I dagens läge har energifrågorna väckt ett stort intresse i samhället. Nu fokuseras det mer på att bygga energisnålare hus. En betydande faktor som påverkar energiförbrukningen i våra hus är köldbryggor. De uppstår då ett material med dålig värmeisolering bryter igenom ett material med bättre värmeisolering. Köldbryggor är nästan omöjligt att undvika, dock går alltid att reducera. I praktiken är det ofta inte möjligt att helt undvika köldbryggor, men det finns många olika möjligheter att minska köldbryggeffekten kraftigt. Detta eftersträvas för att uppnå lägre energikostnader eftersom köldbryggor kan medföra en betydande ökning av värmeförlusten. Avgränsningen för detta examensarbete framgår av titeln Köldbryggors inverkan på isoleringsegenskaper för sandwichelement, anslutning mellan fönster och yttervägg. Den främsta metoden som används för att åstadkomma resultatet är PC-programmet HEAT2, men litteraturstudier har också använts. HEAT2 är ett tvådimensionellt värmeflödesprogram, som beräknar den värmemängd som leds genom konstruktionsdelen. Den bygger på att dela in byggnadsdelen i ett rutnät (mesh). Ju fler rutor den blir uppdelad i, desto noggrannare resultat, men beräkningen blir samtidigt mer tidskrävande att utföra. En särskild analys gjordes med och utan den dränerande skyddsplasten i fönstrets överkant då materialet skär igenom värmeisoleringen vid betongklacken. Plasten har mångfaldigt högre värmekonduktivitet än värmeisoleringen, men den är bara 1 mm tjock. Beräkningsresultaten visar att skyddsplasten gav en betydande skillnad. / Currently, the energy issues brought a lot of interest in the community. Now is the focus more on building energy-efficient houses. A significant factor influencing energy consumption in our buildings is thermal bridges. They occur when a material with poor thermal insulation breaks through a material with better insulation. In practice it is often not possible to avoid thermal bridges completely, but there are many different options to reduce the thermal bridge effect significantly. This is desirable in order to achieve lower energy costs because thermal bridges can lead to a significant increase in the heat losses. The limitation of this degree project is evident from the title Thermal bridges impact on the insulation properties of sandwich panels, the connection between the windows and external walls The primary means used to achieve the results is the HEAT2 PC-program, but literature studies were also used. HEAT2 is a two-dimensional heat flow program that calculates the amount of energy passed through the part of the construction. It is based on the allocation of the construction into a mesh, i.e. a grid. The more the mesh is divided into the more accurate the results, but the calculations are at the same time more time consuming to perform. A separate analysis was done with and without the draining protective plastic in the window's top edge where the material is passing through the thermal insulation at the concrete heel. The plastic has many orders of magnitude higher thermal conductivity than the thermal insulation, but it is only 1 mm thick. The calculation results show that the plastic caused a significant difference.

