Development of reduction model for Dynamical Energy Analysis and model estimation by using Transfer Path Analysis

Abstract

Dynamical Energy Analysis (DEA) has been introduced as a mesh-based high frequency method modelling structure borne sound for complex built-up structures. This has proven to enhance vibro-acoustic simulations by making it possible to work directly on existing finite element meshes circumventing time-consuming and costly remodeling strategies. In addition, DEA provides detailed spatial information about the vibrational energy distribution within a complex structure in the mid-to-high frequency range. DEA has been used to calculate the structure borne sound of an assembled agricultural tractor and good agreement between measurements and DEA calculations has been shown. In particular, it has been demonstrated that DEA can model shell structures accurately. However, it is still difficult to model a solid structure because currently DEA is based on wave transmission calculations through plate/plate junctions. Additionally, accurate FE meshes of assembled complex structures are often not available due to the uncertainties of modelling welds, bolts and rubber bushes between components. We propose here to integrate measurement data into DEA to improve the effectiveness of DEA modelling. Advanced Transfer Path Analysis (ATPA) is employed to extract energy transmission characteristics of a structure. The direct transfer functions between interface points are calculated using ATPA based on measured frequency response functions. DEA elements connecting interface points and representing energy transmission characteristics of the structure are created based on the ATPA result. The proposed method is verified with a finite element model of a simple structure.