US20180002923A1 - Adjustable stiffness assembly - Google Patents

Adjustable stiffness assembly Download PDF

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Publication number
US20180002923A1
US20180002923A1 US15/638,882 US201715638882A US2018002923A1 US 20180002923 A1 US20180002923 A1 US 20180002923A1 US 201715638882 A US201715638882 A US 201715638882A US 2018002923 A1 US2018002923 A1 US 2018002923A1
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Prior art keywords
stiffness
mount
mass
rotatable
assembly
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US15/638,882
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English (en)
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John Craven Swallow
Allan Leo Raun
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John Swallow Associates Ltd
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John Swallow Associates Ltd
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Assigned to JOHN SWALLOW ASSOCIATES LIMITED reassignment JOHN SWALLOW ASSOCIATES LIMITED ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: RAUN, ALLAN LEO, SWALLOW, JOHN CRAVEN
Publication of US20180002923A1 publication Critical patent/US20180002923A1/en
Priority to US16/558,456 priority Critical patent/US11753819B2/en
Abandoned legal-status Critical Current

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    • E—FIXED CONSTRUCTIONS
    • E04—BUILDING
    • E04B—GENERAL BUILDING CONSTRUCTIONS; WALLS, e.g. PARTITIONS; ROOFS; FLOORS; CEILINGS; INSULATION OR OTHER PROTECTION OF BUILDINGS
    • E04B1/00—Constructions in general; Structures which are not restricted either to walls, e.g. partitions, or floors or ceilings or roofs
    • E04B1/62—Insulation or other protection; Elements or use of specified material therefor
    • E04B1/92—Protection against other undesired influences or dangers
    • E04B1/98—Protection against other undesired influences or dangers against vibrations or shocks; against mechanical destruction, e.g. by air-raids
    • E—FIXED CONSTRUCTIONS
    • E04—BUILDING
    • E04H—BUILDINGS OR LIKE STRUCTURES FOR PARTICULAR PURPOSES; SWIMMING OR SPLASH BATHS OR POOLS; MASTS; FENCING; TENTS OR CANOPIES, IN GENERAL
    • E04H9/00—Buildings, groups of buildings or shelters adapted to withstand or provide protection against abnormal external influences, e.g. war-like action, earthquake or extreme climate
    • E04H9/02—Buildings, groups of buildings or shelters adapted to withstand or provide protection against abnormal external influences, e.g. war-like action, earthquake or extreme climate withstanding earthquake or sinking of ground
    • E04H9/021—Bearing, supporting or connecting constructions specially adapted for such buildings
    • E04H9/0215—Bearing, supporting or connecting constructions specially adapted for such buildings involving active or passive dynamic mass damping systems
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16F—SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
    • F16F7/00—Vibration-dampers; Shock-absorbers
    • F16F7/02—Vibration-dampers; Shock-absorbers with relatively-rotatable friction surfaces that are pressed together
    • F16F7/023—Vibration-dampers; Shock-absorbers with relatively-rotatable friction surfaces that are pressed together and characterised by damping force adjustment means
    • F16F7/026—Vibration-dampers; Shock-absorbers with relatively-rotatable friction surfaces that are pressed together and characterised by damping force adjustment means resulting in the damping effects being different according to direction of rotation
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16F—SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
    • F16F7/00—Vibration-dampers; Shock-absorbers
    • F16F7/02—Vibration-dampers; Shock-absorbers with relatively-rotatable friction surfaces that are pressed together
