Displacement amplification method and apparatus for passive energy dissipation in seismic applications

• US 6,672,573 B2
• Filed: 06/15/2001
• Issued: 01/06/2004
• Est. Priority Date: 06/16/2000
• Status: Expired due to Fees

• Current Assignee: Stefano Berton
• Original Assignee: Stefano Berton
• Inventors: Berton, Stefano
• Primary Examiner(s): Schwartz, Christopher P.
• Application Number:
  US09/882,937
• Publication Number:
  US 20010054785A1
• Time in Patent Office: 935 Days
• Field of Search: 188/378-381, 267/136, 248/636-638, 248/550, 521/671-167
• US Class Current: 267/136
• CPC Class Codes: E04H 9/0235 Anti-seismic devices with hydraulic or pneumatic damping
• CPC Class Codes: E04H 9/0237 Structural braces with damping devices
• CPC Class Codes: E04H 9/028 Earthquake withstanding shelters

Abstract

An apparatus and method of dissipating inter floor seismic energy within buildings and other large structures which are subject mechanical deformation in response to seismic activity, wind shear, vibration, and so forth. The present invention provides displacement amplification methods and apparatus which increase the dissipation of seismic energy that is coupled from the building under deformation to a seismic damper. By way of example, the displacement amplifier is exemplified in a number of embodiments that utilize mechanical lever arms, gear sets, and combination amplifier/dampers to amplify energy dissipation.

Claims

1. An apparatus for placement within the gravity frame of a structure which amplifies inter story structural displacements to increase passive energy dissipation, comprising:

(a) a reaction frame rigidly coupled to a base level;

(b) means for amplifying mechanical displacement coupled between said reaction frame and said gravity frame, said means for amplifying mechanical displacement having a mechanical output; and

(c) a damping device coupled to the mechanical output of said means for amplifying displacement;

(d) said means for amplifying mechanical displacement comprising

(i) a generally concentric rotating gearset having a first gear connected to a larger second gear;

(ii) said first gear being coupled to a first linear coupling member subject to the relative linear displacement of the gravity frame in relation to the reaction frame;

(iii) said second gear coupled to a second linear coupling member which is attached to said damper device.

2. An apparatus as recited in claim 1, wherein the mechanical displacement applied to the damping device is amplified by the ratio of the diameter of a larger gear coupled to the damping device in relation to the diameter of a smaller gear coupled to a linear coupling member subject to the relative displacement of the gravity frame relation to the position of the reaction frame, wherein said smaller gear is connected for substantially concentric rotation with said larger gear.

3. An apparatus as recited in claim 1, wherein the coupling between the gears and the linear coupling members comprises a rack-pinion coupling mechanism.

4. An apparatus as recited in claim 1, wherein said mechanical displacement amplifying means is combined with said damping device within a rotating damper, said rotating damper comprising:

(a) a linear coupling member subject to the displacement of the gravity frame in relation to the reaction frame;

(b) a gear-driven propeller coupled to said linear coupling member and configured to amplify the motion of the linear coupling member into the rotational motion of said propeller; and

(c) a housing filled with fluid surrounding said propeller.

5. An apparatus as recited in claim 4, wherein said coupling between said linear coupling member and said gear drive propeller is provided by a rack-pinion coupling mechanism.

6. An apparatus as recited in claim 4, wherein said linear coupling member is configured with multiple pinions for driving multiple gear-driven propellers.

7. An apparatus as recited in claim 6, wherein said multiple gear-driven propellers are configured for counter-rotation in close proximity to one another within said fluid filled housing.

8. An apparatus as recited in claim 1, wherein said damping device comprises an energy dissipation device configured for damping mechanical movement.

9. An apparatus as recited in claim 1, wherein said damping device comprises a fluid viscous damper.

10. An apparatus as recited in claim 1, wherein said damping device comprises a friction damper.

11. An apparatus as recited in claim 1, wherein said damping device comprises a viscous elastic damper.

12. An apparatus as recited in claim 1, wherein said reaction frame comprises a triangular structure configured for positioning beneath a horizontal support of said gravity frame.

