Issue 40

M. Mentzini, Frattura ed Integrità Strutturale, 40 (2017) 95-107; DOI: 10.3221/IGF-ESIS.40.09 104 required. On the lower side of the drum the reinforcement was inserted from outside, from areas of the drum’s view, which appeared marks of decay, loosing their original ancient surface (Fig.18 right). 4. Finally, the join of the supplement to the ancient marble to fill the loss “D 1 F 1 ” was accomplished by inserting titanium bars both on the upper and on the lower side of the drum through the fractured area with direction parallel to the member’s upper side (Fig.19 left). This reinforcement is the proper one to avoid overturning of the supplement, before the overturning of the drum as a whole. In order to achieve the proper anchorage length of the reinforcement on the supplement’s lower area, because of the thin thickness of the new volume there, the end of these bars has also been specially threaded to fit a screw nut through a titanium plate anchor (Fig.19 right). Figure 16 : Sketch of the failures of the drum (Drawing: M. Mentzini, YSMA Archive). Figure 17 : Adjusting a new marble (supplement “DF”) onto the upper side of the drum (left). Near by, the reinforcement required to restore the fragment “ΔFF 1 ” is presented (ellipse in the left figure). Drawing of the parts to be joined together and their geometry for the calculation of the stress field and consequently the reinforcement required (right) (Drawing: M. Mentzini, YSMA Archive). Figure 18 : After joining the supplement “DF” to the main volume of the drum, the holes (in order to adjust the titanium plate anchor) on its surface sealed with the pieces of the extruded new marble (on the left). Repairing the crack “df 2 ” (on the right).