Damping Performance of Glass Fiber Reinforced Polymers With Embedded Shape Memory Alloy Wires

Abstract This paper explores the integration of shape memory alloy (SMA) wires within fiber reinforced polymer (FRP) composites to enhance their dynamic properties. The strategic embedding of these wires is essential for achieving optimized performance characteristics, allowing the SMA wires to effectively respond to external effects such as mechanical loads, vibrations, and environmental changes. Towards this goal, the SMA/glass/epoxy composite laminates were manufactured using a wet lay-up vacuum bagging process, with SMA wires embedded between fabric layers at specified positions through the laminate thickness, ensuring symmetry around the neutral plane. The hybrid SMA-FRP laminates were tested in a cantilever beam configuration to assess their dynamic response. A Scanning Laser Doppler Vibrometer (SLDV) was employed, along with an impact hammer for excitation, to measure the natural frequencies, as well as the vibrational velocity over force of the samples. The dynamic behavior of laminates with different through-thickness placements of SMA wires was compared between their active and inactive cases for each sample. Three mode shapes were observed for all samples, and the mode shapes remained unchanged with SMA wire activation. Activation of the SMA wires resulted in a reduction of the quality factor by up to 50% and a decrease in natural frequencies by 16–21%, demonstrating the significant effect of the embedded wires on enhancing the damping behavior of the laminates. Moreover, laminates with SMA wires embedded between each fabric layer (fabric/wires/fabric/wires/fabric/wires/fabric) demonstrated a stronger damping effect, with mode shapes occurring at lower frequencies compared to laminates with SMA wires embedded in an alternating pattern, with two consecutive fabric layers in the middle (fabric/wires/fabric/fabric/wires/fabric). These advancements hold promise for aerospace structures, where enhanced tunable vibration control and energy absorption are desirable for safety and performance.