An inertial mass amplification type tuned mass damper is disclosed. The inertial mass amplification type tuned mass damper comprises a hollow box, an H-shaped mass block, gears a, gears b, a rectangular frame, a steel ring, viscous dampers, a steel sheet, springs, rotating shafts and balls. In the present invention, an inertial damping force is amplified by adjusting the radius ratio of the gears a and the gears b; and damping parameters can be conveniently changed by adjusting the mass of the mass block, the spring stiffness and the like. The present invention has the advantages that the design mass is small, which can avoid the adverse effects of excessive additional gravity on the structure and improve the performance of the structure. The present invention has reasonable design and small occupied space, can save more use area for buildings and can greatly improve the utilization efficiency of the buildings.

In a boiler support structure in which certain ones of seismic isolators are provided with a pullout countermeasure, the seismic isolators to be provided with the pullout countermeasure are individually identified according to whether the seismic isolator satisfies Formula (1) : N.sub.Dn+N.sub.EQn>N.sub.tn . . . Formula (1) , where N.sub.Dn (N.sub.D<0) is a compressive load occurring on each of the seismic isolators and calculated on the basis of a permanent load imposed on the boiler support structure; N.sub.EQn (N.sub.EQn>0) is a pullout force occurring on each of the seismic isolators and calculated on the assumption that an earthquake has occurred; and N.sub.tn (N.sub.tn>0) is an allowable pullout force of each of the seismic isolators and calculated using an allowable pullout stress of each of the seismic isolators.

A novel impulse damper for reducing extreme vibrational events, in particular, in tall, narrow structures such as wind turbines. The impulse damper, according to the invention, operates on the impact-damping principle and is particularly suitable for damping the second natural frequency of the installation, preferably of the tower of a wind turbine.

The present invention refers to a mass damper for reducing vibrations of a structure with a pendulum mass and a damping means, wherein the mass damper has at least three bearings with which the pendulum mass is movably supported on the structure such that it can execute pendulum movements and each of the bearings has at least one pendulum plate with a concave bearing surface and a sliding shoe arranged movably thereon with a convex counter surface. In accordance with the invention, the bearing surfaces and the associated counter surfaces are curved with a constant radius of curvature R and all bearings have a lowest possible friction between the counter surface and the bearing surface. The invention also extends to a structure with such a mass damper and a method for adjusting the natural frequency of a mass damper, in which the natural frequency of the pendulum mass can be adjusted independently of one another in both main directions by displacing and/or rotating the pendulum plates. The invention also extends to the damping means, which can be implemented with linear viscous passive damping, with square viscous passive damping or with controlled damping, in order to tune this damping together with the friction damping of the bearings to the optimum damping of the mass damper.

A pendulum mass damper is directed to damping oscillation of tall buildings, towers or similar flexible structures requiring a low frequency tuned mass damper (TMD) for reducing a e.g. wind or earthquake induced displacement response of the structure. A mass (1) is balanced by a first spring system (2a, 2b, 2c) and supported by a carrying part (4) to maintain a vertical position, the carrying part (4) carrying the mass in the vertical direction extends between the mass and a position (C) below the mass, i.e. the weight of the mass is carried or supported from or at a point or level below the mass, wherein the mass at the position (C) below the mass is fixed and/or connected to a unit (5) constituting a base of a supporting system for the mass which unit is floating i.e. the unit can move either horizontally or both horizontally and vertically.

The dynamic vibration damping system for a building, comprises damping units inserted in housings located in the building façades, or slabs, or partition walls. The damping units comprise a swinging mass (2) sliding horizontally in opposite directions on a swinging plane parallel to the façade or to the slab or to the partition wall when the building vibrates, horizontal springs (3) to absorb the energy generated by the movements of the swinging mass (2), and dampers (4) to damp movements of the swinging mass (2).

A function-recovering energy-dissipating reinforced concrete shear wall comprising a reinforced concrete shear wall body, common steel bars distributed in vertical direction within the reinforced concrete shear wall body, common steel bars distributed in horizontal direction within the reinforced concrete shear wall body, high-strength reinforcing materials arranged on left and right sides of the shear wall, and four dampers arranged in an X-shaped cross mode between a front reinforcement fabric and a rear reinforcement fabric that are formed by common steel bars distributed in vertical direction and common steel bars distributed in horizontal direction; a cylindrical piston rod having a hinge hole is arranged at the end portion of each damper.

A system for damping vibration of a tower structure at a selected one or more natural frequencies of the tower structure. The system includes a tank assembly with one or more tanks, and a fluid positioned in the tank to a preselected depth above a floor. The tank includes wall(s) defining an average travelling distance of a wave through the fluid initiated by the vibration of the tower structure at the natural frequency. The system includes one or more inserts located on the floor in the tank for damping movement of the fluid. The preselected depth and the average travelling distance are selected so that the fluid is movable at the selected natural frequency and out of phase with the vibration of the tower structure, to dampen the vibration of the tower structure at the selected natural frequency.

The present disclosure relates to a damping system for counteracting oscillations in a construction. The damping system comprises a pendulum device and a container which contains a viscous medium. The pendulum device comprises a mass which comprises a porous structure. The porous structure is configured to allow the viscous medium to pass through it. The porous structure is at least partially submerged in the viscous medium.

Precast construction elements are described suitable for use in high seismic areas. The precast construction elements can be precast, pre-topped double tees. The precast construction elements incorporate a passive energy dissipation device in a flange. The energy dissipation device provides a ductile connection having a deformation capacity of larger than 0.6″. Adjacent elements are connected to one another at joints that include the passive energy dissipation device. Passive energy dissipation devices can be passive hysteretic dampeners, such as U-shaped flexural plates. Passive energy dissipation devices can be bar dissipaters (e.g., grooved dissipaters). Also described are passive hysteretic dampers that include U-shaped flexural plates held in conjunction with a reinforcement element that defines a circle around which the flexural plate can bend.