Variable axial composite light weight automotive parts using anisotropic topology optimization and tailored fiber placement
2022-01-0408
03/29/2022
- Event
- Content
- Continuous fiber composites are an important material for realization of lightweight structures. In the last decade, there has been great progress in fabricating continuous fiber composite parts in terms of local fiber orientation control by robotics and the additive manufacturing technologies. These technologies include continuous fiber printing (CFP), tailored fiber placement (TFP) and automated fiber placement (AFP). One common challenge of these technologies resides in the design method. These methods can fabricate local orientation-controlled composites, so called variable axial composites (VACs), which show great performance improvement when appropriately designed for given loading conditions; however, they may not be as robust as conventional quasi-isotopic composites due to misalignment of load path and fiber path. Therefore, design of both structure and fiber orientation considering load conditions is highly critical and demands high engineering skills. To address this situation, we propose a method for simultaneous automatic design of the structure and fiber orientation by extending topology optimization using orientation tensor-based design variables. By independently controlling components of orientation tensor while keeping tensor invariants constant, optimal local material orientation distribution is obtained. The obtained design can be translated to path layouts manually or automatically by additional algorithms. Among various VAC fabrication methods, the TFP shows a good balance between fiber control resolution and production throughput, as well as offering speed and a range of forming process choices. In this paper, we present a case study of automotive part prototyping of a rear wing support pillar structure. The conventional part is made of die-cast aluminum weighing 425 g. The prototype is designed using anisotropic topology optimization and fabricated with TFP and vacuum-assisted resin transfer molding (VaRTM) using a silicone mold cast from 3D-printed die. The fabricated prototype weighs 119 g, a 71% weight reduction, achieving 3.5x mass-specific stiffness improvement.
- Citation
- Nomura, T., Iwano, Y., Kawamoto, A., Yoshikawa, K. et al., "Variable axial composite light weight automotive parts using anisotropic topology optimization and tailored fiber placement," SAE Technical Paper 2022-01-0408, 2022, .