TABLE OF CONTENTS In the preceding analysis of plastic beam-columns by curvature method, it was assumed that the beam-columns and loading conditions are symmetric. This condition of symmetry reduces significantly the number of possible combinations of elastic and plastic distributions of stress zone which may exist in a beam-column throughout the entire range of loading history (for example, six cases in Fig. 9.2). However, for the case of beam-columns with unsymmetric loading and boundary conditions, even if a direct solution to each individual case is possible, the labor involved for the solution of all cases which may exist in a beam-column limits its practical use. For the case of an eccentrically loaded column, for example, there are ten cases possible as shown in Fig. 10.3 which must be considered for a complete solution. In order to extend the curvature method to deal with the more general loading cases, new concept and methods are needed to furnish in a more direct manner the load-deformation relationship of such beam-columns.
The equivalent column concept is the concept which enables the Column Curvature Curve (CCC's) method to be developed to solve general plastic beam-column problems in a manner similar to the use of Column Deflection Curve method described previously in Chap. 8 (Chen and Atsuta, 1972). The application of the CCC method is simple and three types of CCC's cover all possible cases of elastic-plastic beam-columns. In the following, we will show that the general response of elastic-plastic beam-columns may be obtained...
