US Patent 9791014 Enhanced damping materials using negative stiffness inserts

In one embodiment, a vibration control apparatus is provided having a pair of face sheets with a core material in between. The core material comprising a positive stiffness material. A stack comprising a positive stiffness structure in series with a negative stiffness structure is located between the pair of face sheets, in parallel with the core material. The stack may be embedded in the core material. Various embodiments may include multiple stacks in parallel with each other. In some embodiments, the stack may include multiple positive stiffness structures in series with multiple negative stiffness structures. The multiple positive stiffness structures and negative stiffness structures may be interleaved.