Experimental and numerical studies on compressive mechanical properties of hollow-sphere structures with perforations

Large Deformation and Energy Absorption Behaviour of Perforated Hollow Sphere Structures under Quasi-Static Compression

“…Figure 2a-c shows the 3D printed 3 × 3 × 3-cell PHSSs in different arrangements, where R m = 9.75 mm, d = 20.5 mm, d m = 5.5 mm, and t = 0.5 mm, and the relative density is 0.0654, 0.0833, and 0.0882, respectively. The relative density can be calculated by Equation (1) [25].…”

“…Additive manufacturing/3D printing, as an emerging manufacturing technology, can be used to directly produce more complex components regardless of the structure or shape, and this technique offers a new approach for fabricating hollow sphere materials. Recently, researchers have used stainless steel, photosensitive resin, polylactic acid (PLA) plastics, and nylon to fabricate different hollow sphere structures through additive manufacturing techniques, such as fusion selective laser melting (SLM) [23,24], stereolithography (SLA) [25], fused deposition modelling (FDM) [26], and multi-jet fusion (MJF) [27], and carried out a series of experiments to investigate the mechanical properties of these structures, most of which introduced perforations or open porosities in spherical walls to remove the excess material inside the structure during post-processing of 3D printing; however, these perforations in hollow spheres change the physical and mechanical properties of hollow sphere structures to some degree. Parameter studies have also been conducted by using finite element models (FEMs) to quantitatively analyse the effect of geometric parameters on the structural mechanical properties [25,27].…”

Numerical investigations on the mechanical properties of metallic hollow spheres structure with perforations under compression

“…Thanks to their perforation design, this kind of hollow spheres can be perfectly produced with three dimensional printing technology. However, for traditional hollow spheres, it is impossible to take out the redundant metal powder or supporting material from them in three dimensional printing [21].…”

“…Thus, by combing with symmetric boundary conditions, the 5 × 5 cells models, which were proved to be realistic situation representations, were established by the software ABAQUS 6.14 for calculation in this work [13], Figure 3. Regular hexahedron element (C3D8R) meshes with sufficient refinement could be employed to achieve a more accurate simulation [11,21].…”