructions. The shear transfer between the concrete and steel section is achieved by shear connectors and the strength calculation of conventional shear connectors, i.e. shear studs, is provided in various design codes in North America. Due to the fact that the strength equation is largely based on experimental results, the applicability of the equation is only warranted where the design matches the experimental configuration of the test specimens. Thus, the codes specify detailing requirement for the stud height and the elevation of the reinforcement mesh in relation to the stud height. However, these requirements, in particular, the elevation of the reinforcement mesh, may be difficult to meet accurately in construction practice. The implications of not meeting the mesh requirement to the strength of the shear stud and the remedy solutions are examined in this study. An experimental program involving the test of thirty-three push-out specimens was designed and conducted with a focus on the shear studs' performance. Testing parameters included reinforcement mesh position, shear stud height, presence of stud head, shear stud spacing, and steel flange surface treatment. In addition, the performance of a new type of shear studs, referred to as adjustable studs, was also studied experimentally. The ultimate load and load vs. slip curves were presented and discussed in the forms of tables and graphs. The failure modes were noted and the relationship between the failure modes and the ultimate capacity was discussed. Ultimate loads obtained from specimens were then used to assess the efficacy of code suggested values. Results showed that depending on the elevation of reinforcement mesh, three failure modes were observed including concrete related failure, combined concrete failure and bent studs and stud shear-off from the steel flange. The elevation of the reinforcement mesh had a significant effect on the ultimate load of the specimen. As the mesh elevation increased from intercepting the stud to being in flush with the top of the stud to above the stud, the ultimate load decreased. Specimens with unheaded shear studs had lower ultimate load than specimens with headed shear studs. Flange treatment had an impact on the ultimate load, where the coating on flanges resulted in a decrease in the ultimate load. Test results also showed that the close placement of the shear studs result in a reduction on the ultimate load when the other parameters were kept the same. In the comparison between conventional and adjustable shear studs, specimens with adjustable studs shared similar failure mode to those with conventional studs, but attained on average lower load capacity. The comparison with the code suggested values showed that the code suggested value is only ensured when double-layer reinforcement mesh is used and placed at code specified elevation. A single layer mesh intercepting the studs resulted in the ultimate load slightly lower than the code value. The code values for adjustable studs are markedly higher than the experimental value, which raises the question whether the code equation for conventional studs is directly transferrable to adjustable studs.

A three dimensional nonlinear finite element model has been developed to study the behaviour of composite beams with profiled sheeting oriented perpendicular to its axis. The analysis of the push test was carried out using ABAQUS/Explicit with slow load application to ensure a quasi-static solution. Both material and geometric nonlinearities were taken into account. Elastic¿plastic material models were used for all steel components and the Concrete Damaged Plasticity model was used for the concrete slab. The post-failure behaviour of the push test was accurately predicted, which is crucial for realistic determination of shear capacity, slip and failure mode. The results obtained from finite element analysis were verified against the experimental push tests conducted in this research and also from other studies. After validation, the model was used to carry out an extensive parametric study to investigate the effect of transverse spacing in push tests with double studs placed in favourable and staggered positions with various concrete strengths. The results were also compared with the capacity of a single shear stud. It was found that shear connector resistance of pairs of shear connectors placed in favourable position was 94% of the strength of a single shear stud on average, when the transverse spacing between studs was 200 mm or more. For the same spacing, the resistance of staggered pairs of studs was only 86% of the strength of a single stud. The strength of double shear studs in favourable position was higher than that of the staggered pairs of shear connectors.

No
This paper presents the experimental and numerical investigation into the behaviour of headed shear studs in composite beams with profiled metal deck flooring. A new single-sided horizontal push test arrangement is proposed to evaluate the shear capacity of the headed shear connectors in pairs with metal deck profiled sheeting. The characteristic resistance obtained from the horizontal push test is compared with Eurocode 4. A three-dimensional finite element model was developed using general purpose finite element program ABAQUS/Explicit. The shear connector capacity, load-slip behaviour and failure modes are validated against experimental results and close correlations were obtained.

