Design and automated manufacturing of profiled composite driveshafts

The high specific strength and stiffness characteristics of composite materials such as carbon fiber-reinforced plastic (CFRP) allow a significant weight reduction of the structural machine components such as automobile driveshafts. But high material cost and rather low productivity of the established manufacturing processes (e.g., filament winding) often inhibit the use of CFRP components in a high-volume car series. In this paper, a novel composite driveshaft system based on a profiled CFRP tube is presented. This system is designed to be produced by a continuous pultrusion process to achieve a significant reduction of the manufacturing costs. A cost assessment study was conducted to quantify the benefit of the developed continuous manufacturing process. In comparison with the state-of-the-art filament winding process, a cost reduction of 36% for the composite shaft body can be obtained. Moreover, the proposed fiber layup processes – braiding and continuous winding – offer the potential to manipulate the reinforcement architecture to maximize material utilization without reducing the manufacturing efficiency. This potential is investigated and validated by experimental tests. A difference in the load bearing capacity of more than 100% between different reinforcing architectures is shown.