Research on metal foams has demonstrated the potential of porous metals to enhance mechanical characteristics, such as energy dissipation, buckling mitigation, and bending rigidity (especially for sandwich panels). The random pore structure of metallic foams is contrasted with micro-architected materials, which have been introduced as highly efficient materials with increased promise in multifunctional applications due to their controlled pore structure.
Vibrations that occur within high speed rotary devices, such as turbines, can lead to excessive wear and fatigue, and measures to reduce vibrations within these components hold significant interest. Dissipation of vibrational kinetic energy under dynamic loading is essential for the attenuation of unwanted vibrations and oscillations that can lead to premature failure. Although polymeric materials typically offer excellent damping properties, they are not feasible in high temperature environments and there is a need for non-polymeric materials that can dampen vibrations at high operating temperatures without the use of a damping fluid.
Randomly oriented, metallic wire mesh dampers were initially developed for use in the space shuttle main engine high-pressure fuel turbo pump. The rotodynamic instability of the rocket engine turbopump, characterized by large and damaging subsynchronous whirling motions, was mitigated with a wire mesh mechanical damper that offered improved stability by reducing the reaction forces on the supports. More recently, General Electric (GE) developed oil-free dampers for applications in turbomachinery. A knitted mesh of interlocking loops of copper wires was compressed into a toroidal shape with 25% mesh density and employed as a bearing support damper that depended on the excitation frequency. However, these mesh solutions were randomly formed and therefore not engineered for optimal damping.
It would therefore be advantageous to provide a custom designed mesh for providing increased damping properties, including (but not limited to) increased damping in a high temperature environment.