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In this study, a combined forming-structural analysis of composite structures was performed. Fiber orientation and shear angle changes of the composite materials during its thermo-compression molding processes were predicted with commercial software PAM-FORM. In addition, the material properties, such as elastic modulus and strength, from the shearing of woven fabrics, were measured. The predicted shear angle changes were transformed and reflected to the structural analysis by a self-developed vector-mapping program. The load-displacement curves of the composite structures from the combined forming and structural simulation were compared with the experimental compression and bending test results of hemispherical and U-shaped components, respectively. Finally, it was found that the mechanical behaviors of composite structures can be accurately predicted by the developed combined thermo-forming structural analysis method.

In this study, design optimization of a composite hood for automobiles was carried out to mitigate the impact of pedestrian head injuries based on finite element analysis. Reduced vehicle, headform impactor and single hood models were established to obtain optimal composite hood designs. The carbon fiber reinforced composite (CFRP) and the hybrid Glass fiber reinforced composite (CFRP/GFRP) laminates were selected as composite material candidates. Both stacking angle sequence and topometry of the composite hood were optimized based on the equivalent static load method. After the optimization, the head injury criterion (HIC), deflection and weight were measured to evaluate the performance of the composite hood. The developed CFRP and hybrid CFRP/GFRP type hoods with optimized final design exhibited the improved impact performance and significant weight reduction while satisfying bending and torsion deflection requirements compared to those of conventional steel and aluminum hoods.