This research deals with theoretical and experimental studies of timber composite beams reinforced by cold formed steel sheets, submitted to bending. A combination of different materials aims to the exploitation the advantages of each material, of manner to have a viable set, in constructive, structural and economic issues. For the accomplish of the research were tested three timber beams with dimensions 40mm x 120mm x 1050mm, six timber reinforced beams in the superior surface with metallic profile with dimensions 50mm x 25mm x 2mm and six timber beams reinforced in inferior surfaces and in the superior surface with the same metallic profile. The spacing between the connectors was of 100mm, 200mm and 300mm. With the objective of supplying the necessary dimensioning, theoretical formularizations for these studies were presented to the determination of internal moment and the estimated deflection. For this, the timber mechanical properties, the steel and the connectors were determined. With the results of the characterization tests of the materials, the simple and composite beams were tested in bending, for reading of stresses and maximum vertical displacements of the rupture on the inferior and superior extremities. Such values were performed by means of electric strain gauges and dial gauges. Also, were determined: the tensions in the elements of the beams and presented the chart of stresses x displacements. It was observed that, in relation to the timber simple beam, it had average increase at the ultimate load, for beams with reinforced parts in the compressed surface, of 20%, and 49%, when placed stiffeners in compressed and tensioned surfaces. In deflection values, it had the average reduction of 15%, when used stiffeners in the superior surface and of 49% in the parts with stiffeners, in the surfaces were performed to compression and tension. The biggest reduction in deflections happened in beams with lesser spacing between connectors, indicating that the influence of the interaction is bigger in relation to displacements, to bending moment. In stress distribution chart in the cross sections it was adopted, in all cases, the triangular form for the timber and for the profile, it was adopted a rectangular form. It was obtained results that differ from the experimental values in 17% for simple beams, in 16% for parts hardened with profile in superior surface and 21% for the parts hardened with profile, in the surfaces upper and lower, indicating that the proposal formularization can be applied with safety. In the calculation of deflections of geometric properties of composite section, in elastic regime, were performed with the homogenized section. It was presented the equation for the determination of correction factor of the estimated deflection for the studied cases.

parte dos requisitos para obtenção do Título de Doutor em Engenharia Civil. ORIENTADOR: Prof. Tit. Carlito Calil Jr São Carlos 1997 " Se o Senhor não edificar a casa, em vão trabalham os que a edificam; se o Senhor não guardar a cidade, em vão vigia a sentinela." SALMOS 127. Ao meu Senhor e eterno Salvador JESUS CRISTO, que me iluminou para realizar esse trabalho. À minha eterna companheira e esposa: ROSALINA pelo apoio integral. Aos meus filhos:KARINE E DANILO, que privei-me várias vezes de suas companhias para executar esse trabalho. Aos meus pais:DEODATO E ISABEL grandes professores da vida. Ao grande amigo e conselheiro PASTOR JARBAS A.VALENTIM, onde me inspirei em sua garra, ousadia e determinação para conseguir realizar seus ideais.

RESUMO: Este artigo apresenta o estudo experimental da capacidade resistente de vigas bi apoiadas em aço constituídas de perfis laminados de seção I do tipo W 250 x 22,3 ASTM A572 grau 50 laminados de abas paralelas com dois eixos de simetria, sendo dotadas de emendas com soldas de penetração total do tipo MIG (Metal Inert Gas). Foram ensaiadas sete vigas com comprimento de 3000 mm, sendo uma viga de referência. Nas seis vigas restantes foram confeccionadas emendas em diferentes posições variando a quantidade de emendas. Além disso, faz-se uma comparação com o comportamento de vigas com emendas parafusadas estudadas por Pereira (2014), no qual utilizou vigas com emendas nas mesmas disposições das utilizadas neste trabalho, mas com parafusos ASTM A325 e diâmetro de 19 mm. Todos os modelos foram submetidos a esforços de flexão simples até à ruptura, no qual foram medidos os deslocamentos verticais, deslocamentos relativos à torção e as deformações específicas do aço. As ligações das vigas resistiram aos ensaios de flexão simples, não sendo constatada nenhuma ruptura nas soldas e nem nos parafusos. A principal contribuição deste trabalho foi mostrar que as vigas com ligações soldadas e parafusadas, com as especificações descritas neste trabalho, podem ser utilizadas como elementos estruturais, pois resistiram bem aos esforços solicitados. ABSTRACT: This paper presents the experimental study of bearing capacity of bi supported by steel beams made of rolled section I of type W 250 x 22.3 ASTM A572 grade 50 profiles rolled parallel tabs with two axes of symmetry, being endowed with amendments with full penetration welds of type MIG (Metal Inert Gas). Seven beams were tested with a length of 3000 mm, with a reference beam. In the remaining six beams amendments were made in different positions varying the amount of amendments. Furthermore, it is a comparison with the behavior of beams with bolt seams studied by Pereira (2014), in which beams used with the same provisions of seams used in this work, but with ASTM A325 and screw diameter of 19 mm. All models were subjected to simple bending stress at break, in which the vertical displacements were measured relative displacements and specific torsional deformations steel. The links of beams resisted the simple bending tests, not being detected no break in welds and even the screws. The main contribution of this work was to show that the beams with welded and bolted connections with the specifications described in this paper can be used as structural elements, as well resisted the efforts required.

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