Abstract
It is widely known that the results of plastic buckling tests of plates are well correlated by a simple total or deformation theory, but not by an incremental or flow theory which is theoretically, experimentally recognized to be valid. Onat and Drucker, however, demonstrated in a simple example that extremely small, and therefore unavoidable imperfections of shape do account for the paradox. In previous authors' papers, there are discussed uniqueness and stability in elastic-plstic plates; in the case of the long rectangular plate hinged along one edge and free on the other under uniform compressive stress at the ends, it was examined how much the imperfection influence the stability limit. At the standpoint of Plastic Design, however, the initiation of excessive deformation or deflection of plates has to be offered attention rather than the stability limit. Therefore we have to discuss load-deflection behaviors of plates at the presence of initial deflections. The load-deflction behavior can be obtained by solving a rate problem which takes account of the geometry changes in step by step procedure. In this paper, the whole curves of load versus deflection of a solid plate under the above mentioned boundary and loading conditions are shown, and then a large amount of discrepancy between the theoretical plastic buckling load and the load corresponding to the initiation of excessive deflection is revealed.
