Design of Experiments of the Elastomer test rig

In this brief report is described the experimental characterization of the elastomer used for the suspension of the robotic electrospindle. The characterization consists in the evaluation of the elastomer properties (i.e. dynamic stiffness, loss factor for various frequency/temperatures) thanks to a shear test of two elastomer disk. Where possible the characterization adopts similar arrangement of the electrospindle suspension (e.g. size of disks, frequency of interest, loads magnitude and direction, materials). The test rig is built in STIIMA-CNR and use few configurations: 1) Direct measurement: the elastomer sample is attached to one hand to the ground (where the applied force is measured) and on the other hands is attached to the external excitation (shaker). The relative displacement of the sample is measured and then the dynamic stiffness is calculated. 2) Base Excitation Resonance Mass (BERM): the elastomer sample is attached on one hand to an enforced DOF (in our case the shaker head) and on the other side is attached to a free DOF with a suspended mass. The system appears like a traditional problem of a foundation used to mitigate the vibrations coming from the environment. 3) Static test