Roof is one of the major subsystems of the Body-In-White Structure, which significantly affects the vehicle strength and durability performance criteria. The roof structure should meet the functional targets under the standard operating conditions. Roof design considering various parameters in the initial phase is beneficial in reducing the product timeline for the OEM. The first-time right approach provides an opportunity for Optimization and Cost benefits in the longer term.
This paper provides the use of Design for Six Sigma techniques to arrive at a robust and optimum design for the standard roof structure. The roof structure is designed to meet the operating conditions for durability. Roof finite element models are developed with control factors that affect the structure design. Virtual Analysis is performed on the Standard roof structure models. Roof Performance is the contribution of multiple factors such as roof material, thickness, number of roof bows, positioning of the bows, number of beads in the roof, section and height of the roof bows.
The paper looks at the contribution of each factor and shows how the combination of one or more factors can be effectively used to design an optimum and robust design that is light weight under the vehicle operating conditions. Standard roof is designed for Snow Load conditions. The final robust and optimized finite element design is validated for other durability loading conditions.