NUMERICAL SOLUTION OF ROTATIONALLY PERIODIC STRUCTURES.

A method of solving properly discretized rotationally periodic structures composed of N substructures with M degrees-of-freedom (e. g. impeller wheels) is described. The method utilizes the structure of the total stiffness- mass etc. matrices (order N . M) of the complete solved object to transform them into block diagonal form of matrices or order M. Singificant reductions of both computer time and core storage requirements are achieved; a rough estimate of the savings is given for a static solution of rotationally periodic structures, subjected to general loads. The method is applicable to static, dynamic, stability, thermoelastic problems etc. It is illustrated by a static solution and calculation of natural frequencies and modes of simple plane frames.