Temperature-Programmable SMA Absorbers for Vibration Control in Metastructures

In this work, we investigate a shape-memory-alloy (SMA) vibration neutralizer for structural vibration control that can be thermally tuned across target frequencies. The device couples a tuning mass to the host structure through SMA elements whose stiffness varies with temperature via the martensite-austenite phase transformation, enabling adaptive passive tuning without external dynamic actuation. Beyond tunability, we examine the neutralizer’s intrinsic nonlinearity, its amplitude-dependent effective stiffness and damping, which yields curved backbone responses, jump phenomena near resonance, and attenuation that broadens as the excitation level changes. These behaviors can be exploited to expand the bandwidth around the tuned frequency and to improve robustness against detuning. Analytical modeling and laboratory experiments on single and multiple neutralizers confirm temperature-induced frequency shifts and controllable hysteresis. When an array of SMA neutralizers is distributed along a beam, these properties translate into reconfigurable and widened stop-bands that can be repositioned by heat input, providing compact, adaptable vibration suppression with minimal hardware.