桁板構造の最終強度に関する研究 (その1)

抄録

In this paper, the ultimate strength of girder plate structures in oil tankers or ore carriers has been investigated from view point of plastic failure of the structures under statical loading. Problems of local buckilng failure of members in the plate structures are not taken into consideration.
Based on the simplified lower bound theorem method of plasticity, theoretical analysis has been made on the plastic collapse of deep girders with round corners at both ends subjected to shear, axial force and bending, to determine the collapse load of the girders as well as the location of the plastic hinge at the round corners.
A method is presented of the plastic analysis on such girder structures, by introducing the concept of “plastic span-point” in a fictitious beam with uniform cross section, of which the collapse load is equivalent to that of the given girder.
Model tests have been also carried out to examine the collapse mode of the deep girders, measuring the development of yield zones in the web and the ultimate load carrying capacity of the girder specimens. Results of the tests have shown that the ultimate strength of the deep girders with round corners can be well predicted by the theoretical analysis.