Robotically controlled scale-model testing of masonry vault collapse

Scale-model testing can be used to understand the equilibrium and validate the computational modelling of discrete-element assemblies subjected to external loads or support displacements. This paper proposes a novel approach to investigate the collapse of discrete-element assemblies using 3D-printed scale models manipulated with force-sensitive robotic arms combined with an optical measuring system. To demonstrate that this provides a more flexible and comprehensive solution for the assessment of the structural behaviour of unreinforced masonry structures, the same setup is used to conduct different types of experiments on a 3D-printed model of a cross vault. First, the robotic arms are used to apply a point load in different locations while measuring the resistance of the vault until collapse. In a second experiment, the robotic arms are used to simulate the effect of progressive differential settlement of the supports of the vault. The trajectory along which the displacement of the support is applied is based on real-time measurements by the force-sensitive robots of the occurring outward thrust.