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An existing system-level Statistical Energy Analysis (SEA) model of an enclosed operator station (cab) for a combine-harvester was improved through component-level analyses using Finite Element (FE) and hybrid FE-SEA methods. At mid to high audio frequencies, airborne transmission of machine noise is a dominant path for the cab. An SEA model was created for the cab using the VA One product. When model results were validated against experimental data derived from three idealized insonification load cases, the original model did not compare well with the measured data. The structural panels used in the cab feature various non-uniform cross-sections and varying radii of curvature. The former are not appropriately modeled with standard beam stiffeners, and the latter must be accounted for by some average curvature. Geometrically accurate Finite Element (FE) models of the panels were employed to estimate parameters including effective material stiffness, and effective material density.

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.