Design and optimization of sinusoidal-grid infill for 3D printed continuous fiber composite structures

Additive manufacturing technology is often used to manufacture complex structures. With this technology, continuous fibers can be printed flexibly. In this study, a grid filling method for 3D printing continuous carbon fibers is proposed. This method enables the carbon fibers to obtain a good orientation by changing the relevant parameters of the sinusoidal curve. A grid filling structure composed of multiple sinusoidal curves was designed, which could freely set the number of the curves. The sinusoidal grid can be further optimized using a variable-density method, which can adjust the grid density based on stress distribution. The test results indicate that the variable-density method can effectively enhance the sinusoidal grid structures. This path planning method provides more possibilities for 3D printing of continuous carbon fiber composite structures.