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SEM image of JSC-2A particles.

SEM image of JSC-2A particles.

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Additive manufacturing (AM) is one of the most promising techniques for on-site manufacturing on extraterrestrial bodies. In this investigation, layerwise solar sintering under ambient and vacuum conditions targeting lunar exploration and a moon base was studied. A solar simulator was used in order to enable AM of interlockable building elements ou...

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... Space Administration (NASA) using mined volcanic sediments in Arizona. JSC-1A used to be supplied by Orbital Technologies Corporation (ORBITEC); however, it is not commercially available anymore. Therefore, JSC-2A material was chosen as the test material for solar sintering investigations in this study. SEM image of JSC-2A simulant is shown in Fig. 1. It can be seen that the particles have irregular shapes and a polydisperse grain size distribution ranging from a few micrometers to 1 mm. For the experiments, JSC-2A simulant was used as received with no additional sieving ...
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... results from ambient and vacuum solar sintered samples are shown Fig. 10. SEM back-scattered images of additive manufactured parts under different working atmospheres confirm the foamy structure seen by tomography analysis of vacuum sintered parts. SEM of the samples revealed the structure formation was due to outgassing of the material trapped between the partially molten grains, thus creating numerous ...
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... analyzed. The geometry of the structures was derived using the hanging model approach. The sintered regolith bricks and the contact conditions between the bricks were structurally idealized as beam elements. The connections between the bricks were modeled as compression only elements in order to allow for gaps opening due to external loads. Fig. 11 shows the beam elements that idealize the bricks; on the left side the connection elements are shown. The rectangles associated to each element indicate tension or compression. Fig. 11 shows that there are no tensile contact forces under dead weight and moonquake in the final structure. Except for two elements near the supports also ...
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... idealized as beam elements. The connections between the bricks were modeled as compression only elements in order to allow for gaps opening due to external loads. Fig. 11 shows the beam elements that idealize the bricks; on the left side the connection elements are shown. The rectangles associated to each element indicate tension or compression. Fig. 11 shows that there are no tensile contact forces under dead weight and moonquake in the final structure. Except for two elements near the supports also the internal brick forces are compression only. This shows that the given geometry can be built from sintered regolith bricks without the use of an additional ...
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... have been sintered, the robots collect the interlocking building elements and position them into the desired building envelope. Depending on the scale of the interlocking element these robots will either be crane type rovers for placing large scale building blocks or paving machine types for placing multiple building blocks in a uniform pattern (Fig. ...
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... nonhomogenous cross section composed of loose sand material embedded and capsuled by a rigid additive manufactured structure would substantially reduce the required manufacturing effort. The required interior additive manufactured structure may be reduced down to 30% of the total volume (Fig. 13). Taking this into account, it would require six printers to build one habitable dome structure per year. Table 4. Density measurements of JSC-2A in powder form and as solar sintered ...
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... bulk density 1.56 Skeletal density 2.92 Ambient solar sintered part density 1.70 Vacuum solar sintered part density 1.21 Fig. 11. Compressive normal forces in final structure with contact elements under tension removed. The stability of the remaining structure proves the viability of assembling structures from element with compression-only ...