Mechanical performance of highly loaded tow reinforced hybrid-molded composite structures

Continuous fiber tow reinforcements in hybrid-molded composite structures are an emerging means of replacing structural, high production volume metal components, but further study of design variable effects is critical to widespread adoption. By testing representative structures with features found on automobile components, performance was evaluated for a range of material combinations and reinforcement content. Tow reinforcements were made from continuous glass or carbon fiber reinforced PA6 prepreg tape and injection overmolded with unfilled or glass fiber filled PA6 adding a shear web and rib structures. Tow reinforcement significantly reduced warpage and in tensile loading, demonstrated potential for 340% strength increase over parts without tow. However, three-point bend performance was dominated by the overmolding material. High strain to break overmolding materials are recommended to avoid premature overmolding material cracking.

Automated summary

Continuous fiber tow reinforcements in hybrid-molded composite structures have the potential to replace high production volume metal components, but further research on design variables is needed. Testing representative structures with automotive component features, different material combinations and reinforcement content were evaluated. Tow reinforcements significantly reduced warpage and showed a potential strength increase of 340% in tensile loading. However, the performance in three-point bend tests was influenced by the overmolding material, and it is recommended to use high strain to break overmolding materials to prevent premature cracking.