An Object-Oriented Programming Approach for the Analysis of Spatial Reinforced Concrete Frames

New construction methods and progress in concrete technology render possible bolder and more slender structures. While the non-linear computation of plane frame structures usually shows good accordance with experiments, many analysis programs still fail to adequately model reinforced concrete frames under spatial loading. The material non-linearity usually is captured at cross-sectional level. Most programs consider the effects of interacting normal and bending forces on the cross-sectional stiffness. However, for instance the interaction between torsion and bending is mostly neglected, or considered by simplified methods. A hybrid cross section model developed at the institute of the authors combines a uniaxial model with a wall model and thereby allows for interactions between all six internal forces of a spatial frame element. An object-oriented approach is chosen for the implementation into a software module. Presently, the module is integrated into a finite-element framework in order to assess its influences on the computation of spatial frame structures.