Title:
Method of Segment Length for Instability Analysis of Reinforced Concrete Beam-Columns
Author(s):
Salah El-Din E. El-Metwally
Publication:
Structural Journal
Volume:
91
Issue:
6
Appears on pages(s):
666-677
Keywords:
beam-column frame; bending; columns (supports); compression; critical path method; deflection; deformation; critical path method; failure; moment-curvature relationship; nonlinear programming; reinforced concrete; Structural Research
DOI:
10.14359/1496
Date:
11/1/1994
Abstract:
A numerical method is presented for the instability analysis of reinforced concrete columns and beam-columns of known section dimensions from direct calculations. The solution assumes a deflection profile of the column or beam-column at the state of critical equilibrium. The value of the deflection at the position of maximum moment of the deformed beam-column is determined from the maximum moment capacity of the column or beam-column cross section, which corresponds to the point of section instability. From the assumed deflection profile, discrete values of curvature are calculated at stations located along the column span. The curvature is assumed to have a linear distribution between every two successive stations. From the discrete values of the curvature at the stations, the moment, and hence the deflection, values are determined at these stations. Then, the lengths of the segments between the stations are calculated to find the exact positions of the stations for which the obtained discrete values of curvature will be exact. Finally, the critical length for instability of the column or the beam-column can be determined and the deflection profile as well. Though it is numerical, the method of segment length for the instability analysis of columns or beam-columns does not require any iterations but leads to the (exact) solution with one step of calculation. The method is therefore computationally more efficient than the other available methods.