No abstract

The printing accuracy is one of the key factors affecting the final additively manufactured structures. As metamaterials for wave controlling, the printing accuracy caused in additive manufacturing can affect the band gap structures and the wave transmissions in phononic crystals (PnCs). Selective laser melting (SLM) was used to fabricate the designed PnCs. AlSi10Mg was used as the material for the fabrication. The distorted geometry of the additively manufactured PnCs by selective laser melting (SLM) was experimentally measured and then was re-built as finite element model. The band gap structures and the wave transmissions were calculated based on finite element method for the comparison of the structural performances of the theoretically designed and fabricated PnCs. Result indicated that the fabricated PnCs were thermally distorted from 0.298 mm to 1.664 mm depending on the designed geometries. The thermal distortion can lead to a deviation of central frequency in the range of -6.2%~3.7% in comparison with the theoretical design. Compared with the theoretical design, the band gap widths of the distorted PnCs vary from -7.4% to 5.6% due to the frequencies change of the eigenmodes at the upper and lower band edges which are directly affected by the thermal distortion. The further analysis shows that the change of the band structures of the distorted PnCs is due to the increase of the inertia moment of the distorted PnCs caused by the printing accuracy.