    • F16F7/06—Vibration-dampers; Shock-absorbers with relatively-rotatable friction surfaces that are pressed together in a direction perpendicular or inclined to the axis of rotation
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16F—SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
    • F16F7/00—Vibration-dampers; Shock-absorbers
    • F16F7/10—Vibration-dampers; Shock-absorbers using inertia effect
    • F16F7/1028—Vibration-dampers; Shock-absorbers using inertia effect the inertia-producing means being a constituent part of the system which is to be damped
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16F—SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
    • F16F7/00—Vibration-dampers; Shock-absorbers
    • F16F7/10—Vibration-dampers; Shock-absorbers using inertia effect
    • F16F7/104—Vibration-dampers; Shock-absorbers using inertia effect the inertia member being resiliently mounted
    • F16F7/116—Vibration-dampers; Shock-absorbers using inertia effect the inertia member being resiliently mounted on metal springs
    • E—FIXED CONSTRUCTIONS
    • E04—BUILDING
    • E04B—GENERAL BUILDING CONSTRUCTIONS; WALLS, e.g. PARTITIONS; ROOFS; FLOORS; CEILINGS; INSULATION OR OTHER PROTECTION OF BUILDINGS
    • E04B1/00—Constructions in general; Structures which are not restricted either to walls, e.g. partitions, or floors or ceilings or roofs
    • E04B1/18—Structures comprising elongated load-supporting parts, e.g. columns, girders, skeletons
    • E04B1/19—Three-dimensional framework structures
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16F—SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
    • F16F13/00—Units comprising springs of the non-fluid type as well as vibration-dampers, shock-absorbers, or fluid springs
    • F16F13/005—Units comprising springs of the non-fluid type as well as vibration-dampers, shock-absorbers, or fluid springs comprising both a wound spring and a damper, e.g. a friction damper
    • F16F13/007—Units comprising springs of the non-fluid type as well as vibration-dampers, shock-absorbers, or fluid springs comprising both a wound spring and a damper, e.g. a friction damper the damper being a fluid damper
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16F—SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
    • F16F15/00—Suppression of vibrations in systems; Means or arrangements for avoiding or reducing out-of-balance forces, e.g. due to motion
    • F16F15/02—Suppression of vibrations of non-rotating, e.g. reciprocating systems; Suppression of vibrations of rotating systems by use of members not moving with the rotating systems
    • F16F15/04—Suppression of vibrations of non-rotating, e.g. reciprocating systems; Suppression of vibrations of rotating systems by use of members not moving with the rotating systems using elastic means
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16F—SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
    • F16F2222/00—Special physical effects, e.g. nature of damping effects
    • F16F2222/12—Fluid damping
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16F—SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
    • F16F2224/00—Materials; Material properties
    • F16F2224/02—Materials; Material properties solids
    • F16F2224/0208—Alloys
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16F—SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
    • F16F2228/00—Functional characteristics, e.g. variability, frequency-dependence
    • F16F2228/06—Stiffness
    • F16F2228/066—Variable stiffness
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16F—SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
    • F16F2238/00—Type of springs or dampers
    • F16F2238/02—Springs
    • F16F2238/026—Springs wound- or coil-like
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16F—SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
    • F16F2238/00—Type of springs or dampers
    • F16F2238/04—Damper

