关键词: 增材制造, 钛合金, 低速冲击, FCC和BCC微桁架结构, 破坏模式

Abstract: Additive manufacturing technology is capable of molding complex lattice structures at one time, overcoming the debond problem at the connection point of the core layer and the surface layer of the traditional technology under low-velocity impact. Low-velocity impact tests were performed on additively manufactured Face-Centered Cube (FCC) sandwich panels and Body-Centered Cube (BCC) sandwich panels respectively, using a drop-weight test device, from which the failure mode and impact curves of the sandwich panels were obtained. The smaller indentation depth on BCC sandwich panels than that on FCC sandwich panels under the same energy impact indicates better impact resistance of BCC than FCC sandwich panels. Under low-velocity impact, a pit and a crack appeared at the impact site on the upper layer of the lattice sandwich. However, no large deformation occurred in the rest of the area. A finite element model was developed to simulate the impact response of lattice sandwich panels. For both panels, the impact energy is mainly absorbed by the upper layer and the sandwich layer, with the energy absorption ratio of each part changing little when the impact energy changes. Thus the overall structure of both BCC and FCC sandwich panels is stable and integral. The damage of the FCC sandwich panel initiates from the connection between the upper layer and the vertical truss, while that of the BCC sandwich panel initiates from the vertical truss.

Key words: additive manufacture, titanium alloy, low-velocity impact, FCC and BCC lattice structures, failure mode