download: 832-6585-3-PB.pdf .Ultimate limit state curves of short reinforced concrete columns in fire situation are going to be presented in this paper. The authors created a code developed in Matlab. It makes a discretization of the cross sections of the columns and calculates the equilibrium integrals of them. The curves were plotted with the code considering the 500 °C isotherm method.Leia Mais
download: 836-5677-3-PB.pdf .Obtaining internal load capacity, in reinforced concrete sections, at ambient temperature, under biaxial bending, is one of the most common tasks done by structural engineers, but not so common when the member is in fire situation. The intention of this paper is to show that is possible to correlate the ultimate limit state (ULS), in fire situation, with ULS at ambient temperature, for square cross sections under fire from all faces. To reach the purpose and give support to the numerical analysis of this article, a computer program, in Delphi language, called COL FIRE, is being developed by the authors.Leia Mais
download: 866-5795-3-PBenglish.pdf .In many situations, the Brazilian Legislation does not require verification of roof structures in a fire, since its failure will not endanger the stability of the structure. In fire, the steel roof of an industrial building deforms by heating in geometry similar to a catenary, resulting in horizontal forces in the upper extremities of the columns. Thus, even roofs that do not constitute a frame with the columns may lead them to collapse, therefore, should be protected against fire. Due to the small dimensions of the structural elements of the roof, fire coating is uneconomical. So there is a problem in the design practice. This paper presents a procedure based on British literature, which considers the horizontal load on the columns. This horizontal load must be supported by the columns and the foundations. The aim of this paper is to detail this procedure, adapt it to Brazilian standards and apply it to a case study.Leia Mais
ABSTRACT The study of non-symmetrical composite columns is complex and European and North American standards only approach this issue superficially. In this text, a new proposal is presented for non-symmetrical composite column design subject to biaxial bending and axial compression, based on the compatibility of the deformation method, which considers the nonlinearity of the material with constitutive models according to Brazilian standards and geometric nonlinearity, as well as the equilibrium of the column in the displaced position. As a strategy for solving the general method, use is made of the "fiber element method", and for solving problems involving nonlinear equilibrium equations, the Newton-Raphson method.