Vibro-Acoustic Analysis Using Segmented FEA and BEM
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Solution Overview
Problem
Existing methods for vibro-acoustic analysis of structures subjected to harmonic excitations are computationally intensive, require large resources, and are often ad hoc, prone to errors due to the need for human intervention and the combination of different software tools.
Innovation Solution
A two-stage approach combining finite element analysis (FEA) for steady-state dynamic responses and boundary element method (BEM) or Rayleigh approximation for acoustic analysis, using modal analysis, mode-superposition techniques, and damping adjustments to simulate acoustic fields efficiently, with parallel computing and low-rank approximations for faster solutions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional numerical methods are used to solve vibration and acoustic equations for structures with large number of FEA elements, then accurate acoustic responses can be obtained, but computational resources required become excessively large and computation time increases significantly
Solution Approach 1:
The patent segments the vibro-acoustic analysis into two distinct stages: (1) structural vibration analysis using FEA to obtain steady-state dynamic responses, and (2) acoustic analysis using BEM or Rayleigh approximation to calculate acoustic fields. This segmentation allows each stage to use the most appropriate method, reducing overall computational burden while maintaining accuracy.
Solution Approach 2:
The patent uses an integrated system that acts as an intermediary between FEA and BEM/Rayleigh methods. This system automatically performs modal analysis, extracts mode shapes and frequencies, applies mode-superposition techniques, and transfers results between the structural and acoustic analysis stages, eliminating the need for manual intervention and reducing computational overhead.
2Adaptability or versatility
If ad hoc approaches combining different software tools are used for vibro-acoustic analysis, then flexibility in method selection is achieved, but human intervention is required and errors increase
Solution Approach 1:
The patent merges FEA, modal analysis, mode-superposition techniques, and BEM/Rayleigh approximation into a single integrated system. This unified approach maintains the flexibility of selecting different acoustic methods (BEM or Rayleigh) while automating the entire workflow from structural vibration to acoustic field calculation, eliminating manual intervention and reducing errors.
Solution Approach 2:
The integrated system provides universal functionality by handling both structural vibration analysis and acoustic field calculation in one platform. It supports multiple acoustic analysis methods (BEM and Rayleigh approximation) and automatically performs intermediate steps like modal analysis and mode-superposition, making the system adaptable to different problem types without requiring separate software tools.
3Ease of operation
If FEA is used for both structural vibration and acoustic field calculation, then a unified approach is achieved, but computational intensity becomes excessive for large-scale problems
Solution Approach 1:
The patent segments the analysis domain and methodology: using FEA for structural vibration analysis where it is most efficient, and switching to BEM or Rayleigh approximation for acoustic field calculation where these methods are more computationally efficient. This segmentation maintains ease of use through automated integration while dramatically improving productivity for large-scale problems.
4Productivity
If modal analysis with mode-superposition technique is used to obtain steady-state dynamic responses, then computational efficiency is improved, but damping adjustments are required to match real-world behavior
Solution Approach 1:
The patent employs parameter changes by allowing adjustment of damping ratios for each mode in the mode-superposition analysis. This enables the model to match real-world damping behavior by tuning the damping parameters while maintaining the computational efficiency of the modal analysis approach. The system calculates undamped mode shapes and frequencies, then applies appropriate damping adjustments to achieve accurate predictions of vibratory response.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enables effective and efficient vibro-acoustic analysis by reducing computational intensity, minimizing errors, and providing accurate simulations of acoustic responses, suitable for applications like NVH analysis of vehicles.
Implementation Method 1
The finite element method (FEM) (sometimes referred to as finite element analysis (FEA)) is a numerical technique for finding approximate solutions of partial differential equations (PDE)
Implementation Method 2
boundary element method (BEM) has emerged as a versatile and powerful tool for solving engineering problems. BEM is a numerical method for solving boundary-value or initial-value problems formulated by using boundary integral equations
Implementation Method 3
Second, an acoustic analysis is conducted according to Helmholtz equation using the nodal velocities obtained at desired locations on the structure as a boundary condition
Implementation Method 4
A two-stage approach combining finite element analysis (FEA) for steady-state dynamic responses and boundary element method (BEM) or Rayleigh approximation for acoustic analysis, using modal analysis, mode-superposition techniques
Implementation Method 5
A two-stage approach combining finite element analysis (FEA) for steady-state dynamic responses and boundary element method (BEM) or Rayleigh approximation for acoustic analysis, using modal analysis, mode-superposition techniques, and damping adjustments
Data Source
AI summary
Methods and systems for simulating acoustic field resulted from particular excitations by performing vibro-acoustic analysis of a structure are disclosed. According to one aspect of the present invention, vibro-acoustic analysis of a structure is performed in two stages. First, steady state dynamic (SSD) responses are obtained using a finite element analysis model of a structure subject to harmonic excitations (e.g., external nodal loads, pressures, or enforced motions (e.g., ground motions), etc.). The steady state responses are the results (e.g., nodal velocities at desired locations of the structure) obtained in a finite element analysis in frequency-domain. Second, an acoustic analysis is conducted according to Helmholtz equation using the nodal velocities obtained at desired locations on the structure as a boundary condition. The acoustic analysis can be performed in a number of procedures (e.g., boundary element method, Rayleigh approximation method, etc.).