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The engine subframe (cradle) is an important contributor to crash energy management in frontal impact for automotive vehicles. Subframe design can enhance vehicle crash performance through energy management. In addition to energy management targets, the subframe must meet stiffness, durability and other vehicle engineering requirements. Various subframe concepts are reviewed. Their design intents and vehicle performance are discussed. A development process of an aluminum subframe is then presented which details the subframe design as an energy absorbing component for frontal impacts. The architecture of the subframe is developed based on overall functionality requirements and package constraints. The geometry of the subframe is first designed to accommodate engine mounts and suspension support locations. The subframe member's shape, orientation, and location are then refined to accommodate the subframe-to-body connection requirements.

The crush resistance of roof structures is critical to minimizing injuries and enhancing occupant survival during rollover crashes. Federal Motor Vehicle Safety Standard FMVSS 216 requires the roof structure to resist a load equal to one and one half (1&1/2) the unloaded weight of the vehicle during the first 127 millimeters (five inches) of deformation. This paper discusses the analytical methodologies applied and challenges encountered developing a hybrid Aluminum-Random Chop Material (RCM) roof structure. The roof structure materials are extruded 6260T6 aluminum and RCM. This hybrid roof structure has to satisfy not only the FMVSS 216 roof crush resistance, but also packaging, torsional stiffness and head impact requirements. Due to packaging constraints, the structure has to be developed without the roof bow at the B-pillar level.