PSI - Issue 64

Luca Belluomo et al. / Procedia Structural Integrity 64 (2024) 2197–2205 Author name / Structural Integrity Procedia 00 (2019) 000 – 000

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of the fragment has been assigned and distributed onto the clamps faces that are in contact with the fragment, and as optimization objective the mass has been minimized with a safety factor, at least equal to 2, considering ABS as the material to be used. Non constrained and additive manufacturing methods are considered during the generative design process, made in Autodesk Fusion, obtaining a set of possible variants also concerning different orientations of layers in AM. 3. Case studies 3.1. Exhibition case An exhibition case has been modeled and used in the CAD and Virtual environment, by measuring one of the exhibitional cases present in the MCAC. It is a simple structure made in aluminium, with tempered glass panels for covering. Outer dimensions are 1000mm x 1000mm for a total height of 1800mm, with two horizontal panels useful as basements, one at 850mm and the other at 1350mm from the floor, respectively. These last two values represent the possible values for h b . By tests with the real case and the developed virtual environment, it has been assessed that a standard user (about 1,75 m tall) should stay about 800-1000mm far from a medium object (like the considered case studies in terms of dimensions) in the case in order to see it correctly. It means that the value for D u is chosen to be 900mm in our studies, and that the value for H u is estimated to be 1650mm (Fig. 2(b)).

Fig. 2. (a) Virtual model of the exhibitional case; (b) the chosen positioning for user and objects.

In order to test the procedure, the two test cases, described in the following, will be placed at the two different levels available in the exhibitional case (one at 850mm, the other at 1350mm from the floor respectively). The first retrieval (Bronze Axe) is placed in the first panel (h b = 850mm), and its center of mass is at h cm = 150mm. The second retrieval (Aryballos) has h b = 1350mm and h cm = 80mm.

Fig. 3. (a) Bronze winged axe; (b) Aryballos (unguentary vase).