In-Plane-Compression Mechanical Behavior of Selective Laser Melting Titanium Alloys’ Self-Similar Honeycomb

The work proposed a novel self-similar honeycomb structure and aimed to explore the potential application of additive manufacturing metal honeycomb in protection. Selective laser melting was used to prepare titanium-alloy honeycomb samples. Experiments on compression mechanics were performed in a single-axis plane. A periodic crushing and unloading phenomenon occurred in the platform section. The structural deformation mode and fracture failure mechanism were analyzed by combining a digital camera and a scanning electron microscope. The influence law of wall thickness on the crush unloading of honeycomb was studied based on parameterized finite element numerical analysis. When the self-similar honeycomb of titanium alloys was suffered from in-plane compression, the fracture of the honeycomb edge joint in the structural shear zone area caused periodical crush unloading of the structural stress–strain curve. Obvious tough dimples were observed at the fracture of the failure site, showing obvious plastic-failure morphology. Proper wall thickness thinning increased the rotation angle of the honeycomb’s short side during failure and reduced the minimum bending radius. Besides, it improved crush unloading as well as the bearing stability of the structure. When the relative density was 0.23 (with the wall thickness of 0.11 mm), self-similar honeycomb had optimal structural stability and the highest crush loading efficiency.