Design and Realization of a Novel Elastomer Characterization System for Precision Positioning Application

Elastomeric bearings have been used in seismic engineering and precision design recently. With their nature in stiffness anisotropy, they could possibly achieve the similar function as compliance mechanisms and this represents an advantage in compact precision design. However, the mechanical behaviors of elastomers are relatively complicated and must be carefully evaluated and there are actually no adequate characterization systems well fit for such requirements for precision engineering. As a result, in this work, a novel biaxial testing system is realized by integrating a voice coil actuator, a capacitive probe, a load cell, a rotating stage, and a wiimote camera based angular sensor, under a simple temperature controlled environment. A 100 Hz bandwidth can then be achieved. Essential structural compliance due to finite structure loop stiffness has been pre-characterized and compensated. This system is then validated by comparing the PDMS punch test results with the previous reported data. After being validated, this system is then applied on PDMS and RTV3310 rubbers for investigating their essential mechanical properties and structural longevity. To understand the rubber bearing properties, three experiments have been conducted: compression, shearing, and fatigue tests. In summary, the biaxial material testing system has been realized and has been taken for performing necessary material experiments to achieve result for guiding rubber bearing designs used in precision engineering.