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The prediction of sound levels in vehicles and the environment is now a common practice in automotive engineering. This has been made possible by the development of powerful tools based on boundary element techniques. These “first generation” systems provided the user for the first time with easy to use tools to predict sound levels which result from any known set of vibrations of the panels surrounding the acoustic region. This paper will describe a “second generation” acoustic system based on boundary elements, which not only enhances the accuracy of the modeling, but also provides powerful diagnostic facilities to enable the user to identify the main contributions to the sound intensity at any point of interest. Applications are presented, and include a classical automotive engineering problem in which the software system identifies the body panels which contribute most to the noise level at the driver's right ear.

The boundary element method (BEM) has become established as a powerful alternative to finite element modeling for a variety of automotive engineering solutions. In particular, it has been effective in the static analysis of powertrain components and also for the acoustic analysis of both the passenger compartment and the air-space surrounding a vehicle. While the technique offers a substantial improvement in case of use and modeling times for many problems, especially those described above, and also produces highly accurate solutions, the only drawback of the BEM has been its somewhat more limited range of analysis types. This paper describes how the Dual Reciprocity BEM technique has been applied in a commercial BEM package to offer a solution for dynamic analysis.

A previous paper presented by the author at the 5th International (8) Conference on Vehicle Structural Mechanics dealt with the elastostatics analysis of automotive structures. That work helped to establish BEM as an efficient alternative to FEM analysis for automotive components design. The present paper demonstrates some of the new capabilities available in BEM codes which are essential for CAD applications and the eventual integration of the technique within the CIH process. In addition, the paper deals with the application of new theoretical developments which allow the extension of the method to time dependent problems, i.e. time dependent thermal and elastodynamics analysis. These are important applications in vehicle components but their efficient and accurate BEM solution was not possible until very recently. The paper also presents some quality and reliability tests carried out comparing BEM with FEM and other solutions. They tend to confirm the overall efficiency of the BEM.