Two-mode tuned vibration absorber

A dual-frequency vibration-reduction apparatus, comprising:

• a first beam having a longitudinal axis and a transverse axis perpendicular to the longitudinal axis;
• an attachment mechanism for mechanically coupling a portion of the first beam to a structure;
• a second beam and a third beam attached to the first beam such that the dual-frequency vibration-reduction apparatus vibrates bi-modally at a first frequency and a second frequency for reducing vibrations of the structure at the first frequency and the second frequency,
• wherein the second beam and the third beam are adjustably attached to the first beam for adjusting a position along the longitudinal axis, thereby enabling the dual-frequency vibration-reduction apparatus to be tuned for attenuating a variety of frequency vibrations.

A tuned vibration absorber for attenuating a primary frequency vibration of a structure and a secondary frequency vibration of the structure, comprising:

• a first beam having an attachment bracket for attaching the first beam to the structure;
• a second beam adjustably attached at a first end portion of the first beam, the second beam having a first mass and a second mass adjustably attached at opposite ends of the second beam;
• and
• a third beam adjustably attached at a second end portion of the first beam, the second end portion being opposite the first end portion, the third beam having a third mass and a fourth mass adjustably attached at opposite ends of the third beam,
• wherein the second beam and the third beam are positioned about the first beam to provide a bending mode vibration of the first beam for attenuating a vibration of the structure at a primary frequency.