Magnetostrictive Particulate Composites for Damping

Abstract

Abstract : The objective of this research effort was to develop a new passive smart damping material applicable to a wide range of aerospace structures. We believe that this innovative damping technology is defining a new standard for the field based primarily on the research conducted under this grant. The novel damping approach absorbs energy using domain wall/detwinning concepts dependent upon stress amplitude and independent of vibrational frequency. This new approach was dramatically different than either viscoelastic materials that are frequency dependent and thermally limited or active approaches that require power supplies and external control electronics. As shown in Figure 1 (from Brodt and Lakes) the new materials investigated at UCLA had both large stiffness and large tan delta unlike traditional materials that either had high stiffness with low tan delta (e.g metals or graphite epoxy composites) or low stiffness with high tan delta (e.g. elastomers). The research conducted under this grant helped the scientific community understand some basic physical properties of a wide range of materials under varying thermal-mechanical-magnetic-electrical loading conditions. This research effort was designed to develop a fundamental understanding for these new smart materials.