MEASUREMENT FOR 4-POLE PARAMETERS OF VIBR ATION REDUCING MECHANICAL CONSTRUCTIONS

With regard to the measurement of the four-pole parameters of vibratio n-reducing and structure-borne noise damping construction elements thr ee methods are mentioned, the short circuit/no-load method, the revers e method and the two-impedance method. For measurement it is necessary to have an excitation chain, a two-channel FFT analyser and a compute r for evaluation purposes with software for processing complex quantit ies. Measurement is also possible in structures without removing the d amping elements to be measured, but the source and terminating impedan ces have to be known. A table facilitates selection of the most practi cal measuring method.