Mechanical performance and defect analysis of the imperfect micro smooth gyroid cylinder shell structure

Projection micro-stereolithography (PμSL) technique has been demonstrated effective in fabricating the micro lattices. However, the complex fabrication process would inevitably yield stochastic geometric defects within the target structure. In this paper, compressive mechanical properties and deformation modes of the micro gyroid cylinder shell structure with defects originated from the PμSL process were examined through experimental test and numerical simulation. Both the synchrotron X-ray tomography (SR-μCT) investigation and interrupted in-situ compression experiment were conducted to study the role of process-induced defects on the mechanical behavior. Testing results indicated that the fabricated thickness value was much larger than the design value, which had a non-negligible effect on the mechanical properties of the gyroid cylinder shell structure. Then, the reconstructed 3D true model was proposed based on the 2D tomography images. Simulation results indicated that the true model predicted results were more consistent with the experimental results when compared with the ideal model.