Verificação de pilares no ELU submetidos à flexão composta oblíqua

Abstract

In most cases, columns are subjected to biaxial bending with axial load (oblique combined bending). Situations involving uniaxial combined bending are relatively rare. Once the column dimensions are defined, and considering the case of oblique combined bending, for each distribution of longitudinal reinforcement and a given axial load (Nd), the pair of maximum resistant moments in uniaxial combined bending around each axis, MRdx and MRdy, can be determined. These values serve as the basis for constructing the resistant ellipse in oblique combined bending. The verification of a column at the Ultimate Limit State under oblique combined bending is performed by plotting the ordered pair (Mdx, Mdy) on the graph corresponding to the column’s resistant ellipse. For the column to withstand the applied loads (Mdx, Mdy), this point must lie inside or on the boundary of the ellipse. This study developed a calculation memorandum and implemented, in a spreadsheet, the steps required to generate interaction diagrams for uniaxial combined bending for a given cross-section and longitudinal reinforcement distribution. With these diagrams plotted and the axial load (Nd) defined, the maximum resistant moments around each axis (x and y) are obtained. Using these maximum resistant moments, the resistant ellipse is drawn, which serves as the reference to classify whether the cross-section can resist the considered loading. The spreadsheet is intended to be used as a tool for self-learning on the subject.