Abstract
A dynamically loaded footing introduces elastic wave energy into the supporting soil. Part of this energy is returned to the footing to contribute toward its oscillatory motion and part is absorbed in the soil, there by producing a damping to the motion of the footing. It is important to maintain the distinction between these two types of energy losses. The former is called dissipation damping and the latter is called internal damping. The dissipation of elastic wave energy from a foundation can be studied by the use of the theory of elasticity and numerous solutions of the problem of a rigid circular footing vibrating at the surface of a semi-infinite elastic solid, have been made known by several authors. Several experimentally test results for a given masssoil system, proved that the internal damping far less contributes to the oscillatory motion of mass and the larger part of damping is occuppied by the dissipation type of damping. This report is devoted to the practical method of evaluating dissipation damping. This method of solution is a original attemption and though is far more brief in comparison with another methods treated on the wave energy diss'pation which have been developed by several authors, their solutions are shown in good agreement. This paper (part 1) includes as a practical example three problemes on the forced vibration of machinery foundation, those are simple motion (vertical, horizontal and rotational), combinative motion and two mass system.
