Multi-scale contact mechanics framework for upper palaeolithic ground stone tools

This work presents a multi-scale and multi-resolution digital twin model of Upper Paleolithic ground stone tools (GSTs) to simulate their tribological evolutions. The physics-based digital twin relies on a multi-scale dataset of a passive tool used in a replicative experiment, incorporating the stone macroscale 3D reconstruction and the profilometric microscale surface map. The computational model, simulating a vertical pounding action, allows the prediction of the pressure distributions and the real contact area, where surface modifications due to contact are prone to appear. It is based on the Boundary Elements Method for solving the contact problem at different scales, using the photogrammetric reconstruction of the stone surface at the macroscale and the 3D confocal scanning at the microscale. This unprecedented digital twin model links macroscale to microscale contact mechanics simulations and is validated against experimental replicas, comparing the prediction with the wear patterns observed on the passive tool's surface.