Quantifying Door Closing Sound Quality, Measurement Techniques and Influence of Selected Parameters

Abstract

Door closing sound is one of the most influential parameters to the customer while buying a car. It is one of the first impressions one can get while interacting with the vehicle and this contributes to the overall quality perception. Thus, it is very interesting for automotive developers to understand the influence of several parameters on the door closing sound quality. Various experimental and simulation research has already been performed in this field.This thesis is focusing on the experimental part, where classical methodologies, such as standard vibration and acoustical measurements were applied. However, alternative methods, like the acoustic camera, have hardly ever been used. The acoustic camera is typically implemented to measure stationary sound sources. On the other hand, the door closing sound is a transient phenomenon. In this thesis, both, the classical and the acoustic camera approach were used to develop a methodology to quantify the door closing sound quality. The measurements with the acoustic camera identified various sound sources, distributed over the complete door. The main hot-spots are localized at the striker and around the junction of the upper rail and the B-pillar. The other sources are less contributing to the overall door closing sound. These results have been used to choose adequate measurement positions for accelerometers and were ultimately verified by the classical approach. Based on that, the influence of variations of the door seal stiffness and the inclination of the car were investigated. The main outcome of this was that the door closing sound can be damped or amplified within certain frequency ranges by changing these parameters.