Deformation of an Eccentrically Compressed and Torsionally Loaded Reinforced Concrete Element

Statement of the problem. Currently, there are no analytical calculation models that adequately reflect the stress-strain behavior of reinforced concrete elements under eccentric compression combined with torsion. Numerical solutions to this problem are approximate in nature. Therefore, the aim of this study was to develop a computational model and an analytical method for predicting the deformation of such elements under large eccentricities at post-cracking stages. Results. A deformation model was developed to determine the stress-strain state in the spatial cross-section of an eccentrically compressed and torsionally loaded reinforced concrete element. Analytical deformation relations were derived to calculate strains in the concrete compression zone, longitudinal and transverse reinforcement bars, as well as curvatures and rotation angles of the spatial cross-section. Conclusions. The obtained analytical relationships allow for the determination of interrelated design parameters in a cracked reinforced concrete element: stresses in the concrete compression zone, the height of the compressed concrete, and forces in longitudinal and transverse reinforcement bars under the combined action of an eccentrically applied axial force and a torsional moment. The proposed computational model can be used in the design of a wide range of reinforced concrete structures under the considered stress state to assess serviceability and ultimate limit states.