ADDITIVE MANUFACTURING AND MECHANICAL TESTING OF TOPOLOGY-OPTIMIZED CONTINUOUS CARBON FIBER REINFORCED THERMOSETTING COMPOSITES

Additive manufacturing (AM) of continuous carbon fiber reinforced composite (CCFRC) material is an emerging technology being explored to create complex structural designs with high specific stiffness and strength. However, obtaining a design that is informed by the manufacturing constraints of the process and provides achievable fiber tow path planning is a challenge. This paper presents the optimization of structural topology and fiber orientation with consideration of the constraints of the additive deposition of reactive resin infused fiber tows (ADRRIFT) process. A density-based method with solid orthotropic material with a penalization (SOMP) material interpolation scheme was used to optimize the structure’s topology and fiber orientation (TFO) for maximum stiffness. The Method of Moving Asymptotes (MMA) was employed to determine optimal material layout and fiber orientations for a continuous fiber tow given the manufacturing constraints of the process. An achievable print path was planned and realized for a dual UV-thermally cured acrylate-based resin and a 12K T1100 fiber tow using the Continuous Fiber 3D (CF3D®) process. Proposed optimal designs were developed for end-loaded cantilever and Messerschmitt-Bölkow-Blohm (MBB) beams. The structural stiffness of the optimized MBB beam increases by 85% using the proposed TFOO method. To validate the proposed optimization, fiber path planning, and CF3D® printing framework, MBB beams were manufactured and mechanically tested. The optimized design successfully translates to AM structures with 50% FVF with high specific strength and stiffness, good agreement between numerically predicted high stiffness values, and strength values that only varied by 2.5%.