C V R Murty

A simple hand calculation based method is presented to develop axial flexure design P-M interaction curves of rectangular reinforced concrete sections. The proposed method uses basic principles of mechanics satisfying compatibility of strains, equilibrium of forces and constitutive relations of constituent materials. Simple step-wise calculation is enough to develop the interaction curve; it does not require any iterations. Accuracy of the method is demonstrated by comparing the results of two RC sections with the interaction curves of the sections obtained using SP:16. Step-wise calculations are presented of the two RC sections to illustrate the use of this method for generating design P-M interaction curves.

A simple approach is presented to derive limiting strain-based bilinear overstrength moment-curvature response curves of reinforced concrete sections. These curves are obtained by simple hand calculations proposed in the paper. Implications of use of these idealized curves are examined on estimating seismic behaviour of RC frame buildings by nonlinear static pushover analyses. The use of idealized moment-curvature curves and its properties, as proposed, offers a consistent and non- empirical approach compatible with actual section properties.