Investigation on Mechanical Properties, Damage Forms, and Failure Mechanisms of Additively Manufactured Schoen Gyroid TPMS Porous Structures Under Compressive Load

To address the conflicting demands of lightweight materials and high load-bearing capacity in high-end fields such as aerospace and biomedical engineering, there is an urgent need to conduct research on the mechanical behavior and response mechanism of porous titanium alloy structures. In this paper, a combination of experimental testing, numerical simulation, and theoretical analysis was employed to conduct the research. A titanium alloy porous structure with different porosities was constructed based on classical three-period minimal surface optimization, and its preparation was completed using advanced selective laser melting technology. A multidimensional characterization experimental device was established to accurately obtain its mechanical performance data. It was found that the mechanical behavior of the structures is insensitive to loading rates, but more sensitive to their structural volume fraction. The quantitative characterization of microstructure damage and fracture morphology, as well as the identification of failure modes, indicates that the microstructure damage of the porous metal exhibits a ductile-brittle synergistic damage characteristic. By combining high-precision numerical simulation technology, the damage modes and damage evolution laws of porous metal structures in titanium alloys were comprehensively elucidated. By analyzing energy dissipation and constructing evaluation indicators for energy absorption efficiency, the energy absorption characteristics of the porous metal structure were elucidated, and the interaction behavior and correlation mode between the platform stress and the structural volume fraction of the porous metal structure were accurately described.