Este trabalho tem por finalidade, o estudo do comportamento do adesivo poliuretano à base de mamona para o emprego em madeira laminada colada (MLC). A eficiência do adesivo foi avaliada por meio da resistência dos seguintes ensaios mecânicos: cisalhamento, tração normal e tração paralela às fibras. Os ensaios seguiram as recomendações da norma brasileira NBR 7190/97 \"Projeto de estruturas de madeiras\" e por meio de seus resultados foram determinados os parâmetros de colagem como: viscosidade (V), tempo de pressão de colagem (Tp), pressão de colagem (P) e tempo de cura (Tc) e avaliadas as influências dessas variáveis e de suas interações sobre as resistências. Duas espécies de madeira foram empregadas: o Pinus caribea hondurensis e o Eucaliptus grandis, geralmente empregadas em reflorestamento nas regiões Sul e Sudeste do Brasil, onde estão localizadas as indústrias de MLC. O adesivo estudado é do tipo bicomponente, o poliol B1640 e o prepolímero A249, oriundo de recurso natural e renovável, de cura a frio, não agressivo ao ser humano e nem ao meio ambiente e é uma tecnologia nacional. Os resultados mostraram que o adesivo à base de mamona é um boa alternativa para a utilização da madeira laminada colada em estruturas com espécies de reflorestamento. / The aim of this work is the study of the polyurethane adhesive based on castor oil in glued laminated timber structures (GLULAM). The efficiency of the adhesive was evaluated using the following mechanical tests: shear, perpendicular and parallel tension to the grain strengths. The Brazilian Code NBR 7190/97 \'\'Design of the timber structures\" was used to the tests and based on these results were determined the gluing parameters as: viscosity (V), gluing pressure (P), time of pressure (Tp) and the curing time (Tc) and evaluated the influence of these variables and interactions on the mechanical strengths. Two wood species Pinus caribea hondurensis and Eucaliptus grandis were chosen because they are used as reforestation in South and Southeast areas in Brazil where are located the glulam industries. The adhesive studied is of the two components, that is, the poliol B1640 and the prepolymer A249 and is made of a natural and renewable resource, cure in the environment conditions, not aggressive to man and the environment, and a national technology. The results showed a good performance of this adhesive, a good technical alternative for the technology utilization of GLULAM in timber structures with reforestation species.

The gluing of unseasoned wood, called green gluing, is a relatively new sawmill process, implying a radically changed order of material flow in the production of value-added wood-based products. It facilitates the enhancement of raw material recovery and value yield by integrating defect elimination and gluing already before kiln drying. The present study evaluates green glued adhesive bonds in flatwise glued beams and finger joints. The main part of this work deals with green gluing using a moisture curing polyurethane adhesive (PUR). Standardised test methods and specially designed, small scale, specimens were used for the determination of the strength, fracture energy and the ductility of both dry- and green glued bonds in tension and in shear. Using the small scale specimens it was possible to capture the complete stress versus deformation curves, including also their unloading part. An optical system for deformation measurement was used for the analysis of bond behaviour. The influence of moisture content during curing and temperature after curing on the adhesive chemical composition and on the mechanical properties was investigated. Furthermore, the moisture transport through the adhesive bond during curing was tested. Finally, microscopy studies were performed for analysis of bond morphology and fracture. The results show that two significant factors influence the shear strength of green glued bonds: wood density and adhesive spread rate. Bonds which fulfil the requirements according to EN 386 could be obtained within a wide range of process parameters. The small specimen tests showed that green glued PUR bonds can reach the same strength and fracture energy, both in shear and in tension, as dry glued bonds with the same adhesive amount. The local material properties of the bonds could be determined, thanks to the failure in the tests taking place within the adhesive bond itself and not in the wood. Following process factors were shown to cause lower bond strength: a) a low adhesive spread rate, b) high pressure and c) short pressing time in combination with low wood density and high moisture content. Moreover, the heat treatment of the cured PUR adhesive during drying influenced the chemical composition of the adhesive, providing for higher strength, stiffness and Tg of the adhesive, caused by an increased amount of highly ordered bidentate urea.

