Eksperimentalni dinamski modeli podstruktur v metodah analize prenosnih poti : doktorsko delo

slovenian

doktorska dela

2023

dissertations   dynamic substructuring   expansion methods   frequency domain   frequency response function   structural dynamics   transfer path analysis

Univerza v Ljubljani, Fakulteta za strojništvo
(Obvezni izvod spletne publikacije)

In the dissertation, we discuss the issue of incorporating consistent experimental dynamic models for the requirements of transfer path analysis, which investigates the transmissions of noise and vibrations from the excitation source to passive parts of structures. In the first part of the thesis, we focus on the introduction of new measurement approaches to transfer path analysis methods. As an alternative to established methods, a hybrid method of acoustic holography and laser vibrometry was proposed to determine the vibration response of the structure. In addition to the non-contact measurement, this method also offers the possibility to combine different physical domains (sound pressure and velocity). The second part of the thesis addresses the uncertainty of the impact location, which is a significant source of uncertainty in the transfer path admittance. In this work, a procedure for characterising the uncertainty of the location of structural excitation is proposed, based on sensitivity analysis. It is estimated how small variations in the location of an individual impact affect the completeness of the forces acting in contact between the active and passive substructures during operation. In the third part, an original method for measuring the frequency response functions of actively excited structures during their operation is presented. Since the active structure of the assembly is characterised independently of its final assembly, this part presents a method for evaluating the response function of the assembly based solely on measurements of its response.

15.05.2023