Approximations of Lateral Displacements of Reinforced Concrete Frames with Symmetric Haunched Beams in the Elastic Range of Response Using Commercial Software

摘要

Commercial software for structural analysis and design has significantly evolved in recent years. Nowadays, they are more user-friendly, in addition to providing engineers with more modeling options to solve complex problems and geometries. Tapered elements in general and haunched beams in particular were traditionally difficult to model in the past; therefore, most commercial software did not include them in their element libraries. Recently, leading commercial software worldwide for structural analysis such as ETABS or STAAD-Pro allow engineers to model haunched beams in the elastic range of response. However, the technical information provided within the software's manual does not always describe the details of the numerical modeling; i.e., whether it is based on rigorous traditional methods or is just an approximation based upon the calculus of variations. In this paper the approximations obtained with commercial software for a set of RC frames with symmetric haunehed beams under lateral loading in the elastic range of response are reported when compared with those obtained with a traditional beam theory in which shear deformations are included. It is shown that the modeling used in commercial software is in general reasonable; however, it leads to an underestimation of the lateral displacements. Depending on the software and the modeling option used, lateral displacements vary from 62 to almost 100% of those calculated using traditional beam theory.