La modélisation du comportement vibroacoustique en flexion des structures sandwich est devenue aujourd’hui de plus en plus d’un grand intérêt dans les différents secteurs industriels. Cette tendance est principalement due aux propriétés mécaniques avantageuses des structures sandwich. L’un des principaux avantages de ce type de structures réside principalement dans le rapport rigidité-poids élevé. En revanche, acoustiquement la diminution de la masse du panneau avec une rigidité élevée conduit à un confort acoustique insatisfait. Pour cette raison, il y a une demande croissante pour des approches de modélisation du comportement vibroacoustique des structures sandwich avec une précision maximale. La présente thèse propose une approche méso-macro basée sur une méthode numérique pour la prédiction des caractéristiques dynamiques des structures sandwich. La méthode est principalement utilisée pour résoudre le problème de transparence acoustique considéré dans ce projet de thèse. Le travail présenté porte principalement sur la topologie du coeur du sandwich pour traiter le problème abordé. Le principal avantage du modèle proposé réside dans les effets du cœur prises en compte telle que l’effet du cisaillement et celle de l’orthotropie du panneau sandwich. L’approche de modélisation proposée est basée sur la méthode des éléments finis ondulatoire, qui combine la méthode des éléments finis classique et la théorie des structures périodiques. La structure sandwich a été modélisée comme un guide des ondes tridimensionnelles qui garde absolument les informations à l’échelle mésoscopique du panneau modélisé. La fréquence de transition définie la fréquence à laquelle le cisaillement du coeur devient important. Cette fréquence spéciale a été identifié via deux méthodes numériques. Une expression de transmission acoustique à travers un panneau sandwich a également été dérivée. Ensuite, une étude paramétrique a été menée dans le but de révéler l’effet des différents paramètres géométriques sur les indicateurs vibroacoustiques. / Prediction of the flexural vibroacoustic behavior of honeycomb sandwich structures in the low-mid frequency is nowadays becoming of high interest in different industrial sectors. This trend is mainly owing to the advantageous mechanical properties of the sandwich structures. One of the main advantages of this kind of structures lies principally in the high stiffness-to-weight ratio. Even though, acoustically the decrease of the panel mass with a high stiffness leads to an unsuitable acoustic comfort. For this reason, there is an increasing demand for approaches modeling the vibroacoustic behavior of the sandwich structures with a maximum accuracy. The present thesis deals with a meso-macro approach based on a numerical method for modeling the vibroacoustic behavior of sandwich structures. The modeling description is mainly used to address the acoustic insulation problem considered in the thesis. The presented work focuses on the topology of the sandwich core to treat the addressed problem. The main advantage of the proposed model is that it takes into account the core shear and panel orthotropic effects. The modeling approach suggested here is based on the wave finite element method (WFE method), which combines the standard finite element method and the periodic structure theory. The sandwich structure has been modeled as a tridimensional waveguide which holds absolutely the meso-scale information of the modeled panel. The transition frequency, which indicates the frequency at which the core shear becomes important, was identified via two different numerical methods. An expression of the acoustic transmission for an equivalent isotropic sandwich panel was also derived. A parametric study was then conducted with a goal of revealing the effect of the geometric parameters of the sandwich core on the vibroacoustic indicators.

Sandwichplatten sind effiziente Leichtbauelemente. Sie werden im Fahrzeugbau, in der Luft- und Raumfahrt, im Werkzeugmaschinenbau und überall dort, wo es auf geringe bewegte Massen ankommt, eingesetzt. Sandwichplatten sind oft Halbzeuge. Sandwichbauteile haben oft einen aufwendigen Herstellungsprozess, der eine Wärmebehandlung, die höhere Genauigkeiten ausschließt, beinhaltet. Aus diesen Gründen ist es oft sinnvoll, Inserts erst im Nachhinein in die fertige Sandwichplatte bzw. in das fertige Sandwichbauteil einzusetzen. Diese Inserts haben unterschiedliche Aufgaben. Sie dienen z.B. der Aufnahme von Schrauben, Bolzen und Lagern. Die vorgestellte Verbindung entspricht durch ihre spezielle Geometrie den hohen Anforderungen für Verbindungselemente in den genannten Gebieten hinsichtlich Genauigkeit und Stabilität. Es wird der Konstruktionsprozess eines Inserts für Sandwichplatten aus CFK- Verbundmaterial beschrieben. Ausgehend von einer patentierten Lösung der Autoren findet eine schrittweise Produktverbesserung bis hin zu einem einsatzfähigen Prototypen statt. Durch die Insertverbindung können für den Maschinenbau erforderliche Genauigkeiten nun mit CFK- Halbzeugen umgesetzt werden. Die Anwendung dieses Leichtbaupotentials führt zur Energieeinsparung und zum Transfer von CFK- Anwendungen in den Maschinenbau.

Building is designed to investor's business in a driving school and auto service of cars in Uherský Brod. It's consist of two related objects: SO01 and SO02. SO01 - two storey brick building of driving school and auto service. Construction system is Porotherm. Roof construction is single layer flat roof. SO02 - steel hall used for cars service. Object is sheathed of sandwich panels Kingspan.

This thesis describes the design of a multipurpose sports hall in Pribram. The sports hall is situated in the town of Pribram II. The aim of this work is to propose bearing structure with dimensions 49 x 28 halls has a background in the shape of L in the level of ± 0.000. Maximum height of the hall is 14 meters.Structure of the hall consists of arched trusses in 7 m grid supported by steel columns. This is a column support system. The building is based on the footings. Ensure stability bracing. Perimeter and roof cladding consists of sandwich panels.

The subject of my master´s thesis is the proces of structurylly-technical part of the project documentation of a new building of sports centre in Polná. Designed building is located in the western part of the field by gently sloping terrain. The building is divided into two patrs of the building. Sports hall and facilities for athletes and spectators. The sports hall has one floor and is partially below the surface. The sports hall is covered with a gable roof. Roof cladding is made of sandwich panels. Facilities has two floors and is covered by a flat roof. This is a new building, which are used in conventional building materials. The main fittings include brick and reinforced concrete.

