Quasi-static compressive behaviors of large-size titanium lattice sandwich structure based on pulse hot-wire arc additive manufacturing

Abstract

Large-size lattice sandwich structure (LSS) has broad application prospects in the industrial field because of its specific stiffness and high strength. Quasi-static compression behavior is one of the basic mechanical properties of LSS. In this paper, large size titanium pyramid lattice sandwich structures were fabricated by pulse hot-wire arc additive manufacturing (PHWAAM). The mechanical properties and failure modes of pyramid LSS were studied by quasi-static axial compression tests. Theoretical and experimental analyses showed that the compression strength of 4-cells LSS differs greatly from that of 5-cells LSS, and the specific strength and specific stiffness also differ significantly. 5-cells LSS has better compression behavior, strength is 608.23 MPa higher than the 4-cells LSS. The process of lattice damage during the experiment was observed, and the failure mode was analyzed by theoretical calculation together with metallography and fracture. The main failure mode is brittle fracture, but there is plastic deformation in some lattice cells. The compression properties of the two kinds of LSS are studied by finite element method (FEM) and compared with the theoretical and experimental results. The research findings presented in this study provide a concise and effective guidance for quasi-static compressive behaviors of large-size LSS. The proposed conclusion is of great significance to the explore of the mechanical properties of LSS manufactured by WAAM.