A Preliminary Investigation of Wave Propagation in Beam-Like In-Vacuo Tunable Structured Fabrics

Structured fabrics, such as traditional knitted sheets or chain mail armours, exhibit low bending stiffness under ambient pressure. However, recent studies have demonstrated that applying a modest confinement pressure (approximately 90 kPa) can increase their stiffness by more than 25 times. This enhancement facilitates the development of lightweight, tunable, and adaptive materials for applications in wearable exoskeletons, haptic systems, and vibration control devices, including tunable vibration absorbers. This work investigates a chain mail fabric composed of three-dimensional, rigid, truss-like elements fabricated via material deposition techniques. The structures are enclosed in a vacuum bag, inducing jamming through interlocking and friction among adjacent particles, which results in a solid-like state. Experimental dispersion curves under varying confinement pressures are presented, revealing bending-dominated wave modes at low frequencies. Furthermore, a preliminary numerical model developed to replicate the experimental results is introduced.