Sandwich design makes bodies lighter and enhances crashworthiness



ThinKing December 2014 presents innovative concepts for vehicles with metal monocoque structures from the Institute of Vehicle Concepts at the German Aerospace Center (DLR)

The Development Agency for Lightweighting Baden-Württemberg presents this innovation in the December ThinKing. The Development Agency introduces innovative lightweight products or services from Baden-Württemberg in the “Thin King" every month.

The unladen mass of the entire lightweight vehicle will be not more than 400 kilograms (without batteries) and is designed for vehicles, such as quadricycles, in the L7e category. Under the management of engineers Simon Brückmann and Michael Kriescher the project has deliberately chosen to work with the L7e vehicle class because it is not subject to passenger vehicle restrictions and consequently offers more scope for innovations.

The skin for the prototype sandwich design body is made of aluminium and the core of cellular polyurethane. Crash stable structural adhesives and partial fastening and welding were used for jointing. As well as light materials, the overall mass was also reduced by integrating functions with just 50 elements. This allowed functions such as heat insulation or screw points to be integrated.

Sandwich materials are used in crash and load bearing vehicle structures. The composite sandwich panel construction is designed to crumple in a head-on collision and to absorb enough energy to ensure that vehicle occupants are not injured. The advantage is that the more the material folds, the greater is its plastic deformation and the more kinetic energy can be converted. Its integrity is preserved. The high stiffness of a specially developed vehicle front-end structure has already been demonstrated in crash tests at the Institute.

The scientists at the DLR have chosen to use aluminium and polyurethane as materials for the sandwich design. Both materials are relatively inexpensive and easily obtainable. They are also easy to process. Other combinations of materials could also be used

The safe light urban vehicle will be a lighthouse project and part of the Next Generation Car (NGC) research programme. NGC brings together the expertise of various DLR research institutes and can be expected to produce highly innovative research and development output. Further information about ThinKing is available at

About the Institute of Vehicle Concepts

The Institute of Vehicle Concept is a systems institute which carries out and coordinates transportation research on new vehicle concepts and technologies. The Institute’s areas of research include the development of future technical systems for sustainable, secure and affordable generations of road and rail vehicles. The Institute’s work ranges from design and planning through to construction, calculation, simulation and production of research demonstrations, components and vehicles.

About Leichtbau BW

Leichtbau BW GmbH is a public agency for the development and promotion of business and science in Baden-Württemberg. As a fully state owned company, Leichtbau BW operates as a neutral and cross-sector partner for commercial industries, research groups and society at large. The agency supports the transfer of lightweight technology and science and helps industry and research in their search for new cooperation partners.