In steel¿concrete composite beams, the longitudinal shear force is transferred across the steel flange/concrete slab interface by the mechanical action of the shear connectors. The ability of the shear connectors to transfer these longitudinal shear forces depends on their strength, and also on the resistance of the concrete slab against longitudinal cracking induced by the high concentration of shear force. Most of the research in composite construction has concentrated on the more traditional reinforced concrete and metal deck construction, and little information is given on shear capacity of the headed studs in precast hollowcore slabs. In this paper, a standard push test procedure for use with composite beams with precast hollowcore slabs is proposed. Seven exploratory push tests were carried out on headed studs in solid RC slabs to validate the testing procedures, and the results showed that the new test is compatible with the results specified in the codes of practice for solid RC slabs. Once a standard procedure is established, 72 full-scale push tests on headed studs in hollowcore slabs were performed to determine the capacities of the headed stud connectors in precast hollowcore slabs and the results of the experimental study are analysed and findings on the effect of all the parameters on connectors¿ strength and ductility are presented. Newly proposed design equations for calculating the shear connectors¿ capacity for this form of composite construction are also be given.

This paper presents a numerical investigation into the behaviour of headed shear stud in composite beams with profiled metal decking. A three-dimensional finite element model was developed using general purpose finite element program ABAQUS to study the behaviour of through-deck welded shear stud in the composite slabs with trapezoidal deck ribs oriented perpendicular to the beam. Both static and dynamic procedures were investigated using Drucker Prager model and Concrete Damaged Plasticity model respectively. In the dynamic procedure using ABAQUS/Explicit, the push test specimens were loaded slowly to eliminate significant inertia effects to obtain a static solution. The capacity of shear connector, load-slip behaviour and failure modes were predicted and validated against experimental results. The delamination of the profiled decking from concrete slab was captured in the numerical analysis which was observed in the experiments. ABAQUS/Explicit was found to be particularly suitable for modelling post-failure behaviour and the contact interaction between profiled decking and concrete slabs. It is concluded that this model represents the true behaviour of the headed shear stud in composite beams with profiled decking in terms of the shear connection capacity, load-slip behaviour and failure modes.

A three-dimensional finite element model is developed, validated and used in the parametric study to investigate the influence of shear stud's position and profiled sheeting thickness on the strength, ductility and failure modes of the headed shear stud welded to the modern profiled sheeting. A total of 240 push tests were analysed with different sheeting thicknesses, positions of the shear stud in the trough, concrete strengths and transverse spacings. The results showed that the sheeting thickness influenced the shear connector resistance of studs placed in the unfavourable position more than studs placed in favourable and central positions. The strength of the shear connector placed in the unfavourable position increased by as much as 30% when the sheeting thickness was increased. The shear connector resistance of the unfavourable stud was found to be primarily a function of the strength and the thickness of the profiled sheeting rather than the concrete strength. The strength prediction equations for unfavourable and central studs were also proposed. The results suggested that the strength of the shear connector increased as the distance of the shear stud increased from the mid-height of the deck rib in the load bearing direction of the stud. The load¿slip behaviour of the studs in the unfavourable position was more ductile than the studs in the favourable position, with slip of 2-4 times higher. It was found that the increase in sheeting thickness and transverse spacing improved the ductility of the stud in unfavourable position, but had no effect on the stud in the favourable position. The failure modes suggested that the favourable and central studs failed by concrete cone failure and unfavourable studs failed by rib punching together with crushing of the narrow strip of the concrete in front of the stud.

