Quasi-Static Four-Point Bend Testing of Macro-Fiber Composite Unimorphs

Abstract

This research examines the application of Macro-Fiber Composites on substrate materials in the form of unimorph actuators. The intent is to characterize the behavior of the unimorphs and to gain an understanding of the load bearing capacity as a function of the substrate. The results indicate that thin substrates, on the order of 0.1 mm, with a high modulus, on the order of 200 GPa or more, provide the largest displacements and load bearing capacity. Both classical laminate plate theory and experimental results are used to support this conclusion. The experimental tests used a four point bend setup to load the unimorphs through their entire range of deflection and quantified their load bearing capacity throughout this range. These results were compared to Classical Laminate Plate Theory, in terms of loading and curvature, with good agreement. The primary application of this research is for use on small unmanned vehicles, but these results can be expanded to other Macro-Fiber Composite applications as well.