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This paper describes the work carried out to assess the structure-borne and airborne contributions in the Rieter APAMAT II testing machine. The APAMAT II system was designed to measure the effectiveness of various trim and barrier treatments in automotive interior applications. The individual structure-borne and airborne contributions from the ball impact on the treated panel cannot be obtained directly from the sound pressure level measurements in the receiver chamber of the system. A hybrid modeling technique is proposed that incorporates finite element (FE) and statistical energy analysis (SEA) methods to develop vibro-acoustic models across the entire frequency range for analyzing transmission characteristics of various trim configurations. This provides an analytical model that can adequately predict the vibro-acoustic response under structure-borne loads at low to mid frequencies.

In the early stages of a vehicle program, sound package design is significantly complicated by numerous competing requirements including cost, weight, acoustical targets and packaging space. The problem is further convoluted due to a limited definition of the vehicle at this time. In this article, a Statistical Energy Analysis (SEA) model of the vehicle is created based on a gross description of the vehicle architecture. A large material database of commonly used sound package configurations is then linked to the SEA model. Genetic Algorithms (GA) are finally applied to optimize the sound package design to satisfy cost, weight, acoustical targets and packaging requirements in the vehicle design.

SAE acoustics materials committee published updates of SAE J1400 Standard - Laboratory Measurement of the Airborne Sound Barrier Performance of Flat Materials and Assemblies in 2017. In the standard, a control sample is defined with a specific construction to determine the suitability of the test suite. A set of measured sound transmission loss data of the control sample are included in the published updated standard. Autoneum North America Acoustics Laboratory constructed a control sample based on the design in the standard. Sound transmission loss (STL) measurement of this control sample was performed and results are consistent with published data below 2000 Hz. Above 2000 Hz, STL results are above published limits. Sound intensity measurement and flanking noise paths measurements confirmed the measured STL values of the control sample.