The analysis of vibration problems

In Part 1, the various ways in which vibration manifests itself, namely noise, vibration, stress and rotational oscillation, are considered. The available methods of measuring vibration are described and their relative merits and limitations discussed. Methods of calibrating measuring apparatus are given, with an indication of their limits. The suppression of vibration is considered from the points of view of what is desirable, how much can be obtained at the source and how much by resilient mountings, attention being given to the effect of ground and source impedance. Practical examples are given of the reductions in vibration which have been achieved in certain cases by improvements in the source and by resilient mountings. Part 2 concerns the determination of elastic design data on resilientmaterials and mountings for use as described in Part 1 for reducing vibration transmission. The limitations of a previous moving-iron-drive resonance-type method are discussed, and the advantages of a moving-coil-drive co-ordinate-potentiometer method pointed out. The apparatus is described in detail, and results of tests on typical materials and mountings are given and discussed.