PSI - Issue 34

Guilherme Guimarães et al. / Procedia Structural Integrity 34 (2021) 26–31 Guilherme Guimarães/ Structural Integrity Procedia 00 (2021) 000 – 000

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After the manufacturing, the samples were submitted to a stress relief treatment, being hold at 650°C for 60 minutes and then air-cooled. The samples were removed from the base plate with 32 TPI bi-metal HSS Starrett blade. After the removal the samples were submitted to a surface grinding procedure, to guarantee parallelism between the face the will be subjected to the compressive load. The lattice characterization was carried out by uniaxial compression testing using an INSTRON 5969 universal testing machine with a 30 kN load cell. The loading deformation rate was calculated using the ASTM E9 procedure, being defined at 0.025 mm/s with the stopping point define at 10%. The deformation was calculated using the linear displacement from the head. The equivalent stress was calculated using the force data from the loading cell applied to the effective area of the sample. Since the area will vary with the depth due to the gyroid structure, several cuts were performed on the 3D model, and a smaller area was used. Figure 4 exemplifies the procedure.

Figure 4: Determining the section area to calculate the stress

3. Results When analyzing the weight reduction it can be observed that the gyroid was effective in reducing the overall weight. By comparing the lattice with the solid body it was observed a reduction of 60% in mass. Figure 5 shows the reduction achieved for each cell size.

Figure 5: Lattice weight reduction