Strength and toughness enhancement in 3d printing via bioinspired tool path

Mechanical properties such as strength, toughness and anisotropy are significant in 3D printing technology. Unfortunately, the strength and toughness are often mutually exclusive, and are therefore difficult to be enhanced simultaneously. Here, a bioinspired parallel-scan path is proposed to increase both the strength and toughness with in-plane isotropy. In this method, a Bouligand structure is adopted to increase the fracture deflection and energy absorption. Result shows that at the optimal rotational angle 15 degrees, the ultimate strength and toughness can be improved over 12% and 100%, respectively, along with good in-plane isotropy. To investigate the mechanics of the improvement, the fracture surface is analyzed and the finite element (FE) simulation is performed. Our results suggest that the optimal mechanical properties can be obtained at a certain rotational angle by controlling the stress under a moderate level, and maximizing the fracture surface during its propagation. The method is simple and highly adaptive, and may offer a good mechanical reinforce capability in extrusion based 3d printing. (C) 2019 The Authors. Published by Elsevier Ltd.