Structural Design, Fabrication, and Vibrational Response of a Composite Space Frame

Continuous-fiber composite materials are currently being evaluated as replacement materials for conventional steel alloys for primary load-carrying members of automotive structures. The objective of this study was to design and fabricate a composite space frame based on a targa-top body configuration. The present paper summarizes the overall structural design, fabrication, and vibrational response of the space frame. Initial structural optimization studies based on elastic load conditions were completed for the structure. Subsequent studies were directed toward redesigning the fiber orientation and thickness of the space frame beams to account for fabrication limitations and frontal impact loads. The frequency response of the composite structure was also determined computationally and experimentally and compared to the response of an optimized mild steel space frame. The results presented in this paper show that a composite space frame based on a targa-top configuration can be constructed using continuous-fiber materials to achieve mass reduction over a steel design while meeting performance criteria for frequency and frontal impact loads.