Partition double-stud light steel framing walls provide an enhanced insulation performance when exposed to fire conditions. However, the behaviour of different configurations of such assemblies at high temperatures is still not well understood. In this sense, this study aimed to assess the fire resistance in terms of insulation requirements of double-stud light steel framing walls clad with one or two Type F gypsum plasterboards on both sides and with or without ceramic fibre cavity insulation. A series of experimental tests were conducted by subjecting small-scale specimens to ISO 834 standard fire curve and the numerical validation of each numerical model was performed using the Finite Element Method with a hybrid approach. Also, a simplified approach was proposed based on the improved design model available in the literature. The results obtained in the experimental tests revealed that a wider cavity slows the heat transfer through the wall’s cross-section, delaying the temperature rise on the unexposed gypsum plasterboard. The use of ceramic fibre cavity insulation increases substantially the fire resistance of the wall, although the heating rate of the steel studs on the exposed side is faster if compared to the specimens without cavity insulation. Moreover, concerning the specimens with the cavity partially filled with ceramic fibre, if the insulation blanket is placed towards the exposed side, enhanced fire resistance is achieved. A hybrid approach was used to carry out the numerical analysis to determine the thermal response of each model throughout fire exposure using ANSYS® Multiphysics. It was verified that using different experimental curves to represent the temperature evolution inside the cavities or insulation blankets was essential to attain improved numerical results. Also, the concept of an air thermal layer located at specific regions of the wall models led to better and more consistent results. Moreover, the modified improved design method showed consistent results when compared with the experimental values. Overall, the predicted insulation fire resistance of the model specimens agreed well with the experimental data and useful information was provided to support further numerical and experimental studies.
Las paredes de partición en acero ligero con doble montante proporcionan un rendimiento de aislamiento mejorado cuando se exponen al fuego. Sin embargo, el comportamiento de diferentes configuraciones de tales conjuntos a altas temperaturas todavía no se comprende bien. En este sentido, este estudio tuvo como objetivo evaluar la resistencia al fuego en términos de los requisitos de aislamiento de las paredes de armazón de acero ligero con doble montante revestidas con una o dos placas de yeso Tipo F en ambos lados y con o sin aislamiento de fibra cerámica en la cavidad. Se realizaron una serie de pruebas experimentales sometiendo las muestras a la curva de fuego ISO 834 y la validación numérica de cada modelo numérico se realizó utilizando el Método de los Elementos Finitos con un enfoque híbrido. Además, se propuso un enfoque simplificado basado en un modelo simplificado disponible en la literatura. Los resultados experimentales revelaron que una cavidad más ancha ralentiza la transferencia de calor a través de la sección transversal de la pared, retrasando el aumento de temperatura en el lado no expuesto. El uso del aislamiento de fibra cerámica aumenta la resistencia al fuego de la pared, aunque la velocidad de calentamiento de los montantes en el lado expuesto es más rápida en comparación con las muestras sin aislamiento en la cavidad. Además, con respecto a las muestras con la cavidad parcialmente llena de fibra cerámica, si la manta aislante se coloca hacia el lado expuesto, se logra una mayor resistencia al fuego. Utilizando ANSYS® Multiphysics, se seleccionó un enfoque híbrido para determinar la respuesta térmica de cada modelo durante la exposición al fuego. Se identificó que el uso de diferentes curvas experimentales para representar la evolución de la temperatura dentro de las cavidades o mantas aislantes es esencial para lograr mejores resultados numéricos. Además, el concepto de una capa del aire situada en regiones específicas de los modelos conduce a mejores resultados y más consistentes. Además, el método simplificado mostró resultados consistentes en comparación con los valores experimentales. En general, la resistencia al fuego en términos de los requisitos de aislamiento de los modelos coincidió bien con los datos experimentales y se proporcionó información útil para respaldar más estudios numéricos y experimentales.

The Silesian noriker is an original Czech breed of a coldblooded horse whose stud book was approved by the Ministry of Agriculture in 1995.The Silesian noricker is a strong coldblooded horse with a relatively less harmonious body structure used at present not only in agriculture and forestry but also for rehabilitation and recreation purposes. The aim of the diploma work was to work out a list of information about stud horses being in the contemporary stud as noted down in the stud book. Besides, the work focuses at proving a possible existence of the differences between the outcome of the evaluation of the exterior, performance tests and the characteristic features inherited by the descendants of the stallions. Moreover, the main aim of the work was to find out if there are individuals among stud stallions which have sufficient number of descendants being able to provide an objective evaluation of heredity control. Studbook Silesian noriker recorded 44 sires, of which only 23 subjects had descendants in breeding; the number was 266 individuals. The stud book of the SN kept files of 44 stud stallions out which only 23 individuals had descendants in stud, whose number was 266. The data for the purpose of the analysis have been based on the records in the stud books of the association of the unions of horse breeders: body measurements, evaluation of the exterior and the results of the performance tests. All the data have been presented and evaluated both in charts and graphs. In conclusion, stallions having 10 and more descendants have been evaluated in detail and the results of the latter have been compared with the average ones of SN in stud. The analysis has proved that only 68% of the whole number of descendants is represented by those written in the stud book of SN. The average body measurements were: stick withers 159,07 cm; tape withers 170,88 cm, chest perimeter 204,85 cm, shin perimeter 23,20 cm. The evaluation of the exterior showed the average result 7,47 points. The final result of the performance tests was 7, 47 points. According to the detailed analysis, out of 75 descendants only 44% belonged to SN. The Top rated offspring (exterior 7,76 and results performance tests 8,03) had of stallion Steiman 2885

