The Earthquake Engineering Online Archive

Refined modelling of reinforced concrete columns for seismic analysis

Kaba, Said A.; Mahin, Stephen A.

UCB/EERC-84/03, Earthquake Engineering Research Center, University of California, Berkeley, 1984-04, 104 pages (515/K15/1984)

The fiber representation of a section is extended to make possible the analysis of reinforced concrete or steel members independently or as part of two-dimensional frames. Slice stiffness is calculated from the fiber stiffness and the element stiffness is arrived at by integrating over the length of the element assuming linear flexibility between slices. Shape functions which relate slice deformations to element displacements are also calculated and updated. The fiber element is suitable for modeling beams and columns in a steel or reinforced concrete frame especially when the effects of axial loads on strength and stiffness are significant. Furthermore, the element can account for axial load-bending moment interaction and the pinching of hysteresis loops due to compressive loads acting on the element. The functioning of the element is tested separately and as part of a general dynamic two-dimensional frame analysis program (DRAIN-2D2). Analysis results are compared with experimental and other analytical results. The limitations and advantages of the element over other conventional discrete models are illustrated.

Available online: http://nisee.berkeley.edu/documents/EERC/EERC-84-03.pdf (4 MB)