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Due to the trend to build more vehicle models on a common platform, body development is very often on the critical path in the automotive development process. While the virtual assessment of attributes like crash, structural rigidity or production feasibility is common practice today, it is done less systematically for NVH and durability. They are traditionally only considered close to the availability of prototypes. Performance issues discovered at this stage will lead to additional design cycles which conflicts with the need to further shorten the total development time. The process proposed in this paper results in a better initial design by doing more NVH analysis in the pre-CAD phase and a reduced number of iteration cycles required for NVH and durability engineering by iterating much faster to the final design. Mesh morphing and beam concept analysis make it possible to evaluate and optimize functional performance characteristics based upon predecessor FE models.

Vibro-acoustic simulation methods such as FEM and BEM have made an enormous progress for modelling and describing the acoustic and vibro-acoustic behaviour of mechanical systems. In order to make these techniques truly become part of the “virtual” industrial design process however, the specific challenges related to industrial-sized problems must be overcome. The paper reviews the critical issues to building and solving large-scale problems and discusses practical aspects such as the correct load definition and simulation performance requirements and improvements. Some breakthrough solutions like Acoustic Transfer Vectors and parallel computing are discussed. Specific attention is devoted to the potential of hybrid methods combining virtual models with experimental data. The discussed are illustrated by means of powertrain noise and vibration case studies.

The paper addresses the problem of NVH development of vehicles. An approach for the specification and assessment of subsystem performance as well as of the early part of the integration process is presented hereto. The basic technologies applied are those of Transfer Path Analysis and System Synthesis. Various applications to industrial problems are discussed.

For the prediction of the vibro-acoustical vehicle behaviour up to higher frequency ranges, modal approaches are not very applicable. Hybrid frequency response function based substructuring methods are therefore proposed, in which the high modal density components are represented by experimental data, and in which the lower density components are represented by finite element models. The frequency response function synthesis of the lower denstty component can be based on modal synthesis. In this paper, an application of coupling a rear twist beam suspension with a car body is discussed. In this case the vibro-acoustical behaviour of the car body is the high density component, the low density component is the suspension finite element model. Aspects of accuracy, related to truncation, influence of rotational degrees of freedom, symmetry of the experimental matrix, and prestraining of the suspension springs are discussed.