SYSTEM AND METHOD FOR TUNING THE RESONANCE FREQUENCY OF AN ENERGY ABSORBING DEVICE FOR A STRUCTURE IN RESPONSE TO A DISRUPTIVE FORCE

• US 20100320045A1
• Filed: 04/04/2008
• Published: 12/23/2010
• Est. Priority Date: 04/04/2008
• Status: Active Grant

• Current Assignee: Martin A. Muska
• Original Assignee: Martin A. Muska
• Inventors: Muska, Martin A.
• Granted Patent: US 8,127,904 B2
• Time in Patent Office: Days
• US Class Current: 188/378
• CPC Class Codes: E04H 9/022 and comprising laminated structures of alternating elastomeric and rigid layers
• CPC Class Codes: E04H 9/0235 Anti-seismic devices with hydraulic or pneumatic damping
• CPC Class Codes: F16F 7/00 Vibration-dampers; Shock-absorbers using fluid F16F5/00, F16F9/00; specific for rotary systems F16F15/10 ; belt tensioners F16H7/12
• CPC Class Codes: G05B 15/02 electric
• CPC Class Codes: G08C 17/00 Arrangements for transmitting signals characterised by the use of a wireless electrical link
• CPC Class Codes: G08C 2201/51 Remote controlling of devices based on replies, status thereof

Abstract

The invention is a system and method for automatically adjusting the resonance frequency of an energy absorbing device in response to a disruptive force. By configuring an energy absorbing device for automatic response tuning, utilizing a controller coupled to one or more sensors for processing a determination primarily based on sensing data, the natural period of an overall structure may be adjusted (i.e. increased or decreased) so that the acceleration response of the structure is decreased upon being subjected to a disruptive force, for example, high winds, a blast from an explosion, or a seismic force caused by an earthquake.

Claims

1. An automatic energy dissipation system, comprising:

a sensor for detecting a disruptive force applied to a structure;

a processor connected to said sensor, configured for determining a control signal based on a sensing data received from said sensor;

an energy absorbing device for coupling to said structure; and

an actuator, coupled to said processor and connected to said energy absorbing device, for tuning said energy absorbing device based on said control signal generated by said processor.

2. The system of claim 1, wherein said tuning of said energy absorbing device comprises altering a resonance frequency of said structure to reduce a structural response to said disruptive force applied to said structure.

3. The system of claim 1, wherein said tuning of said energy absorbing device comprises generating a damping force to reduce a structural response to said disruptive force applied to said structure.

4. The system of claim 3, wherein generating said damping force comprises viscous damping.

5. The system of claim 3, wherein generating said damping force comprises hysteretic damping.

6. The system of claim 3, wherein said energy absorbing device further comprises a variable friction damper.

7. The system of claim 3, wherein said energy absorbing device further comprises a variable viscous damper.

8. The system of claim 1, wherein said energy absorbing device is a base isolator configured for:

adjusting a resonance frequency of said structure; and

generating a damping force to reduce a structural response to said disruptive force applied to said structure.

9. The system of claim 8, wherein said base isolator further comprises:

a base adapted to attach to a support member of said structure;

a cover coupled to said base in a manner so as to form an enclosure, wherein said cover is adapted to attach to said base and said structure; and

an energy absorbing material situated within said enclosure, wherein said enclosure is coupled to said actuator in a manner so that a stiffness of said enclosure may be controlled by activating said actuator.

10. The system of claim 9, wherein said cover of said base isolator further comprises:

a rigid layer;

a resilient layer; and

a plurality of side plates;

wherein said rigid layer and said resilient layer are substantially semicircular in shape, having substantially the same center and having respective ends configured to attach to said base; and

wherein said rigid layer acts as a restraining material for said resilient layer when said disruptive force is applied to said cover.

11. The system of claim 10, wherein said resilient layer of said cover is securely sandwiched between said side plates, said side plates being coupled to said actuator to adjust said damping force when said actuator is activated for said tuning.

12. The system of claim 9, wherein said cover is coupled to said support member of said structure near a top portion of said semicircular shape.

13. The system of claim 12, wherein said respective ends of said cover are coupled to a foundation of said structure to provide a constant factor of initial and sliding friction between said rigid layer and said resilient layer for transferring tension and shear forces away from said structure.

14. The system of claim 13, further comprising a plurality of actuators adapted to attach to said cover at said respective ends and said top portion of said semicircular shape for:

tuning said constant factor of initial and sliding friction between said rigid layer and said resilient layer; and

tuning said transferring tension and shear forces away from said structure.

15. The system of claim 9, wherein said energy absorbing material enclosed in said cover of said base isolator further comprises a granular material, which provides vertical strength and allows for sideways slip when said disruptive force is applied.

16. The system of claim 9, wherein said energy absorbing material enclosed in said cover of said base isolator further comprises a liquid, which provides vertical strength and allows for sideways slip when said disruptive force is applied.

