Isolation of a Rigid Body on Resilient Supports from a Vibration Environment

A rigid body on resilient supports, in general, has six degrees of freedom. Due to the complexity of the equations of motion and their solutions, simplifying assumptions are usually made regarding symmetry of the body, the orientation and/or dynamic properties of the supports, negligible product of inertia terms, etc. With the advent of the high-speed electronic digital computers, however, it is possible to set up a general program for predicting natural frequencies, and obtaining frequency response curves and static displacements due to inertia loading. The equations of motion of a rigid body supported by an arbitrary number of arbitrarily oriented and located resilient mounts with damping are developed with rigor and their steady-state solutions given for harmonic displacement excitation. A numerical example utilizing the preceding development is then presented.