13. An apparatus as recited in claim 12, wherein said reaction frame further comprises a slidable coupling attached to said triangular structure which supports said horizontal support within said gravity frame and restricts motion therein to substantially lateral movement.

14. An apparatus as recited in claim 13, wherein said slidable coupling incorporates rollers configured to allow lateral displacement of said horizontal support.

15. An apparatus as recited in claim 12 wherein said triangular structure comprises a pair of legs rigidly having proximal ends attached to the base level and distal ends fixedly joined to one another to provide a support for said mechanical displacement amplifier.

16. An apparatus as recited in claim 12, wherein said damping device is mounted within said triangular structure.

17. An apparatus as recited in claim 1, wherein said damping device is mounted within the gravity frame.

18. An apparatus as recited in claim 1, wherein said reaction frame comprises:

(a) a housing rigidly attached to the base level;

(b) said housing configured to receive said means for amplifying mechanical displacement;

(c) a diagonal support member having a distal end configured for attachment to said gravity frame at a selected location;

(d) said diagonal support member having a proximal end configured for attachment to said means for amplifying mechanical displacement such that displacement of said gravity frame at said location will induce movement of said diagonal support.

19. An apparatus for placement within a gravity frame of a structure which passively dissipates energy from structural displacements of said gravity frame, comprising:

(a) a reaction frame rigidly coupled to a base level;

(b) a mechanical displacement amplifier having an input coupled between said reaction frame and said gravity frame; and

(c) a damper assembly coupled to the mechanical output of said displacement amplifier;

(d) wherein the mechanical displacement amplifier comprises

(i) a gearset which is substantially concentric and contains gears of different diameters;

(ii) a first gear within said gearset coupled to a linear coupling member subject to the relative displacement of the gravity frame relation to the position of the reaction frame; and

(iii) a second gear, of larger diameter than said first gear to amplify linear motion received therein, coupled to a linear coupling member which urges movement within said damper assembly.

21. An apparatus as recited in claim 19 or 20, wherein the coupling between the first gear and the linear coupling member is provided by rack and pinion coupling.

22. An apparatus as recited in claim 19 or 20, wherein said mechanical displacement amplifier is combined with said damper assembly within a rotating damper, comprising:

(a) a linear coupling member subject to the relative displacement of the gravity frame in relation to the reaction frame;

(b) a gear-driven propeller coupled to said linear coupling member and configured to amplify the linear displacement of the linear coupling member into the rotational motion of said propeller; and

(c) a housing filled with viscous fluid surrounding said propeller.

23. An apparatus as recited in claim 22, wherein said coupling between said linear coupling member and said gear drive propeller is provided by a rack-pinion coupling.

24. An apparatus as recited in claim 22, wherein said linear coupling member is configured with multiple pinions for driving multiple gear-driven propellers.

25. An apparatus as recited in claim 24, wherein said multiple gear-driven propellers are configured for counter-rotation in close proximity to one another within said fluid filled housing.

26. An apparatus as recited in claim 19 or 20, wherein said damper assembly provides energy dissipation to damp the mechanical distortions of the gravity frame in relation to the reaction frame.

27. An apparatus as recited in claim 19 or 20, wherein said damper assembly comprises a fluid viscous damper.

28. An apparatus as recited in claim 19 or 20, wherein said damper assembly comprises a friction damper.

29. An apparatus as recited in claim 19 or 20, wherein said damper assembly comprises a viscous elastic damper.

30. An apparatus as recited in claim 19 or 20, wherein said reaction frame comprises a triangular structure configured for positioning beneath a horizontal support of said gravity frame.

31. An apparatus as recited in claim 30, wherein said reaction frame further comprises a slidable coupling attached to said triangular structure which supports said horizontal support within said gravity frame end restricts motion therein to substantially lateral movements.

32. An apparatus as recited in claim 31, wherein said slidable coupling incorporates rollers configured to allow lateral displacements of said horizontal support.

33. An apparatus as recited in claim 30, wherein said triangular structure comprises a pair of legs rigidly having proximal ends attached to the base level and distal ends fixedly joined to one another to provide a support for said mechanical displacement amplifier.

