Abstract
This paper contains the results of a study made on a turbine foundation for the purpose of elucidating conditions which favor the building up of excessive vibrations when the unit is in operation. The structure studied was a steel framework supporting a concrete table with a turbogenerator erected on it. The experimental part consists of (a) dynamical loading of the structure and (b) determination of its elastic constants. The theoretical treatment of the problem consists of the determination of the frequencies and the modes of the natural vibrations by analytical methods. A comparison of the theoretical results obtained with the experimental findings is made. The results of the study indicate that vibrations of a turbogenerator on its foundation, for units of conventional design, can be treated as vibratory motion of a deformable body supported by a system of massless springs. Some rules to be followed in designing and means of changing a critical frequency in a desired sense also are included.
The present investigation was undertaken in an effort to eliminate the uncertainty which exists in the design of the foundations for turbogenerators, particularly where a steel substructure is used.
