EFFECT OF BEAM AXIAL DEFORMARION ON COLUMN SHEAR IN REINFORCED CONCRETE FRAMES

A computer program for nonlinear analyses of reinforced concrete frames was developed, in which beam axial deformations due to nonlinear cyclic loading were incorporated. The beam model was verified in detail through beam tests specially conducted with axial restraint force applied in proportion to the beam axial elongation. Nonlinear pushover analyses of reinforced concrete frame structures with different parameters, such as beam depth, number of spans, and number of stories, were carried out with and without considering beam axial deformations. Effects of beam elongation on column shear were investigated both analytically and theoretically. A simple and practical method for estimating magnification of the column shear due to the beam axial deformation was presented.