Master thesis Energy centre - selected parts of building technology project is solving problems connected with technological issues from the construction work supplier point of view. This thesis concerns such a parts as financial, timing and preparations are. Material used as a base was a master thesis of the student from Civil engineering department.

aus dem Inhalt: „Die im Teilprojekt Sobek (siehe S. 626 ff .) entwickelte gefrorene Sandschalung zur abfallfreien Herstellung von Betonbauteilen wurde im Rahmen des BMBF-geförderten Konsortiums Carbon Concrete Composite – C3 für die Herstellung dünnwandiger und gekrümmter Sandwichelemente weiterentwickelt. Der vorliegende Kurzbericht fasst die Forschungsergebnisse des Projekts C3Sandwich zusammen. Eine ausführliche Beschreibung der Arbeiten wurde in [1] veröffentlicht....” / from teh content: „Within the framework of the BMBF-funded consortium Carbon Concrete Composite – C3, the research on sand formwork for the waste-free production of concrete components (TP Sobek, p. 626 seq.) was further advanced towards the production of thin-walled and curved sandwich elements. This report summarizes the research results of the project C3Sandwich. A detailed description of the work was published in [1]....”

[pt] O presente trabalho propõe-se a analisar o comportamento mecânico de painéis sanduíche constituídos por duas camadas externas de compósitos cimentícios reforçados com fibras naturais, separadas por um núcleo de concreto celular autoclavado (CCA). Cada placa de material compósito foi moldada diretamente sobre a superfície de um bloco de CCA, por meio da disposição manual de três camadas unidirecionais de fibras longas de curauá. Visando prover maior durabilidade ao compósito, desenvolveu-se uma matriz com baixo teor de hidróxido de cálcio, substituindo uma parcela do cimento por materiais pozolânicos. Ensaios de caracterização da matriz, dos filamentos de curauá e dos blocos de CCA foram realizados para a obtenção de suas propriedades independentes. Os compósitos foram submetidos a ensaios de arrancamento do tecido, tração direta e flexão a quatro pontos para a avaliação de diferentes aspectos de seus mecanismos de fissuração, resistência e capacidade de deformação. Zonas de carregamento foram indicadas em cada caso para demonstrar o comportamento padrão dos compósitos. Os painéis sanduíche, por sua vez, foram analisados em termos de interface, por meio de ensaios de aderência e micrografias da superfície de transição dos materiais, e de desempenho mecânico, por ensaios de flexão a quatro pontos cíclicos e monotônicos. Esses últimos forneceram a rigidez, capacidade de carga e deflexão dos painéis sanduíche, tal como as principais propriedades de seus elementos: para o núcleo, a resistência ao cisalhamento e o módulo de cisalhamento, e para as lâminas, a resistência à compressão e à tração. Os ensaios cíclicos testaram a resistência do material a séries de carregamento-descarregamento, enquanto ensaios de aderência foram utilizados para verificar a interface entre os compósitos laminados e o núcleo de CCA. Os resultados indicaram um desempenho satisfatório dos painéis sanduíche, uma vez que os compósitos foram capazes de lhes fornecer um comportamento de strain/deflection hardening, aumentando sua resistência e tenacidade. A adesão entre lâminas-núcleo mostrou-se eficaz, de maneira que os diferentes materiais compreendidos demonstraram interação adequada entre si, bem como propriedades complementares. Dentre os objetivos desse trabalho, encontra-se o desenvolvimento de um material sustentável, leve, resistente e tenaz, de modo que constitua uma alternativa promissora e de baixo custo a aplicações de Engenharia. / [en] This present work aims to analyze the mechanical behavior of sandwich panels consisting of two outer layers of natural fiber-reinforced cementitious composites separated by a core layer of autoclaved aerated concrete (AAC). The molding of each composite layer was made directly on the surface of an AAC block, by manually arranging three layers of long unidirectional aligned curauá fibers in the mortar. In order to increase the composite durability, a matrix with a low content of calcium hydroxide was developed, where the Portland cement was partially replaced by pozzolanic materials. Characterization tests of the matrix, the curauá filaments and the AAC blocks were performed to obtain their independent properties. The composites were submitted to fabric pull-out tests, direct tensile tests and four-point bending to evaluate different aspects of their cracking mechanisms, strength and deformation capacity. Loading zones were indicated in each case to demonstrate the standard composite behavior. The sandwich panels, on the other hand, were analyzed in terms of interface, through pull-off tests and SEM images of the materials transition surface, and mechanical performance, by means of cyclic and monotonic four-point bending tests. The latter registered the rigidity, load capacity and deflection of the sandwich panels, as well as the main properties of their elements: for the core, shear strength and shear modulus, and for the skin layers, compressive strength and tensile strength. Cyclic tests evaluated the resistance of the material to loading-unloading cycles, while pull-off tests were used to verify the interface between the laminated composites and the AAC core. The results indicated a satisfactory performance of the sandwich panels, since the composite layers provided a strain/deflection hardening behavior to the material, increasing its flexural strength and toughness. The adhesion between the layers and the core proved to be effective, so that the comprised materials displayed adequate interaction between each other, as well as complementary properties. Among the objectives of this work is the development of a sustainable, lightweight, resistant and tough material, in a way that it represents a promising and low-cost alternative to Engineering applications.