17. The system of claim 16, wherein said cover further comprises a valve to transfer said liquid into a spring loaded chamber whenever said disruptive force is applied;

said spring loaded chamber having a spring positioned to push said liquid back into said cover whenever said cover is relieved from said disruptive force.

18. A method for protecting a structure from disruptive forces, comprising the steps of:

generating sensing data related to a disruptive force using a sensor;

receiving said sensing data from said sensor;

generating a control signal based on said sensing data from a determination based on a constant data and said sensing data received from said sensor; and

tuning said energy absorbing device based on said control signal.

19. The method of claim 18, wherein the step of tuning said energy absorbing device comprises altering a resonance frequency of said structure to reduce a structural response to said disruptive force applied to said structure.

20. The method of claim 18, wherein said tuning of said energy absorbing device comprises further comprises generating a damping force to reduce a structural response to said disruptive force applied to said structure.

21. The method of claim 20, wherein generating said damping force comprises viscous damping.

22. The method of claim 20, wherein generating said damping force comprises hysteric damping.

23. The method of claim 20, wherein said energy absorbing device further comprises a variable friction damper.

24. The method of claim 20, wherein said energy absorbing device further comprises a variable viscous damper.

25. The method of claim 18, wherein said energy absorbing device comprises a base isolator configured to be tuned by said actuator for:

adjusting a resonance frequency of said structure; and

generating a damping force to reduce a structural response to said disruptive force applied to said structure.

26. The method of claim 25, wherein configuring said base isolator further comprises the steps of:

forming an enclosure containing an energy absorbing material;

coupling said enclosure to a foundation of said structure;

coupling said enclosure to said structure; and

coupling said actuator to said base isolator in a manner so that a stiffness of said enclosure may be controlled by activating said actuator.

27. The method of claim 26, wherein forming said enclosure further comprises the steps of:

enclosing said energy absorbing material with a cover, said cover comprising;

a rigid layer;

a resilient layer; and

a plurality of side plates;

wherein said rigid layer and said resilient layer are substantially semicircular in shape, having substantially the same center and having respective ends configured to attach to said base; and

wherein said rigid layer acts as a restraining material for said resilient layer when a disruptive force is applied to said cover.

28. The method of claim 27, wherein forming said enclosure, further comprises the step of:

securely sandwiching said cover between said side plates to create a frictional force that is damping when said disruptive force occurs.

29. The method of claim 28, wherein coupling said enclosure to said foundation of said structure further comprises the step of:

coupling said respective ends of said cover to said foundation, to provide a constant factor of initial and sliding friction between said rigid layer and said resilient layer for transferring tension and shear forces away from said structure.

30. The method of claim 29, wherein coupling said enclosure to said structure, further comprises the step of:

coupling said cover to said structure near a top portion of said semicircular shape for providing a load path between the ground and said structure, wherein a displacement caused by said disruptive force allows the ground to move independently of said structure.

31. The method of claim 30, further comprising the steps of:

connecting a plurality of actuators coupled to said cover at said respective ends of said cover and said top portion of said semicircular shape of said cover for;

tuning said constant factor of initial and sliding friction between said rigid layer and said resilient layer; and

tuning said transferring of tension and shear forces away from said structure.

32. The method of claim 31, wherein forming said enclosure containing said energy absorbing material further comprises the step of:

filling said enclosure with a granular material that provides a vertical strength and allows for a sideways slip when said disruptive force is applied.

33. The method of claim 27, wherein forming said enclosure containing said energy absorbing material further comprises the step of:

filling said enclosure with a liquid that provides a vertical strength and allows for a sideways slip when said disruptive force is applied.

34. The method of claim 33, further comprising the step of:

adapting a valve connected to said cover for transferring said liquid into a spring loaded chamber whenever said disruptive force is applied;

said spring loaded chamber having a spring positioned to push said liquid back into said cover whenever said cover is relieved from said disruptive force.

35. An automatic energy dissipation system, comprising:

a sensor for detecting a disruptive force applied to a structure;

a processor connected to said sensor, configured for determining a control signal based on a sensing data received from said sensor;

a base isolator for coupling to said structure, said base isolator further comprising;

a base adapted to attach to a support member of said structure,

a cover coupled to said base in a manner so as to form an enclosure, wherein said cover is adapted to attach to said base and said structure, and

an energy absorbing material situated within said enclosure; and

an actuator, coupled to said processor and connected to said base isolator in a manner so that a stiffness of said enclosure may be controlled by activating said actuator, for tuning said base isolator based on said control signal generated by said processor, wherein said tuning of said base isolator is for altering a resonance frequency of said structure to reduce a structural response to said disruptive force applied to said structure, and generating a damping force to reduce a structural response to said disruptive force applied to said structure.