Dieterman H.A. and Metrikine
A.V. 
Eigenfrequencies and simplified models of semiinfinite cascades with variable boundary mass 

Summary. The eigenfrequencies of a semiinfinite cascade of massspring systems with variable boundary mass are studied. The investigation shows that real eigenfrequencies only occur for a boundary mass equal to or smaller than half the mass of the bodies in the cascade. For values of the boundary mass between a half mass and a full mass the cascade shows to have no eigenfrequencies. For a boundary mass larger than the internal masses only imaginary eigenfrequencies are present. Frequencyresponse functions for the different cases are derived. Some simplified models for the semiinfinite system are given and a comparison is made with the dynamic behaviour of continuous systems. 