A HIGH DAMPING CELLULAR MATERIAL WITH INTEGRATED ARRAYS OF NANOCOMPOSITE WEB-LIKE VIBRATION ABSORBERS
Abstract
Aircraft fuel efficiency and enhanced performance is enabled by advances in lightweight, strong, highly damped multifunctional composites. As new composites with high strength-to-mass ratios are developed, the demand of damping capacity of these lightweight materials will be increasing to ensure safe operations across adverse dynamic conditions. Conventional approaches based on viscoelastic or elastomeric constrained damping are not effective due to poor thermal properties and stiffness/strength mismatch with the hosting matrix. A radically different approach is a cellular material system which incorporates an ultra-light array of miniaturized spider web-like vibration absorbers to damp macro vibrations by transferring kinetic energy from the macro scale into the distributed absorbers at the cellular scale. The miniaturized absorbers are made of webs of electrospun carbon nanotube/polymer wires whose storage and damping capacity can be optimally tuned together with the oscillating mass located at the center of the webs. Tuning the frequency and damping is allowed by the variability in web geometry/thickness and CNT volume fraction regulating the interfacial CNT/polymer stick-slip dissipation. A targeted nonlinear frequency tuning can be sought between the web absorbers and the material wave frequencies over a large range of oscillation amplitudes employing ad hoc reduced-order dynamic models of the cellular material. The power of the proposed cellular material incorporating the ordered array of spider web-like absorbers is that, once optimized, it can exhibit order-of-magnitude damping capacity increments without weight penalty and with intrinsic 2D tunability to maximize kinetic energy transfer in different modes/waves. Such new architectured materials with unprecedented damping capacity can enable new aerospace applications including supersonic/transonic aircraft, in which materials are subject to rapidly growing loads, persistent vibrations, and thermal cycles.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Aug 11, 2021
- Source ID
- FA86552017025
Entities
People
- Walter Lacarbonara
Organizations
- Air Force Office of Scientific Research
- Sapienza University of Rome
- United States Air Force