The aim of this thesis was to evaluate the use of dynamic excitation as a method for stiffness and strength grading of wet side boards of narrow dimensions. The need for such an investigation has previously been identified in an ongoing research project in which the possibility to use side boards as lamellae in wet glued glulam beams is investigated.      The assessment of the dynamic excitation method was carried out by means of experimental work and measurements.. The approach was quantitative in the sense that the data was collected through experiments performed on a rather large population and that the results were analyzed using statistical methods.      To investigate the effect of moisture content on stiffness of narrow dimension, side boards, the stiffness was measured in three states: - in wet state, before splitting the boards, - in wet state, after splitting the boards, and - in dry state (splitted boards).      The conclusion, after calculations and analysis of all the results, was that the natural frequency and stiffness of wet boards could, with a high degree of reliability, be predicted by use of the dynamic excitation method. There was a strong correlation in stiffness between wet state split boards and dry state split boards, with a coefficient of determination of 0.93.

<p> The aim of this thesis was to evaluate the use of dynamic excitation as a method for stiffness and strength grading of wet side boards of narrow dimensions. The need for such an investigation has previously been identified in an ongoing research project in which the possibility to use side boards as lamellae in wet glued glulam beams is investigated.</p><p>     The assessment of the dynamic excitation method was carried out by means of experimental work and measurements.. The approach was quantitative in the sense that the data was collected through experiments performed on a rather large population and that the results were analyzed using statistical methods.</p><p>     To investigate the effect of moisture content on stiffness of narrow dimension, side boards, the stiffness was measured in three states:</p><ul><li>- in wet state, before splitting the boards,</li><li>- in wet state, after splitting the boards, and </li><li>- in dry state (splitted boards).</li></ul><p>     The conclusion, after calculations and analysis of all the results, was that the natural frequency and stiffness of wet boards could, with a high degree of reliability, be predicted by use of the dynamic excitation method. There was a strong correlation in stiffness between wet state split boards and dry state split boards, with a coefficient of determination of 0.93.</p>

