3D printed modular Bouligand dissipative structures with adjustable mechanical properties for gradient energy absorbing

Abstract 3D printing enables the creation of intricate, layered structures with specific micro and macro architectures that cannot be achieved through traditional methods. By designing 3D structures with geometric precision, selective regulation of mechanical properties can be achieved, allowing for efficient dissipation of mechanical energy. In this study, a series of modular samples inspired by Bouligand structure were designed and produced through a direct ink writing system along with a classical printable polydimethylsiloxane (PDMS) ink. By changing the angles of filaments in adjacent layers of these modular samples (from 30° to 90°) and the filament spacing during printing (from 0.8 mm to 2.4 mm), they show adjustable mechanical properties. Compression mechanical testing revealed that the 3D printed modular Bouligand structures exhibit stress-strain responses that enable multiple regulation of elasticity modulus from 0.06 Mpa to over 0.8 Mpa. The mechanical properties were regulated over 10 times in printed samples prepared using homogeneous materials. The gradient control mechanism of mechanical properties during this process was analyzed using finite element analysis. Lastly, 3D printed customized modular Bouligand structures can be assembled to compose an array with Bouligand structures show different orientations and interlayer details according to specific needs. Begin with decomposing the original Bouligand structure to achieving modular 3D printing, and then assembling the modular samples into a special Bouligand structures array, this research will providing parameters for achieving gradient energy absorption structures.