The Analysis of the Deformations θ and R of Rigid Frames， in which the Joints move laterally，based on the Foundation of the Principles of Cramped-Moment Method.

The end moments of the members of rigid frames, in which the joints move laterally, are generally calculated by the Cramped Moment-Type Method. The author considers the basis of the cramped-moment method as follows : First， restraining the joint ro-tation the previous lateral displacements ΔRare calculated ; then the corresponding rot rotations Δθ are able to be expresseo by the pisplacements of adjacent stories. Finally， the true rotations and displacements are obtained as summations of Δθ and ΔR respectively. Thus θ and R are alternately using， deformations of joints or stories obtain in any degree of accuracy desired. In the same way the end moments of members are determined by a common metho