Sandwich panels comprise a thick, light-weight plastic foam such as polyurethane, polystyrene or mineral wool sandwiched between two relatively thin steel faces. One or both steel faces may be flat, lightly profiled or fully profiled. Until recently sandwich panel construction in Australia has been limited to cold-storage buildings due to the lack of design methods and data. However, in recent times, its use has increased significantly due to their widespread structural applications in building systems. Structural sandwich panels generally used in Australia comprise of polystyrene foam core and thinner (0.42 mm) and high strength (minimum yield stress of 550 MPa and reduced ductility) steel faces bonded together using separate adhesives. Sandwich panels exhibit various types of buckling behaviour depending on the types of faces used. Three types of buckling modes can be observed which are local buckling of plate elements of fully profiled faces, flexural wrinkling of flat and lightly profiled faces and mixed mode buckling of lightly profiled faces due to the interaction of local buckling and flexural wrinkling. To study the structural performance and develop appropriate design rules for sandwich panels, all these buckling failure modes have to be investigated thoroughly. A well established analytical solution exists for the design of flat faced sandwich panels, however, the design solutions for local buckling of fully profiled sandwich panels and mixed mode buckling of lightly profiled sandwich panels are not adequate. Therefore an extensive research program was undertaken to investigate the local buckling behaviour of fully profiled sandwich panels and the mixed mode buckling behaviour of lightly profiled sandwich panels. The first phase of this research was based on a series of laboratory experiments and numerical analyses of 50 foam-supported steel plate elements to study the local buckling behaviour of fully profiled sandwich panels made of thin steel faces and polystyrene foam core covering a wide range of b/t ratios. The current European design standard recommends the use of a modified effective width approach to include the local buckling effects in design. However, the experimental and numerical results revealed that this design method can predict reasonable strength for sandwich panels with low b/t ratios (< 100), but it predicts unconservative strengths for panels with slender plates (high b/t ratios). The use of sandwich panels with high b/t ratios is very common in practical design due to the increasing use of thinner and high strength steel plates. Therefore an improved design rule was developed based on the numerical results that can be used for fully profiled sandwich panels with any practical b/t ratio up to 600. The new improved design rule was validated using six full-scale experiments of profiled sandwich panels and hence can be used to develop safe and economical design solutions. The second phase of this research was based on a series of laboratory experiments and numerical analyses on lightly profiled sandwich panels to study the mixed mode buckling behaviour due to the interaction of local buckling and flexural wrinkling. The current wrinkling formula, which is a simple modification of the methods utilized for flat panels, does not consider the possible interaction between these two buckling modes. As the rib depth and width of flat plates between the ribs increase, flat plate buckling can occur leading to the failure of the entire panel due to the interaction between local buckling and wrinkling modes. Experimental and numerical results from this research confirmed that the current wrinkling formula for lightly profiled sandwich panels based on the elastic half-space method is inadequate in its present form. Hence an improved equation was developed based on validated finite element analysis results to take into account the interaction of the two buckling modes. This new interactive buckling formula can be used to determine the true value of interactive buckling stress for safe and economical design of lightly profiled sandwich panels. This thesis presents the details of experimental investigations and finite element analyses conducted to study the local buckling behaviour of fully profiled sandwich panels and the mixed mode buckling behaviour of lightly profiled sandwich panels. It includes development and validation of suitable numerical and experimental models, and the results. Current design rules are reviewed and new improved design rules are developed based on the results from this research.