No presente trabalho avaliou-se a resistência mecânica do bambu nos estágios pré e pós processamento mecânico para servir de referências básicas do estudo das propriedades mecânicas de vigas laminadas coladas simples, de seção composta e de seção composta na forma de I, industrializadas em laboratório. Iniciou-se com a caracterização do material bruto na forma de ripa que representa toda a parede do colmo, passando-se pelo material processado na forma de lâmina que representam a parte industrialmente útil da parede do colmo e culminando na manufatura e qualificação das vigas laminadas coladas. Na produção dos corpos de prova do material bruto manteve-se a espessura original da ripa, exceto para alguns produzidos para se avaliar a resistência ao cisalhamento radial das camadas interna e externa da parede do colmo. As ripas foram usinadas em diversas máquinas para serem transformadas em lâminas que são as unidades de composição das seções compostas pela técnica de aglutinação e adesão a frio. Foi estudada também a influência do nó na resistência ao cisalhamento radial e tangencial tanto do material sólido quanto do plano de cola e nas propriedades da flexão. A geometria e as dimensões dos corpos de prova de cisalhamento foram adaptadas da norma ASTM D 905 e os de flexão da norma NBR 7190. As resistências ao cisalhamento no plano de cola e as propriedade da flexão foram determinadas segundo três combinações de faces de contato no processo de colagem com o adesivo à base de resorcinolformaldeído (RF). Estudou-se também a pressão adequada para colagem dos corpos de prova e eleita a mais adequada à colagem de vigas laminadas coladas. Os corpos de prova intactos e rompidos nos ensaios foram observados em microscópio eletrônico de varredura, em microscópio óptico, em microscópio óptico de fluorescência e microscópio estereoscópico. Observou-se ampla variabilidade das propriedades mecânicas tanto do material sólido quanto do material composto, mas em qualquer dos casos de resistência houve ampla variabilidade dos dados e, no geral o material sem nó foi mais resistente do que o com nó. As rupturas ocorreram na maioria das vezes no tecido parenquimático desviando-se dos feixes de fibras e tendendo a seguir a grã do material observando que o plano de ruptura só coincide com o plano planejado para a ruptura quando o corpo de prova é feito com a consideração precisa da orientação da grã. Os corpos de prova montados com a cola à base de PVA e com lâminas nodais responderam de forma satisfatória à colagem a baixa pressão, enquanto que os fabricados com lâminas internodais apresentaram melhor desempenho a alta pressão. Para os corpos de prova manufaturados com o adesivo à base de RF, a melhor combinação de colagem se deu no contato entre faces externas de lâminas. Foi possível observar a penetração do adesivo nos elementos anatômicos das lâminas com o uso da microscopia óptica e de fluorescência. As vigas laminadas coladas de seção transversal composta foram ensaiadas à flexão, mas não romperam por tensão normal, pois apresentaram instabilidade lateral durante o carregamento à flexão. As vigas também apresentaram baixo módulo de elasticidade porque o esmagamento da mesa inferior, nos apoios, foi cofundida e somada pelo sistema de medida, ao valor da flecha. Numa análise geral, a qualidade mecânica da Viga \"I\" pode ser considerada muito boa dentro do correto cálculo do momento de inércia se seções transversais compostas. As camadas perpendiculares ao eixo da via, tanto na alma quanto na mesa, foram tão eficientes na absorção do esforço cortante que não houve nenhuma limitação de capacidade de carga pela ligação alma-mesa mesmo com a viga trabalhando numa faixa de alta influência de tensões cisalhantes. / In this study it was evaluated the bamboo strength in the stages before and after mechanical processing in order to obtain basic references to study the mechanical properties of simple glued laminated beams of composite section and composed section as I joist, manufactured in laboratory scale. It started with the characterization of raw material as strip representing the crude bamboo culm wall, moved to the processed material as in the shape of laminas which were representing the majority of bamboo culm wall industrially useful and culminating to the manufacture and qualification of glued laminated beams. In the production of specimens of raw material it was maintained the original thickness for the strip except for a few ones which were produced to evaluate the radial shear strength in the inner and outer layers of the culm wall. The strips were machined on some machines to be turned into laminas that were the units for assembling composite sections by agglutination and adhesion under pressure in environmental conditions. It was also studied the node influence in the radial and tangential shear strength in both solid material and in the adhesive plan and in properties got from the bending tests. The geometry and dimensions of the shear specimens were adapted from ASTM D 905 and the bending from NBR 7190. Shear strength in the adhesive plane and bending property were determined following three combinations of contact faces on the gluing process using resorcinol-formaldehyde based adhesive. It was studied also the proper pressure for gluing the specimens and elect the most suitable for glued laminated beams. The intact specimens and failed on mechanical tests were observed under a Scanning Electron Microscope, Optical Microscope, Optical fluorescence microscope and stereomicroscope. It was observed huge variation of mechanical properties in both solid and composite materials, but in all cases there was considerable variability of strength data and in general the material without node was more resistant than with node. The ruptures mechanisms occurred most often in the parenchyma tissue by passing the fiber bundles and tend to follow the grain of the material by observing the rupture plane that only coincides with the plan designed to rupture when the specimen is done with precise consideration of grain orientation. The specimens manufactured with PVA adhesive and components with nodes responded satisfactorily to the low pressure bonding, while the specimens produced with internodes components performed better at high pressure. For specimens manufactured with resorcinol-formaldehyde adhesive the best gluing combination was given by the contact of outer laminas surfaces to each other. It was possible to observe the anchorage of the adhesive into the anatomical tissues by using optical microscopy and fluorescence optical microscopy. Glued laminated beams with composite cross section were tested in bending, but not failed by normal stresses, once there occurred only lateral instability during loading time. The I beams also showed low modulus of elasticity because the crush in the inferior flange was added by the measurement system to the bending deflection. In general the mechanical quality of the \"I\" joist can be considered very high with correct calculation of the moment of inertia of composite cross sections. The layers perpendicular to the beam axis both in web and in the flanges, were so efficient in absorbing the shear that there was no limitation of carrying load web-frange connection even with the beam working in a critical influence of high shear stresses.