Definitions

  • the present invention relates generally to mechanisms for elastically connecting a mass to another mass, and more particularly to mechanisms for elastically connecting a mass to a vibrating mass where the mechanism is adjustable to vary the stiffness of the connection.
  • a Tuned Mass Damper is an assembly that includes a mass block connected by a stiffness element (spring) and a damping element to a structure where the structure vibrates when driven by an impressed force.
  • the purpose of the TMD is to reduce the vibration of the structure by transferring the vibrational energy to the TMD, and dissipating it through a damping (energy dissipating) element.
  • the TMD's vibration characteristics are tuned according to the structure's characteristics, so that the structure's motion causes amplified motion in the TMD.
  • a damping element located between the TMD and structure responds to the relative motion between the TMD and the structure, resulting in vibrational energy dissipation, reducing the motion of the structure.
  • the mass and natural frequency of the TMD are selected. Based on these values, a required stiffness value is determined.
  • Steel coil springs are generally used to provide the stiffness, however due to manufacturing tolerances and variation between spring units, the resulting stiffness often differs from the theoretical stiffness, and as a result, the natural frequency requirement is not achieved.
  • the natural frequency may be adjusted by changing the mass or the stiffness of the assembly. It is preferred to adjust the stiffness, as changing the mass will affect the TMD's effectiveness. Because coil springs are non-adjustable, adjustment of the stiffness is generally achieved by replacing coil springs with other coil springs, which have different dimensions, requiring changes to the spring mount geometry, resulting in delays and additional costs. Because the new coil springs are also likely to vary from their theoretical values, an iterative process results in further delays and additional costs.
  • the present invention provides an adjustable stiffness assembly for use in conjunction with a fixed stiffness element to elastically connect a structure to a mass.
  • the fixed stiffness element provides stiffness with respect to force in a global direction.
  • the adjustable stiffness assembly includes a structure mount that can be attached to the structure, a first mass mount that can be attached to the mass, and a first rotatable stiffness element.
  • the structure mount is spaced apart from the first mass mount.
  • the first rotatable stiffness element extends between the structure mount and the first mass mount and is rotatably engaged with the structure mount and the first mass mount.
  • the first rotatable stiffness element has a minimum stiffness value with respect to forces in a local direction referred to as X, and a maximum stiffness value with respect to forces in another local direction referred to as Y.
  • the maximum stiffness value is greater than the minimum stiffness value.
  • the fixed stiffness element and the adjustable stiffness assembly together provide a complete stiffness assembly having a total stiffness value with respect to force in the global direction for elastically connecting the mass and the structure.
  • the first rotatable stiffness element is rotatable relative to the structure mount and the first mass mount to vary the total stiffness value of the complete stiffness assembly with respect to force in the global direction.
  • the first rotatable stiffness element may be a beam having a longitudinal axis extending in a direction orthogonal to the X and Y directions between the structure mount and the mass mount, the beam having a non-circular cross-section orthogonal to the longitudinal axis.
  • the beam may have a rectangular cross-section orthogonal to the longitudinal axis, and the thickness of the beam in the X direction along a minimal stiffness axis of the beam may be less than the width of the beam in the Y direction along a maximal stiffness axis of the beam.
  • the fixed stiffness element may be one or more springs, each spring having constant stiffness.
  • the adjustable stiffness assembly may include a second rotatable stiffness element that is substantially the same as the first rotatable stiffness element and is rotatably engaged with the structure mount and the first mass mount.
  • the second rotatable stiffness element may have a minimum stiffness value with respect to forces in a local direction referred to as V, and a maximum stiffness value with respect to forces in another local direction referred to as W, wherein the maximum stiffness value is greater than minimum stiffness value.
  • the first and second rotatable stiffness elements may both be configurable by rotating them in opposite directions so that each rotatable stiffness element has substantially the same stiffness value with respect to forces in the global direction so that lateral forces on the stiffness elements are balanced when force is applied to the stiffness elements in the global direction.
  • the second rotatable stiffness element may be a beam with a longitudinal axis extending in a direction orthogonal to the V and W directions between the structure mount and the first mass mount.
  • the beam may have a non-circular cross-section orthogonal to the longitudinal axis.
  • the invention also provides a tuned mass damper including a mass block assembly and a damper stiffness assembly.
