Enhanced compressive properties of additively manufactured hollow sphere materials with novel configurations

Abstract

Based on the porous structure of classic simple-cubic hollow sphere (SHS) materials, two novel configurations—simple-cubic perforated hollow sphere (SPHS) and hollow ellipsoidal sphere (SHES) structures were designed by introducing perforations in sphere walls and altering the ellipsoid ratio, defined as the ratio of the major and minor axes of an ellipsoid. Using 316L stainless steel as the raw material, a series of specimens were fabricated employing additive manufacturing technology. Corresponding finite element models were established using Abaqus. Then the experimental and numerical investigations were conducted to analyze the deformation behavior of these structures subjected to quasi-static compression. Further numerical research was conducted to analyze the mechanical properties of multi-cell hollow sphere structures with varied parameters, including wall thickness, perforation diameter, and ellipsoid ratio. The results confirmed that a perforation diameter of 4 mm resulted in optimal performance for the SPHS. In comparison to the basic structure SHS with identical relative density, this configuration exhibited a 60 % higher specific yield strength. Additionally, for SHES, when the ellipsoid ratio exceeded 1 while less than 1.8, the specific yield strength demonstrated a maximum increase of 69 % ∼ 105 % and the maximum enhancement in specific energy absorption was 60 % ∼ 85 %.

Keywords

• Hollow sphere structure
• Lightweight
• Mechanical property
• Energy absorption
• Yield strength