Automotive Buzz Squeak and Rattle Mechanisms Analysis Evaluation and Prevention.pdfVIP

Automotive Body Structure Enha R Bas Lohitsa Inc. 2285 Copyright ? 2001 Society of Automotive Engineers, Inc. ABSTRACT Today, the interior noise perceived by the occupants is becoming an important factor driving the design standards for the design of most of the interior assemblies in an automotive vehicle. Buzz, Squeak and Rattle (BSR) is a major contributor towards the perceived noise of annoyance to the vehicle occupants. An automotive vehicle consists of many assemblies such as instrumentation panel, doors, sun/moon-roof, deck lids, hood, etc. which are the potential sources of BSR noise. The potential locations of critical BSR noise could be contained within such assemblies as well as across their boundaries. An extensive study is made regarding the overall structural behavior as well as their interaction under typical road loads to come up with enhanced design for improved quality from the BSR noise perspective. The alternative designs were comparatively evaluated for their relative noise level from buzz, squeak and rattle perspective using an analytical tool - N-hance.BSR. Critical noise sources both at the system as well as the assembly levels were identified and the relative noise levels were compared critically to determine the influence of the design changes on the BSR quality of the system and its assemblies. In this paper, a brief introduction is provided regarding the typical product background and the noise quality requirements, typical design changes that influence the BSR characteristics followed by a brief introduction to the software N- hance.BSR. The results of such a comparative design evaluation from N-hance.BSR are presented at the end. The observations of the critical squeak and rattle locations were confirmed by physical tests on the baseline and enhanced models. INTRODUCTION Squeak Rattle is an important warranty sensitive attribute for OEMs. It also affects perceived quality of the vehicle. Struc