The WBM is developed in the Noise and Vibration Research Group by:

• prof. dr. ir. Wim Desmet: initiator of WBM research
• prof. dr. ir. Dirk Vandepitte: WBM supervisor
• prof. dr. ir. Paul Sas: WBM supervisor

• dr. ir. Bert Pluymers: vibro-acoustics, acoustic radiation, hybrid acoustic WB-FE
• dr. ir. Bert Van Genechten: hybrid vibro-acoustic WB-FE, multi-level approach
• ir. Bart Bergen: acoustic radiation, hybrid methodologies
• ir. Karel Vergote: 3D structural coupling, solid mechanics, stochastic modelling
• ir. Elke Deckers: solid mechanics, porous materials
• ir. Onur Atak: hybrid vibro-acoustic WB-FE, model reduction techniques, hybrid BE approaches
• ir. Stijn Jonckheere: porous materials, hybrid schemes
• dr. ir. Joong Seok Lee: porous materials, hybrid unified modelling approaches
• ir. Antonio Maressa: hybrid FE-WB modelling, industrial applications

• dr. ir. Caroline Vanmaele
• dr. ir. Bas van Hal
• dr. ir. Ravish Masti

Please don't hesitate to contact us for more information.

• Conference and Journal Publications
• PhD publications

• EU FP7 Collaborative Research Project, MID-MOD: Mid-frequency vibro-acoustic modelling tools - Innovative CAE methodologies to strengthen European competitiveness
• EU FP7 Marie Curie Initial Training Network (ITN), MID-FREQUENCY: CAE Methodologies for Mid-Frequency Analysis in Vibration and Acoustics (coordinator)
• IWT Project no.IWT-070337: MIDAS: Next generation numerical tools for mid-frequency acoustics
• EU FP6 Marie Curie EST project SIMVIA2: Advanced and New simulation methods in vehicle vibro-acoustics – Scientific analysis, experimental verification and development of methodologies fo the industrial application (website)
• FWO Project no.G0350.05: Development and validation of hybrid substructuring techniques for acoustic simulations
• EU FP6 Marie Curie project EDSVS II: European Doctorate in Noise and Vibration Studies (website)
• IWT Project no.IWT-040433: Analysis Leads Design - Frontloading Digital Functional Performance Engineering
• FWO Project no.G0123.01: Design and development of a prediction technique for the analysis and optimisation of the low- and mid-frequency dynamic behaviour of complex vibro-acoustic systems

Numerical simulation of vibro-acoustic systems is usually done by finite element or boundary element methods. Both deterministic techniques are based on an element discretisation of the problem domain or its boundary surface. The dynamic variables within each element are expressed in terms of simple (polynomial) shape functions, which do not satisfy the governing dynamic equations. These element based methods are well suited for the dynamic analysis of arbitrarily shaped (vibro-acoustic) systems, but their use is practically restricted to low-frequency applications. At higher frequencies, structural and acoustic wavelengths become so small that a prohibitively large number of elements and computational effort would be required to get reasonable prediction accuracy.

In order to extend the applicability of numerical prediction techniques towards vibro-acoustic analysis at higher frequencies, the PMA division has developed a wave based method (WBM). The WBM is a deterministic technique, based on the indirect Trefftz approach. Instead of using locally defined element shape functions, the WBM applies globally defined wave functions, which do satisfy the governing dynamic equations. The vibro-acoustic response of the system at a certain frequency is expressed as a summation of wave function contributions, which result from an integral formulation of the problem boundary conditions.

The WBM exhibits better convergence properties than the element methods resulting in smaller model sizes and computational efforts. However, the WBM is most efficient for systems of moderate geometrical complexity. The WBM has been successfully applied for the steady-state analysis of bounded and unbounded acoustic problems, for the vibration analysis of flat plate assemblies and for the study of vibro-acoustically coupled systems. Furthermore, the applicability of the WBM has been extended to problems of arbitrary geometry by the development of hybrid coupling schemes with finite elements. These hybrid approaches aim at combining the benefits of both techniques, namely the high computational efficiency of the WBM and the geometrical flexibility of finite element methods.

Currently, research activities focus on five items:

• optimisation of the hybrid schemes by making use of state-of-the-art finite element technologies;
• investigation of a multi-level WB modelling approach for efficient modelling of concave shapes;
• extension of the unbounded acoustic WB methodology towards transmission and multi-fluid problems;
• investigations towards structural intensity and power flow analysis with the WBM;
• and application of the WBM for the analysis of porous materials.