High-frequency structure- and air-borne sound transmission for a tractor model using Dynamical Energy Analysis

Abstract

Dynamical Energy Analysis (DEA) is a mesh-based high frequency method for modelling structure borne sound in complex built-up structures. Vibroacoustic simulations are performed directly on finite element meshes, circumventing the need for remodelling strategies. DEA provides detailed spatial information about the vibrational energy distribution within a complex structure in the mid-to-high frequency range. We will present here progress in the development of the DEA method towards handling complex FE-meshes including Rigid Body Elements and sound radiation. We also provide, for the first time, a detailed comparison of the simulations with measurements on a complex engineering structure consisting of the chassis and cabin of a tractor. Both structure borne vibrations and sound pressure levels (SPL) inside the cabin were considered. For the latter, a combined DEA/SEA analysis has been developed. The simulation results compare favourably with measurement results, both for vibration levels measured across the structure and for SPLs inside the cabin.

Wireless power distributions in multi-cavity systems at high frequencies

“…Given the close agreement between DEA and RT, this may serve as an indirect validation of DEA compared to full wave methods in the context of EM fields. Moreover, DEA has been validated by both FEM simulations [ 60 ] and measurements [ 10 ] of structure-borne sound transmission. Further research is ongoing to validate RT and DEA predictions for EM wave propagation.…”

“…Ray tracing is efficient as long as the number of possible reflections taken into account is small, but may become inefficient in reverberant environments. Recently, a mesh-based ray tracing solver called Dynamical Energy Analysis (DEA) [ 9 , 10 ] has been developed. It approximates wave energy transport using energy flow equations written in terms of so-called linear transfer operators, here formulated as a boundary integral equation computing power fluxes through interfaces.…”

“…The method has been introduced first in 2009 [ 9 ] and has been refined over the years, mainly for applications in vibro-acoustics. It is now able to run on grids of several million elements in 2D [ 10 , 11 , 51 , 52 ] and has been extended to 3D [ 12 , 53 ]. DEA interpolates between PWB and a full RT analysis when increasing the basis size.…”

Efficient Statistical Model for Predicting Electromagnetic Wave Distribution in Coupled Enclosures

“…Such a presumption no longer holds when the loss of the cavity wall becomes so high such that the energy distribution near the system boundaries and from the input to the output aperture drop considerably. In this case, PWB needs to be replaced with other methods such as ray tracing [36] or the DEA analysis [39] or, in the case of multiple scatterers in each cavity, using an approximate flow solver based on a 3D diffusion model [65]; all these methods have a larger computational overhead compared to PWB. Strong damping also violates the random plane wave hypothesis crucial to the RCM [57,62,66].…”

“…The PWB method is based on the assumption of a uniform field distribution in each cavity which is often fulfilled in the weak inter-cavity coupling and low damping limit. Extensions of the PWB method that drop the uniform field assumption are ray tracing (RT) methods [35,36] or the Dynamical Energy Analysis (DEA) method [37][38][39] which calculate local ray or energy densities. DEA and RT capture non-uniformity in the field distribution within a given sub-volume.…”