  • the damper stiffness assembly includes a fixed stiffness element attached to the mass block assembly, and an adjustable stiffness assembly having a stiffness value with respect to force in the global direction.
  • the fixed stiffness element provides stiffness with respect to force in a global direction.
  • the adjustable stiffness has a stiffness value with respect to force in the global direction.
  • the adjustable stiffness assembly includes a structure mount that can be attached to a structure, a first mass block assembly mount attached to the mass block assembly, and a first rotatable stiffness element. The structure mount is spaced apart from the first mass block assembly mount.
  • the first rotatable stiffness element extends between the structure mount and the first mass block assembly mount and is rotatably engaged with the structure mount and the mass block assembly mount.
  • the first rotatable stiffness element has a minimum stiffness value with respect to forces in a local direction referred to as X, and a maximum stiffness value with respect to forces in another local direction referred to as Y.
  • the maximum stiffness value is greater than minimum stiffness value.
  • the damper stiffness assembly elastically connects the mass block assembly and the structure.
  • the first rotatable stiffness element is rotatable relative to the structure mount and the first mass block assembly mount to vary the total stiffness value of the damper stiffness assembly with respect to force in the global direction.
  • the first rotatable stiffness element may be a beam having a longitudinal axis extending in a direction orthogonal to the X and Y directions between the structure mount and the first mass block assembly mount, and the beam may have a non-circular cross-section orthogonal to the longitudinal axis.
  • the beam may have a rectangular cross-section orthogonal to the longitudinal axis, and the thickness of the beam in the X direction along a minimal stiffness axis of the beam may be less than the width of the beam in the Y direction along a maximal stiffness axis of the beam.
  • the adjustable stiffness assembly may also include a second rotatable stiffness element that is substantially the same as the first rotatable stiffness element.
  • the second rotatable stiffness element is rotatably engaged with the structure mount and the mass block assembly mount and positioned so that the longitudinal axes of the rotatable stiffness elements are parallel to each other.
  • the second rotatable stiffness element may have the minimum stiffness value with respect to forces in a local direction referred to as V, and the maximum stiffness value with respect to forces in another local direction referred to as W.
  • the first and second rotatable stiffness elements are configurable by rotating them in opposite directions so that each rotatable stiffness element has substantially the same stiffness value with respect to forces in the global direction so that lateral forces on the stiffness elements are balanced.
  • the mass block assembly may consist of a frame that is attachable to the first mass block assembly mount and a mass block supported by the frame.
  • the mass block assembly may include multiple steel mass blocks supported by the frame.
  • the fixed stiffness element may include one or more springs, each spring having constant stiffness.
  • the adjustable stiffness assembly may also include a second mass block assembly mount attached to the mass block assembly. In such embodiments, the first and second mass block assembly mounts are rotatably engaged with the first rotatable stiffness element at opposite ends of the first rotatable stiffness element, and the structure mount being rotatably engaged with a central portion of the first rotatable stiffness element.
  • the tuned mass damper may include a second mass block assembly mount attached to the mass block assembly, where the beam has first and second ends and a middle section, and where the first mass block assembly mount is rotatably engaged with the beam near the first end of the beam.
  • the second mass block assembly mount may be rotatably engaged with the beam near the second end of the beam, and the structure mount may be rotatably engaged with the middle section of the beam.
  • the invention also provides an adjustable stiffness assembly for elastically connecting a structure to a mass.
  • the adjustable stiffness assembly has a global stiffness value with respect to force in a global direction.
  • the adjustable stiffness assembly includes a structure mount that can be attached to the structure, a mass mount that can be attached to the mass, and a first rotatable stiffness element.
  • the structure mount is spaced apart from the mass mount being spaced apart.
  • the first rotatable stiffness element extends between the structure mount and the mass mount and is rotatably engaged with the structure mount and the mass mount.
  • the first rotatable stiffness element has a minimum stiffness value with respect to forces in a local direction referred to as X, and a maximum stiffness value with respect to forces in another local direction referred to as Y.
  • the maximum stiffness value is greater than minimum stiffness value.
  • the first rotatable stiffness element is rotatable relative to the structure mount and the mass mount to vary the global stiffness value of the adjustable stiffness assembly.
  • the first rotatable stiffness element may be a beam having a longitudinal axis extending in a direction orthogonal to the X and Y directions between the structure mount and the mass mount, and the beam may have a non-circular cross-section orthogonal to the longitudinal axis.
