Abstract
Structural studies on the stair slad still remain backward compared with those on the beam, the column or the plain rectangular slab. Its practical design is beased on considerably bold assumptions whose inadequacy is often revealed in the resultant stractural cracking of the slab. In view of plate theory, probably onry an analysis for anisotropic stair slads with three edges fixed and one free has been presented, by Dr. Yokoo, all other related researches being made on the principles for the framed work in consideration of twisting effects. On the other hand some experimental reports have told that all the actions of the stair slab may not be presented in the frame theory. In this paper the method of difference is applied to orthogonally anisotropic elastic plates with slits or rectangular openings, supposed stair slabs. Then found distributions of bending moment or axial stresses either prove fairly good agreements with the result of the test loading of the corresponding stair slab models of steel, done by the authors. The data may lead to some design fundamentals of the stair slad.
