Lightweighting in BIW Component Systems

Integration and novel manufacturing processes helping OEMs shed weight

The body-in-white, or BIW, forms one of the most critical vehicle component systems in defining both the final external contour of a car and determining its crash worthiness. Acting as the basic skeleton of the car to which the other component systems are bolted/mounted, the BIW needs to perform varied functional strength characteristics. It needs to have enough strength-bearing characteristics while allowing for flexibility to mount different external skins as required. Add to this the requirement of impact crashworthiness from practically all sides, and it is not hard to understand why the design and vetting of BIW form such an important part of product development. In terms of mass impact, the BIW can weigh between 15% and 40% of the total vehicle weight depending on the design style, component integration, and inclusion of closures. This makes it an extremely vital component system in the radar for lightweighting, and it is arguably in the top-three focus areas for all OEMs to reduce the vehicle weight. However, the safety and inherent design aspects make lightweighting of the BIW a tricky path. Hence, OEMs have been choosing alternative materials and processes very carefully.