Este trabalho tem por finalidade, o estudo do comportamento do adesivo poliuretano à base de mamona para o emprego em madeira laminada colada (MLC). A eficiência do adesivo foi avaliada por meio da resistência dos seguintes ensaios mecânicos: cisalhamento, tração normal e tração paralela às fibras. Os ensaios seguiram as recomendações da norma brasileira NBR 7190/97 \"Projeto de estruturas de madeiras\" e por meio de seus resultados foram determinados os parâmetros de colagem como: viscosidade (V), tempo de pressão de colagem (Tp), pressão de colagem (P) e tempo de cura (Tc) e avaliadas as influências dessas variáveis e de suas interações sobre as resistências. Duas espécies de madeira foram empregadas: o Pinus caribea hondurensis e o Eucaliptus grandis, geralmente empregadas em reflorestamento nas regiões Sul e Sudeste do Brasil, onde estão localizadas as indústrias de MLC. O adesivo estudado é do tipo bicomponente, o poliol B1640 e o prepolímero A249, oriundo de recurso natural e renovável, de cura a frio, não agressivo ao ser humano e nem ao meio ambiente e é uma tecnologia nacional. Os resultados mostraram que o adesivo à base de mamona é um boa alternativa para a utilização da madeira laminada colada em estruturas com espécies de reflorestamento. / The aim of this work is the study of the polyurethane adhesive based on castor oil in glued laminated timber structures (GLULAM). The efficiency of the adhesive was evaluated using the following mechanical tests: shear, perpendicular and parallel tension to the grain strengths. The Brazilian Code NBR 7190/97 \'\'Design of the timber structures\" was used to the tests and based on these results were determined the gluing parameters as: viscosity (V), gluing pressure (P), time of pressure (Tp) and the curing time (Tc) and evaluated the influence of these variables and interactions on the mechanical strengths. Two wood species Pinus caribea hondurensis and Eucaliptus grandis were chosen because they are used as reforestation in South and Southeast areas in Brazil where are located the glulam industries. The adhesive studied is of the two components, that is, the poliol B1640 and the prepolymer A249 and is made of a natural and renewable resource, cure in the environment conditions, not aggressive to man and the environment, and a national technology. The results showed a good performance of this adhesive, a good technical alternative for the technology utilization of GLULAM in timber structures with reforestation species.

This diploma thesis deals with bonded hybrid joints which are used for connecting parts of modern coachwork. Firstly, the thesis describes in general the process of production of the whole coachwork, from cutting of the blanks to the surface treatment including the analysis of the used materials. Subsequently, the problem of joining body parts through adhesives, but also by welding, soldering or other methods is discussed. Another part of this thesis is dedicated to an experiment in which the qualities of bonded hybrid joints were determined. Different ways of realizing the joint have been made which differed in the size of the glued surface, in the welding methods and in the process of their creation. The produced joints were tested for their strength and quality.

The diploma thesis deals with the design of a general concept workplace for gluing magnets to the DC stators. The thesis is focused on the selection of industrial robots and their location, the design and the construction of end effectors for manipulation with segments and stators and the proposal of solution for engineering units on a workplace. Among the construction units belong: revolving tables with gripping systems, rotary tables on pallets and construction manipulators. At the end of the thesis the concept of the solution for workplace safety is created according to current legislation and safety standards.

Master thesis is focused on proposal of improved manufacturing process of assembly named "sandwich" produced in Iveco bus company. There is solved new fixation of assembly bench, replacement of currently used glues and material of ledge as well. In the first part there is company introduction Iveco Bus. Second part consist of construction analysis and description of present manufacturing process. Further there is introduction, solving out of thesis topics and proposal of new manufacturing process is written. At the end of thesis are attached comparison between present and proposed manufacturing process.

<p>QCR 20161026</p>