Several properties displayed by shape-memory alloys include shape-memory based on a temperature-induced phase transformation, superelasticity based on a stress-induced phase transformation, and excellent fatigue and corrosion resistance that can be exploited individually and in combination to provide both passive and active damping and/or stiffness control for all types of structures. For aerospace structures, in particular, the extremely high specific-energy dissipation on bulk and/or mass and volume basic and the relative insensitivity to temperature variations of some shape-memory alloys enable the design of extremely light and effective damping devices. Device types utilizing this approach include linkage, constrained-layer, and modified-joint devices. This project will develop this promising technology for the damping of aerospace structures by providing materials characterization for all relevant alloys including shape memory, pseudoelasticity, fatigue behavior, temperature sensitivity, internal and hysteretic damping, etc. This will characterize all device types including force deflection hysteresis, reliability, cost, etc., and will demonstrate promising device types for frame structures for a small-scale, shake-table facility.A reliable, cost-effective, precisely controllable damping technology would apply to the design of virtually every type of civil, mechanical, and aerospace structure subject to dynamic loads. For civil structures, this technology promises a solution to seismic and wind problems; for aerospace structures, a new design modality for blast, impact, and cyclic loading; for conventional mechanical devices, a significant reduction in acoustical and structural vibrations.superelasticity, shape-memory, damping, passive devices, active devices, hysteresisSTATUS: Phase I Only