  • the adjustable stiffness assembly may include a second rotatable stiffness element that is substantially the same as the first rotatable stiffness element and is rotatably engaged with the structure mount and the mass mount. In such embodiments, the second rotatable stiffness element has a minimum stiffness value with respect to forces in one direction, and a maximum stiffness value with respect to forces in another direction, where the maximum stiffness value is greater than the minimum stiffness value
  • FIGS. 1 a , 1 b and 1 c are three end views of a rotatable stiffness element in the form of a beam with a rectangular cross-section in three different rotational positions.
  • FIG. 2 is a perspective view of an adjustable stiffness assembly.
  • FIG. 3 is a perspective view of another embodiment of an adjustable stiffness assembly.
  • FIG. 4 is a perspective view of a tuned mass damper assembly utilizing an adjustable stiffness assembly.
  • FIG. 5 is a side view of the tuned mass damper assembly of FIG. 4 showing the adjustable stiffness assembly.
  • the present invention provides an adjustable stiffness assembly, optionally for use in conjunction with one or more fixed stiffness elements, to elastically connect a structure to a mass.
  • a structure may be, for example, a high-rise building.
  • the mass may be an assembly of metal mass blocks attached to a frame, for example. Such a mass when placed near the top of a tall building and elastically connected to the building can act as a tuned mass damper to reduce the amplitude of mechanical vibrations, which can be useful in preventing or reducing discomfort, damage or structural failure that might otherwise be cause by harmonic motion of the building.
  • the ability to adjust the stiffness of the adjustable stiffness assembly allows systems employing the adjustable stiffness assembly to be tuned, for example, to either move the main mode away from a troubling excitation frequency, or to add damping to a resonance that is difficult or expensive to damp directly.
  • a key element of the adjustable stiffness assembly is a rotatable stiffness element.
  • a preferred embodiment of the rotatable stiffness element is a beam 100 with a rectangular cross section as shown in the adjustable stiffness assembly 200 of FIG. 2 , and shown in an end view in three rotational positions in FIGS. 1 a , 1 b and 1 c .
  • the beam 100 is extended along a longitudinal axis in a local direction that may be referred to as the “Z” direction.
  • Such a beam 100 is typically made of metal, such as steel, which can bend under forces not aligned with the longitudinal axis.
  • the resistance to bending under a force represents the stiffness of the beam 100 , and the stiffness varies according to the direction of the force.
  • the beam While it is preferred that the beam have a cross-section perpendicular to the longitudinal axis that is rectangular at most points in the beam, and not square, it is not essential that it be rectangular, in whole or in part. Rather it is only necessary that the beam have a non-circular cross-section orthogonal to the longitudinal axis. This results in the rotatable stiffness element having a minimum stiffness value with respect to forces in a local direction referred to as X, and a larger maximum stiffness value with respect to forces in another local direction referred to as Y, where the X and Y axes are both orthogonal to Z.
  • the X axis extends through the beam 100 orthogonal to the two wide surfaces of the beam 100 (i.e. the extent of the X axis through the beam 100 is the thickness of the beam 100 ), and the Y axis extends through the beam 100 orthogonal to the two narrow surfaces of the beam 100 (i.e. the extent of the Y axis through the beam 100 is the width of the beam 100 ). More generally, it is simply required that the second moment of area around the X axis (I xx ) differs from its second moment of area around the Y axis (I yy ).
  • the term “local direction” in the context of an element such as a beam is intended to mean that the direction is relative to the beam.
  • the beam 100 When the beam 100 is aligned so that the Z axis is orthogonal to a particular principal or global direction, which may be vertical/downward corresponding to the direction of gravitational force, the beam 100 presents a stiffness value to forces in the global direction that depends on the rotational position of the beam 100 .
  • the stiffness value in the global direction is minimal when the X axis is oriented in the global direction, as in FIG. 1 a , taking the global direction to be downward.
  • the stiffness value in the global direction is maximal when the Y axis is oriented in the global direction, as in FIG. 1 b .
  • the stiffness value in the global direction continuously increases until reaching the maximum value in the position shown in FIG. 1 b .
  • the stiffness value in the global direction is intermediate between the minimum and maximum values.
  • the stiffness value in the global direction may be selected to be any value between the minimum and maximum values.
  • the adjustable stiffness assembly 200 includes a mass mount 201 and a structure mount 202 .
  • the beam 100 extends between the mass mount 201 and structure mount 202 and the beam 100 is rotatably connected to each mount so that the beam 100 may be rotated and secured in any rotational position.
  • the adjustable stiffness assembly 200 elastically connects the mass and structure and provides a stiffness value in the global direction. The beam 100 can be rotated to vary the stiffness value in the global direction.
