The integration of 3D technologies and finite element analysis (FEA) for the restoration of an ancient terra sigillata plate

Abstract

The current study presents a novel approach for restoring a partly preserved archaeological find with the combination of 3D scanning, 3D printing and Finite Element Analysis (FEA). The aim is twofold: a) to restore the ancient artifact with minimal human intervention and handling, and b) to attest that the materials used in the restoration process produce an ancient artifact of robust assembly. The object under investigation is a two-handled terra sigillata plate unearthed in two fragments that amount to less than 50% of the original artifact's geometry (i.e., volume, and shape). The methodology used followed a systematic process. First, the replication of the physical object inside a digital environment to acquire a high precision digital copy of the plate using structured-light 3D scanning technology and the creation of a digital model of the missing part of the original plate following a specific mirroring technique. The two models were assembled into one complete, digital 3D model that depicts the restored ancient plate. Next, the physicochemical properties of the clay used in the manufacture of the original plate were obtained using Energy Dispersive X-Ray analysis (EDX) and Scanning electron microscopy (SEM). The same analytical techniques were also implemented in order to acquire the mechanical properties of the PLA polymer used for the manufacturing of the reconstructed part of the plate. The acquired properties were used as input for the simulation of the assembled model's structural behaviour under bending loading by means of Finite Element Analysis (FEA). The behaviour of both the original ancient ceramic and the PLA polymer are predicted to secure the structural integrity of the digitally restored plate. Having established that the choice of materials satisfies the aim of a robust restored ceramic vessel, a physical copy of the missing part with the use of 3D printing technology was manufactured. Finally, the restoration of the original archaeological artifact was implemented by assembling its partly preserved piece and the 3D printed missing part into a complete artifact with traditional restoration techniques.