Investing Factors Affecting Door Slam Noise of SUV and Improved Performance by DFSS Approach

Recent development in automobile industries has seen increased customer attention for good door slamming noise. One of the constituent which plays major role in building brand image of vehicle in terms of NVH performance is door slam noise quality. Hence it is very desirable to understand how different door elements radiate sound during a door-closing event and how to optimize a door structure to achieve specific sound target in order to ensure the door closing noise quality, NVH engineers needed to look at contributions from different door subsystems. The use of statistical tools like Six Sigma can further help them to ensure the consistency in results. This paper explains the systematic approach used to characterize different element of door which contributes to the overall door slam noise quality through QFD (Quality Function Deployment) and contribution analysis. The different mechanisms contributing to door slam noise were studied. NVH characteristics (Acoustic transfer Function and Point Mobility) of the door structure and mounting locations were captured for correlating with the time - frequency spectrum of door slam event. Wavelet analysis was performed on door impact event to determine the critical frequency band contribute to noise. DOE (Design of Experiments) was constructed based on the analysis of results. Prototype modifications were conducted, the results of which are discussed in the paper together with their relative importance to work improvement in door closing noise. Finally the design intent solutions were developed together with component supplier and are validated on vehicle.