Behavior of short reinforced concrete column with non-orthogonal biaxial moment and axial load

Abstract

urrently, the building structures are constructed in different shapes to keep the functionality of the building. Due to this, the reinforced concrete column may be subjected to two beams that run in non-orthogonal ways (other than 90 degrees). However, there hasn't been enough research done on the behavior of this type of column. The purpose of this study is to investigate the behavior of a short non-orthogonal biaxially loaded reinforced concrete column. The FEA software, which is Abaqus 6.14, was used for this study. Before modelling of the specimen, the experimental study, which was done by Wang G.G. and Thomas Hsu C.T., was used as a benchmark experiment and used for validation. The FEA results agreed with the experimental results up to 84% . The concrete and steel properties, which were used for software input, were prepared and modelling of the specimen was done. The Abaqus standard was used for modelling of 270 column specimens, and Concrete damage plasticity for concrete and plastic, for steel models, was used in the material property definition. Both tie and embedded region constraints were used in the interaction module. Eccentricity, concrete grade, angle between the axis of the moment, shape of the column, force, and displacement were variables considered in this study. In which force and displacement were considered, as dependent variables and the remaining were independent. As eccentricity increases from 10 to 50mm along both directions for a short non-orthogonal biaxially loaded reinforced concrete column, the load-carrying capacity of the column reduces by an average value of 8.9% and the deflection increases by an average value of 12%. When the angle between the axis of moment increases from 15o to 90o , the axial load-carrying capacity of column reduces by an average value of 1.014% and its deflection increases by an average value of 0.7342%. As the concrete grade increases from fck 20 to 30Mpa, the axial load-carrying capacity of non-orthogonal RC columns, within interval, by an average value of 11.31% and the deflection reduces by an average value of 2.27%. The axial load-carrying capacity of the non-orthogonal square RC column is higher than the rectangular by 1.44%, but the deflection is smaller by 0.516%. For non-orthogonal biaxial moment, the circular column axial load-carrying capacity is higher than square and rectangular by 0.192% and 1.66%, respectively. Therefore, a circular column is preferable to other shapes of columns