Search

Es wurde die Schallentstehung an einem Autokühler (56 x 40 x 15 cm) mit Ventilator (Ф42 cm) in einer Labormessung am weich aufgehängtem Kühler untersucht, wobei verschiedene Verfahren zur Schallquellenortung getestet wurden. Es wird über die Messungen, deren Ergebnisse und deren Probleme berichtet, die sich aus der Luftströmung und aus dem 3-dimensionalen Messobjekt (15 cm Dicke) ergeben. Die Messung wurde durch DELPHI Powertrain Systems Luxemburg initiiert und von dort begleitet. Die Interpretation bezüglich der Schallentstehung ist nicht ganz eindeutig.

Impact driving, pressing and vibrodriving are the three main methods to drive sheet piles. The sound level generated during vibrodriving varies almost between the very high level of an impact driving and the lowest sound level of a pressing. In the first part of this doctoral thesis, sound measurements feasibility is thoroughly studied. Particular attention is paid to the measurement conditions on construction sites and to the measurement methods (sound power level, beamforming and thermography). These methods are outlined and the provided results are compared. In addition, the different causes of noise are analysed and the influence of various parameters is quantified. In the second part, the acceleration measurements of the full-scale experiments are used to calibrate a Finite Element model. A parametric study analyses how the most important mechanical parameters influence the noise level. This research has shown that a decrease of the noise generation on construction sites can be obtained by two ways: by recommendations for installation of sheet piles at the construction site, and by requirement of constructive measures that significantly reduce the noise level.