Análise e comportamento de vigas de aço e vigas mistas com aberturas na alma

Abstract

This work consists of a study about the behavior of steel and compositebeams with web openings. A design procedure for I beams with one or more web openings is developed, using the Limit State Method. The various ultimate limit states related to the acting of the bending moment and shear are described and their corresponding design strengths are evaluated. Using this procedure it is possible to identify the situations in which the openings should be reinforced and to design suchreinforcements. The openings can be rectangular or circular, concentric or excentric. It is also included in this work a critical evaluation of the K annexe of the Brazilian Specification for project and execution of building steel structures, NBR 8800, published in 1986, that deals specifically with openings in beam webs. A proposal to make the text of the annexe more extensive, specially in relation to the openings dimensions, shape and positioning is presented. Design procedures are presented, based on the stiffness method to determinate deflections in composite and noncomposite beams, using a specific stiffness matrix to the opening element. A computer program has been developed using the theory presented in the work, to design composite and noncomposite beams with web openings and to evaluate their deflections.