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This paper presents the development of a structural model for passenger car tyres, based on a three-dimensional flexible ring on an elastic foundation. The ring represents the belt and the elastic foundation represents the tyre sidewall. The tyre model, which is implemented as a finite element model, is valid below the first treadband axial bending mode and includes a definition of the wheel flexibility and air cavity. The eigenfrequencies predicted by the model are within 5% of the measured eigenfrequencies. The model is validated by comparing predicted with measured responses for both an unloaded and loaded tyre.

The reported investigations aimed at adopting and verifying numerical prediction methods for the determination of the efficiency of engine sound shields. An extended measurement series and parallel Boundary Element calculations were conducted on a simple engine simulator with various engine shields. The effect of the shields was expressed in terms of spatially averaged, narrow band Insertion Loss spectra. It was found that the efficiency of sound shields is determined by complex interactions between the source and its surroundings. These effects could be better understood and reasonably well predicted by using the BE method. The relative IL quantity can be calculated more accurately than the absolute sound field descriptors themselves.

When categorising the available ecodesign tools according to the methodological design phases and steps, most design for environment tools prove to be analysis oriented and mainly suitable for the final, detailed design phases. This paper emphasises emerging methods allowing the integration of environmental issues earlier in the design process and in a more pro-active way. These methods are based on a context sensitive access to structured guidelines and examples. Finally, the integration of these pro-active tools in a holistic life cycle design system, including also analysis techniques such as life cycle assessment, is shortly described.

The identification of the contributions of airborne noise sources in vehicles in operational driving conditions is still a cumbersome task. Whereas the measurement of the transfer path from possible noise sources to the observer ear locations is efficient and accurate in most conditions, the source strength identification is still a challenging task. This paper presents the basic concepts of a new source quantification technique based on acoustic pressure measurements close to the operating sources. The main goal of developing a new technique is to achieve a faster and more economic method as compared to existing methods.

Tire noise has become a predominant contributor in many traffic noise situations nowadays and hence, the demand for accurate tire noise prediction models is high. A rolling tire is experimentally characterized by means of the substitution monopole technique: the running tire is substituted by the non-operating tire covered by monopoles. All monopoles have mutual phase relationships and a well defined volume velocity distribution which is derived by means of an inverse Airborne Source Quantification technique; i.e. by combining static transfer function measurements with operational indicator pressure measurements close to the rolling tire. Models with varying amounts and locations of monopoles are discussed.