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This paper describes the work undertaken by BMW with assistance from Alcan to examine the manufacture and performance of stamped sheet monocoque Body-In-White structures. A range of component and structure trials was conducted culminating in the manufacture and test of a small number of vehicles based on the current BMW 3-Series architecture. This programme illustrated that substantial weight saving could be achieved whilst maintaining the necessary level of structural performance.

The strong interest in producing lightweight car bodies in aluminium has prompted the need to understand the behaviour of typical crash members fabricated using mainly AA5000 and AA6000 materials. In studying the sometimes complex impact load cases, it is often useful to examine the axial and bending collapse modes seperately in order to assess the geometric and material influences, and this is the approach taken in this paper. A number of organisations have reported various mechanistic approaches to predicting performance in axial and bending collapse, and our method has been to assess, and where necessary, refine the best of these for aluminium sections in order to produce effective design guidlines for the automotive industry. This work is largely complete for axial crush and examples of design application from concept to structural testing are given.

The paper describes problems and suggested solutions in use of adhesive bonding for joining aluminum structures. Different ways to model and analyse a bonded joint are presented along with discussion on various advantages and drawbacks. As an example, the modelling and experimental results of a design exercise on a vehicle front cross-member are presented. The use of detailed joint modelling in determining the influence of local joint geometry on both adhesive and metal stresses is also demonstrated.

As part of the development of Aluminum Structured Vehicle Technology (ASVT), significant advances have been made in the design of impact energy absorbing members for automobiles. This paper compares the performance of aluminum and steel impact members, and discusses the influence of the material properties of aluminum on subsequent impact member performance. Methods for designing aluminum impact members for stability, collapse initiation and subsequent collapse performance are presented. This includes both analytical and finite element modelling.