  • FIG. 2 employs only one rotatable stiffness element (the beam 100 ) and one mass mount 201 .
  • FIG. 3 shows an embodiment of an adjustable stiffness assembly 300 with two beams 303 a , 303 b used as rotatable stiffness elements and two mass mounts 301 a , 301 b , with a structure mount 302 intermediate between the two mass mounts 301 a , 301 b .
  • Each beam 303 a , 303 b is rotatably connected to each of the two mass mounts 301 a , 301 b and the structure mount 302 .
  • FIG. 3 shows an embodiment of an adjustable stiffness assembly 300 with two beams 303 a , 303 b used as rotatable stiffness elements and two mass mounts 301 a , 301 b , with a structure mount 302 intermediate between the two mass mounts 301 a , 301 b .
  • Each beam 303 a , 303 b is rotat
  • each beam 303 a , 303 b has three portions with a circular cross section orthogonal to the longitudinal axis designed to mate with cylindrical openings in the mass mounts 301 a , 301 b and the structure mount 302 while still allowing rotation of the beams 303 a , 303 b relative to the mounts.
  • the two beams 303 a , 303 b are rotated in opposite directions.
  • the system provides a variable stiffness in the vertical direction without any other effects/consequences/influence on the TMD system.
  • the first beam 303 a may be rotated clockwise around the longitudinal axis by N degrees (N being a number between 0 and 90) and the second beam 303 b may be rotated counter-clockwise by N degrees.
  • Such an approach is preferable because lateral forces on the beams 303 a , 303 b are then balanced when force is applied to the beams 303 a , 303 b in the global direction.
  • the shear centre of the rotated beam is no longer coincident with the beam centroid and lateral forces are generated, but this is not the case when two beams rotated in opposite directions are employed because the lateral forces balance one another.
  • the two beams 303 a , 303 b shown in FIG. 3 may extend through the structure mount 302 so that there are only two separate rotatable stiffness elements. Alternatively, there may be four or more pairs of separate rotatable stiffness elements such that the portions on either side of the structure mount 302 are independently rotatable. This is generally preferred in order to provide to provide a balance of the stiffnesses of the adjustable stiffness assemblies with respect to the centre of gravity of the mass block.
  • the adjustable stiffness assembly further includes one or more fixed stiffness elements, such as steel coil springs 405 as shown in FIG. 4 .
  • the adjustable stiffness assembly can provide an arbitrarily large total stiffness value in the global direction (being the sum of the stiffnesses of all the fixed stiffness elements and the rotatable stiffness elements in the global direction) such that the total stiffness value can be varied by rotating the rotatable stiffness elements.
  • the maximum variation is then the difference between the sum of the maximum stiffness values of the rotatable stiffness elements and the sum of the minimum stiffness values of the rotatable stiffness elements.
  • FIG. 4 depicts a TMD incorporating two adjustable stiffness assemblies 401 according to the present invention.
  • a damper stiffness assembly elastically connects a mass block assembly having mass blocks 407 supported by a frame 408 to a structure 406 .
  • the depicted structure 406 in FIG. 4 is two I-beams which may be rigidly attached to a large structure, such as a building.
  • the frame 408 is rigidly connected to two adjustable stiffness assemblies 401 , one on each side (only one spring 405 of the rear adjustable stiffness assembly is visible in FIG. 4 ).
  • Each adjustable stiffness assembly 401 includes rotatable stiffness elements 404 rotatably connected to a structure mount 403 and two mass mounts 402 a , 402 b , and two fixed stiffness elements in the form of steel coil springs 405 .
  • the mass mounts 402 a , 402 b are rigidly connected to the frame 408 of the mass block assembly, and the structure mount 403 is rigidly connected to a beam 406 that is part of the structure.
  • the mass mounts 402 a , 402 b are rigidly connected to the frame 408 of the mass block assembly via holes 410 through the frame 408 as depicted in FIG. 4 .
  • the depicted adjustable TMD also includes two damping elements 409 used in conjunction with each adjustable stiffness assembly 401 to dissipate vibrational energy.
  • Each damping element 409 which are typically hydraulic damping elements, connects to both the structure 406 and the frame 408 of the mass block assembly, as can be seen in FIG. 5 .
  • the adjustable stiffness assemblies 401 provide an elastic connection between the frame 408 of the mass block assembly and the beams 406 of the structure. Relative motion of the mass block assembly and the structure 206 results in force being applied to the beams 404 causing a bending stress. Generally such force is in the global direction which can be taken to be downward in the figures.
  • the total stiffness of the adjustable stiffness assemblies 401 can beadjusted, as discussed above, by rotating one or more of the rotatable stiffness elements 404 .
  • a TMD employing the adjustable stiffness assembly may include a mechanism to minimize the lateral forces that result when the force is not perpendicular to one of the beam's principal stiffness axes. This may be achieved by limiting the direction of the relative motion between the two structures, or by utilizing a symmetric group of springs to provide equal and opposite lateral forces such that no net lateral force is applied to the structure.

