Análisis seccional de dos columnas compuestas de acero ASTM A572 grado 50, rellenas con hormigón de resistencia 𝑓′𝑐 =280 𝑘𝑔𝑓/𝑐𝑚2, en el rango no lineal, realizado por el método de fibras programado en OpenSees, con comprobación en Excel y SAP2000

Abstract

The analysis of the non-linear behavior of steel and concrete can be carried out by studying the contribution of the axial force and bending moment of each of the parts that are formed in the stress-strain curve, based on the codes of ACI and ANSI/AISC design. By taking into account the participation of both materials in the inelastic range, the total bending and axial force resultant in the cross section is obtained, which allows a more realistic moment-curvature diagram to be elaborated. The main objective of this research is to determine the ultimate capacities of two composite columns (SRC) of circular and square section. To do this, a routine based entirely on the Popovic and Kent-Park fiber method has been developed at OpenSees. Both columns were subjected to three different axial loads: 0 kN for the case of pure bending, 500 kN in tension, and -1000 kN in compression. The results show that the moment capacity of the section increases as the compressive axial load increases, until reaching the balanced condition of the M-N interaction curve.