A simple method for predicting the ultimate strength and mode of failure of reinforced concrete beams subjected to pure torsion is presented This method is an extension of a recently developed met

Torsional strength of reinforced concrete beams

Fracture behavior of RC members subjected to bending shear and torsion using acoustic emission method

Current specifications set up by American Association of State Highway and Transportation Officials Load and Resistance Factor Design (AASHTO-LRFD) guidelines allow two different procedures for the design of concrete beams subjected to torsion and shear. These are based on a simplification of the equations of the modified compression field theory. This article reports on a study that evaluated this procedure. The author compares his results with available test data on beams subjected to various load combinations such as pure torsion, combined torsion and bending, combined torsion, bending and shear, and combined torsion and axial compression. Typical interaction diagrams between torsion, shear and bending, and axial load are also presented. The results show that the method generally provides conservative results and accurate representations of the interaction between torsion and the other stress resultants; it also calculated the shape of the interaction diagrams and surfaces with reasonable accuracy. The author cautions that the standard equation used to calculate the torsional shearing stress is not accurate.

Evaluation of AASHTO-LRFD general procedure for torsion and combined loading

Full three-dimensional nonlinear finite element analysis based on the path-dependent non-orthogonal multi-directional crack model is applied to RC columns subjected to combined cyclic flexure/shear and torsion. This loading causes non-orthogonal crack-to-crack mechanistic interactions accompanying opening/closure and shear slip along crack planes. The analytical results show that the proposed methodology is able to simulate the highly nonlinear behavior of RC columns under cyclic loading, including not only load-carrying capacity but also complex restoring force characteristics and post-peak softening after peak strength. Sensitivity analysis is also carried out to examine the effectiveness of the transverse reinforcement, which simultaneously resists both transverse shear and torque moment. The current design procedure for determining the necessary and sufficient amount of web reinforcement is reviewed and the necessity of performance assessment is raised.

Three-Dimensional Cyclic Behavior Simulation of RC Columns under Combined Flexural Moment and Torsion Coupled with Axial and Shear Forces

Sonderaspekte zur Schubbemessung nach DIN 1045‐1 und EC 2

In an effort to predict the load-deformation response of reinforced concrete elements subjected to pure torsion, an analytical model is proposed in this study. In this model, compressive stress-strain curve and tensile stress-strain curve of concrete struts between diagonal cracks are considered in equilibrium. Experiments were then conducted to verify the validity of this model. The experimental and analytical values have been found to be in good agreement and the proposed model is thus capable of predicting not only the strength but also the angle of twist, the steel strains and the concrete strains throughout the loading history. The concrete cover and the reinforcement ratio are also found to have significant effect on the change of shear flow.

Seung Han Lee

Papers

A study on mechanism of torsional resistance of reinforced concrete members