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.