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US15/638,882 2016-06-30 2017-06-30 Adjustable stiffness assembly Abandoned US20180002923A1 (en)

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Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9915079B2 (en) * 2014-04-23 2018-03-13 Architectural Design & Research Institute Of South China University of Technology Variable-rigidity seismic-isolation layer rigidity control mechanism suitable for structural seismic isolation and wind resistance
CN108824694A (zh) * 2018-08-28 2018-11-16 湖南食品药品职业学院 一种梁结构的刚度调节装置
CN109914632A (zh) * 2019-03-28 2019-06-21 云南震安减震科技股份有限公司 调谐质量阻尼器
US11216742B2 (en) 2019-03-04 2022-01-04 Iocurrents, Inc. Data compression and communication using machine learning
JP7504765B2 (ja) 2020-10-21 2024-06-24 住友理工株式会社 制振装置用ベース部材とそれを用いた小規模建築物用制振装置

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111282963A (zh) * 2020-03-03 2020-06-16 陆安培 一种兽医站用废弃物处理设备
CN112031194B (zh) * 2020-08-31 2021-05-28 中交第二航务工程局有限公司 带有电涡流阻尼器的tmd装置

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1540734A (en) * 1924-03-08 1925-06-02 Manuf Generale De Ressorts Laminated suspension spring for automobiles and other vehicles
US1596321A (en) * 1925-05-21 1926-08-17 Walker H Spayd Vehicle spring clamp
US20080308368A1 (en) * 2005-02-02 2008-12-18 A2 Acoustics Ab Device for Reducing Vibrations and Sounds
US20110017561A1 (en) * 2009-07-24 2011-01-27 Tanaka Seishin Kozo Laboratory Inc. Vibration damping apparatus
US20110079478A1 (en) * 2005-02-02 2011-04-07 Mats Gustavsson Device for Reducing Vibrations and Sounds
US20140048989A1 (en) * 2012-08-16 2014-02-20 Minus K. Technology, Inc. Vibration isolation systems

Family Cites Families (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US989958A (en) 1909-10-30 1911-04-18 Hermann Frahm Device for damping vibrations of bodies.
GB617076A (en) 1945-12-04 1949-02-01 Edmund Ramsay Wigan Improvements in or relating to spring assemblages
US2744748A (en) * 1952-12-22 1956-05-08 Hamilton Thomas Corp Zero scale spring
FR2639175B1 (fr) * 1988-12-06 1991-07-26 Geiver Sa Appareil vibrateur portatif pour la recolte des fruits
US6676118B2 (en) 2001-08-13 2004-01-13 Cheng-Ming Chou Adjustable casing for helical spring
US6681908B2 (en) 2002-01-08 2004-01-27 Honeywell International, Inc. Adjustable tuned mass damper
ES2233168B1 (es) * 2003-02-21 2006-07-16 Jose Gurri Molins Elemento de absorcion y aislamiento de componentes bi-o-tri-dimensionales de movimiento , aplicable a maquinas, dispositivos e implementos mecanicos.
DE10311442A1 (de) * 2003-03-15 2004-09-23 Daimlerchrysler Ag Fahrwerksfederung
US7992849B2 (en) 2004-09-21 2011-08-09 Thomas Sugar Adjustable stiffness jack spring actuator
US8044629B2 (en) 2008-08-29 2011-10-25 Northern Illinois University Self-tuning vibration absorber
CN109723747B (zh) * 2019-01-30 2023-09-01 浙江大学 一种基于耦合旋转梁的动力吸振器及其吸振方法

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1540734A (en) * 1924-03-08 1925-06-02 Manuf Generale De Ressorts Laminated suspension spring for automobiles and other vehicles
US1596321A (en) * 1925-05-21 1926-08-17 Walker H Spayd Vehicle spring clamp
US20080308368A1 (en) * 2005-02-02 2008-12-18 A2 Acoustics Ab Device for Reducing Vibrations and Sounds
US20110079478A1 (en) * 2005-02-02 2011-04-07 Mats Gustavsson Device for Reducing Vibrations and Sounds
US20110017561A1 (en) * 2009-07-24 2011-01-27 Tanaka Seishin Kozo Laboratory Inc. Vibration damping apparatus
US20140048989A1 (en) * 2012-08-16 2014-02-20 Minus K. Technology, Inc. Vibration isolation systems

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9915079B2 (en) * 2014-04-23 2018-03-13 Architectural Design & Research Institute Of South China University of Technology Variable-rigidity seismic-isolation layer rigidity control mechanism suitable for structural seismic isolation and wind resistance
CN108824694A (zh) * 2018-08-28 2018-11-16 湖南食品药品职业学院 一种梁结构的刚度调节装置
US11216742B2 (en) 2019-03-04 2022-01-04 Iocurrents, Inc. Data compression and communication using machine learning
CN109914632A (zh) * 2019-03-28 2019-06-21 云南震安减震科技股份有限公司 调谐质量阻尼器
JP7504765B2 (ja) 2020-10-21 2024-06-24 住友理工株式会社 制振装置用ベース部材とそれを用いた小規模建築物用制振装置

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