Damper

A damper for damping vibrations of a structure, comprising:

• a first damping unit, comprising a first damping body having a first mass (m1), a first spring element having a first spring constant (k1) and a first damping element having a first damping constant (c1), wherein said first damping body is configured to be attached to said structure via said first spring element and said first damping element;
• and
• a second damping unit, comprising a second damping body having a second mass (m2), a second spring element having a second spring constant (k2) and a second damping element having a second damping constant (c2);
• wherein said second damping body is configured to be attached to said first damping body via said second spring element and said second damping element;
• wherein
• m0 is the mass of said structure;
• µ
• =
• (
• m
• 1
• +
• m
• 2
• )
• /
• m
• 0
• ;
• ω
• 0
• =
• √
• k
• 1
• m
• 1
• ;
• ω
• 2
• =
• √
• k
• 2
• m
• 2
• ;
• Ω
• 2
• =
• ω
• 2
• /
• ω
• 0
• ;
• wherein 0.018≤μ≤0.25;
• and
• wherein Ω2 is selected such that an estimate d*e of an ensemble radius of the damper defined by
• d
• e
• *
• (
• μ
• ,
• Ω
• 2
• )
• =
• 1
• -
• (
• 9
• 2
• ⁢
• μ
• ⁡
• (
• 1
• +
• μ
• )
• 5
• /
• 2
• ⁢
• Ω
• 2
• 4
• (
• 1
• -
• Ω
• 2
• 2
• )
• 3
• /
• 2
• ⁢
• 3
• +
• 6
• ⁢
• Ω
• 2
• -
• 1
• +
• Ω
• 2
• 2
• -
• 2
• ⁢
• Ω
• 2
• 4
• )
• 1
• /
• 4
• fulfills the relation d*e>0.375.