Dissertação de mestrado integrado em Engenharia Civil (área de especialização em Perfil de Estruturas)
As estruturas mistas têm sido bastante utilizadas na Engenharia Civil, no contexto mundial. O comportamento misto entre uma viga metálica e uma laje de betão é conseguido mediante a utilização de conectores metálicos. A principal função dos conectores é a de transmitir as forças longitudinais de corte que se geram entre as secções de betão e de aço, quando a viga é submetida a flexão e também forças transversais ao plano da laje que podem causar a separação vertical entre a laje de betão e o perfil metálico (efeito de uplift). A presente dissertação procura abordar de uma forma explicita a modelação numérica da conexão entre o perfil metálico e a laje de betão, quando se utilizam conectores do tipo perno e betão leve. Utilizam-se elementos finitos de volume para definir todos os elementos presentes na ligação, recorrendo ao software ATENA 3D. A partir dos modelos desenvolvidos procura-se avaliar os parâmetros que são identificados como relevantes para o comportamento da conexão aço-betão. Para validar os modelos numéricos desenvolvidos, recorre-se a resultados de ensaios de tipo push-out anteriormente realizados, e são testados novos provetes de tipo push-out, com geometrias específicas, nos quais foi previamente aplicado um carregamento de valor constante durante um período pré-definido. Em todos os ensaios realizados, é possível obter a curva que relaciona força e escorregamento, ao longo do carregamento. Utilizando os resultados dos ensaios de tipo push-out obtidos por (Valente, 2007) e os resultados experimentais obtidos no âmbito desta dissertação, constroi-se e calibra-se o correspondente modelo numérico. Tendo um modelo numérico calibrado, é possível realizar um estudo paramétrico, onde se procura avaliar vários parâmetros relevantes para o comportamento da conexão. São avaliados parâmetros relacionados com as propriedades do betão como a resistência à compressão e à tração, e o módulo de elasticidade, a tensão última do aço utilizado nos conectores e a forma como o carregamento é aplicado. Comparando as curvas que relacionam força e escorregamento obtidas nos provetes ensaiados com as correspondentes curvas obtidas nos modelos numéricos desenvolvidos, é possível perceber o efeito dos parâmetros analisados na capacidade de carga, rigidez e ductilidade dos pernos.
Composite structures have been widely used in Civil Engineering, in the global context. The composite action between a steel beam and a concrete slab is accomplished with the use of steel shear connectors. The main function of these connectors is to transmit the longitudinal shears forces that arise between the concrete and steel sections, when the beam is subjected to bending forces and also transvers forces to the plane of the slab which can cause vertical separation between the concrete slab and the steel profile (uplift effect). This dissertation seeks to address the numerical modeling of the connection behavior between the steel profile and the concrete slab when using stud connectors and lightweight concrete. Finite Elements Modelling is considered to define all the elements included in the connection zone, by using the software ATENA 3D. All the parameters that are identified as relevant in the behavior of the steel to concrete connection are evaluated. Results from push-out tests previously performed and results obtained in new push-out specimens, with a specific geometry, tested within this work are used to validate the developed numerical models. In all performed experimental tests, it is possible to obtain the curve that relates force and slip along loading. The numerical model is developed and calibrated by using the results obtained in push-out tests performed by Valente (2007) and the experimental results obtained in this dissertation. With the calibrated numerical model, it is possible to conduct a parametric study, which sought to evaluate various parameters that are relevant to the connection behavior. Parameters related to concrete properties, like compressive and tensile strength, modulus of elasticity and fracture energy, ultimate strength from steel connectors’, and load application. Comparing the curves that relate force and slip obtained in the specimens tested with the corresponding curves obtained from the specimens developed with the FEM numerical models developed, it is possible to evaluate the effect of analyzed parameters on the connection’s load capacity, stiffness and ductility.