Simultaneous propagation of vibrations and noise has an important role in the task of minimizing vibroacoustic hazards on the station of operator of the construction machinery. In many cases vibrations transferred by the construction are processed to noise in different points of the machine. As a result, they may increase the level of noise at the workplace. The paper presents the proposition of a simple estimation of noise and vibration propagation paths of the machine. On the basis of the analysis of hydraulic excavator an effectiveness of a proposed procedure was shown. This procedure helps to minimize the transfer of vibrations of power unit in selected frequency ranges which led to the change of overall noise level in operator’s cab about 5 dB.
The article is a continuation of the authors’ elaboration (Dąbrowski, Dziurdź, 2016). The aim of this continuation is to prove that a proposed way of modelling and using the coherent analysis to filter nonlinear disturbances is a useful technique in vibroacoustic diagnostics. The thesis was proved by solving the task of diagnosing the damage of the gear of the car gearbox on the basis of the measurement of mechanical vibrations and the noise in the engine chamber.
In spite of the fact that standardizing operations and increased awareness of hazards led to a significant improvement of vibroacoustic climate of operator’s stands of new machines, their long-term operation - often under difficult conditions - leads to a fast degradation of acoustic qualities of machines. Temporary operations performed during surveys and periodical overhauls are rarely effective, due to the lack of any guidelines. In this situation the authors propose the algorithm for selection of eventual screens or sound absorbing and sound insulating partitions, utilizing the measuring procedure aimed at identification, at the operator’s stand, of main noise components originated from various sources. On the basis of this procedure, the vibroacoustic energy propagation paths in the machine was estimated.