Analysis of the Impact of Different Types of Vibration Isolation on the Dynamic Loading of Machines and the Surrounding Environment

Abstract

The resulting dynamic loading on machines, the environment and humans generated by vibration and noise is dependent on the vibro-insulating components and the quality of resilient materials used in the mounting of these components. Well-designed vibration isolation of vibrating sources can effectively reduce the transmission of vibro-acoustic energy into supporting and surrounding structures. Based on frequency spectrum, the vibro-isolation efficiency of various vibro-insulating components and their resilient materials is analysed. The solution of this problem is based on theoretical knowledge and methodology of the transmission of vibration-sound waves and measurement of the machines involved. Measurements of vibration at the sources and along the path of transmission, as well as sound measurements, were performed for different vibro-isolators to compare real results with theory. Measured components include; isolation of a recirculation fan in a heating plant, air-conditioning unit, and combustion engine of a passenger vehicle. For the detection of the vibro-acoustic energy the vibration and sound were measured and FFT analysis was applied. Finally, this paper suggests measures which can be taken to reduce undesirable vibro-acoustic energy on machines, the environment and bystanders.

Using of Recycled Materials to Protect the Working and Natural Environment by Reducing Noise and Vibration

“…The use of these materials as vibro-isolators in the field of seismic waves (very low frequencies) is not effective. This fact is also confirmed by the measurements made so far [15,16,17]. It is at very low frequencies that the combination of springs and viscoelastic materials is effective.…”

“…A fixed contact is assumed at each connection between the vibration source and vibro-isolator and between the vibro-isolator and the receiver. This is done by measuring the transmission function of the mass-loaded material at all the required frequencies [17]. The methodology uses a vibration excitation system, above which the viscoelastic material is placed with the loading mass m (vehicle body, mounting support, building and technological structure, i.e.…”

“…The matrix elements are basically special forms of frequency-response functions; they describe linear properties of mechanical and acoustical systems. On the basis of the knowledge of the individual subsystem properties, corresponding properties of assemblies of subsystems can be calculated [15,17]. The general conceptual framework for the proposed isolator characterization and corresponding real test equipment is shown in Fig.…”

“…6). Based on the theory of wave propagation in a rigid elastic environment, the transmission loss above the observed frequency band is greater [15,16,17]. It should be noted that as the excitation frequency increases, the transmission attenuation also increases.…”

Methodology of Prognostic Vibro-Acoustic Analysis of Buildings from Potential Dynamic Loads Generated by Rail Vehicles

“…The measurement was carried out at different speeds of several trams and at approximately the same running path of the railway track. The object of measurement was the selected measuring points of the scaffold bridge and the subgrade near the rail and support columns [6,9,11].…”