34. An apparatus as recited in claim 30, wherein said damper assembly is mounted within said triangular structure.

35. An apparatus as recited in claim 19 or 20, wherein said damper assembly is mounted within the gravity frame.

36. An apparatus as recited in claim 19 or 20, wherein said reaction frame comprises:

(a) a housing rigidly attached to the base level;

(b) said housing configured to receive said mechanical displacement amplifier;

(c) a diagonal support member having a distal end configured for attachment to said gravity frame at a selected location;

(d) said diagonal support member having a proximal end configured for attachment to said mechanical displacement amplifier such that displacement of said gravity frame at said location will induce movement of said diagonal support.

20. An apparatus for placement within a gravity frame of a structure which passively dissipates energy from structural displacements of said gravity frame, comprising:

(a) a reaction frame rigidly coupled to a base level;

(b) a mechanical displacement amplifier having an input coupled between said reaction frame and said gravity frame; and

(c) a damper assembly coupled to the mechanical output of said displacement amplifier;

(d) wherein said mechanical displacement amplifier comprises a generally concentric rotating gearset having a first gear attached to a larger second gear;

(e) wherein said first gear is coupled to a first linear coupling member subject to the relative linear displacement of the gravity frame in relation to the reaction frame; and

(f) wherein said second gear is coupled to a second linear coupling member which is attached to said damper assembly.

37. A seismic isolator configured for attachment between a rigid structure and a flexible structure to dissipate seismic energy, comprising:

(a) means for mechanically amplifying movement of said flexible structure in relation to the position of said rigid structure, said means for mechanically amplifying movement having a mechanical output; and

(b) a damper coupled to the mechanical output of said mechanical amplifying means;

(c) wherein the means for mechanically amplifying movement comprises

(i) concentric rotating gearset having gears of different diameters;

(ii) a small diameter first gear within set gearset coupled to a first linear coupling member subject to the motion of the flexible structure in relation to rigid structure; and

(iii) a large diameter second gear which amplifies the motion received by said first clear and couples to a second linear coupling member which is received by said damper to dissipate mechanical energy.

39. A seismic isolator as recited in claim 37 or 38, wherein the coupling between the gears and the linear coupling members is provided by rack-pinion coupling.

40. A seismic isolator as recited in claim 37 or 38, wherein the means for mechanically amplifying movement is combined with said damper within a rotating damper assembly, comprising:

(a) a third linear coupling member subject to the relative displacement of the gravity frame in relation to the reaction frame;

(b) a gear-driven propeller coupled to said third linear coupling member and configured to amplify the linear displacement of the third linear coupling member into the rotational motion of said propeller; and

(c) a housing filled with viscous fluid surrounding said propeller.

41. A seismic isolator as recited in claim 40, wherein said coupling between said linear coupling member and said gear drive propeller is provided by a rack-pinion coupling.

42. A seismic isolator as recited in claim 41, wherein said third linear coupling member is configured with multiple pinions for driving multiple gear-driven propellers.

43. A seismic isolator as recited in claim 37 or 38, wherein said damper dissipates energy to reduce the motion of the flexible structure.

44. A seismic isolator as recited in claim 37 or 38, wherein said damper comprises a hydraulic damper.

45. A seismic isolator as recited in claim 37 or 38, wherein said damper comprises a friction damper.

46. A seismic isolator as recited in claim 37 or 38, wherein said damper comprises a viscous elastic damper.

38. A seismic isolator configured for attachment between a rigid structure and a flexible structure to dissipate seismic energy, comprising:

(a) means for mechanically amplifying movement of said flexible structure in relation to the position of said rigid structure, said means for mechanically amplifying movement having a mechanical output; and

(b) a damper coupled to the mechanical output of said means for mechanically amplifying movement;

(c) wherein the means for mechanically amplifying movement comprises

(i) a generally concentric rotating gearset having a first gear attached to a larger second gear;

(ii) said first gear being coupled to a first linear coupling member subject to the motion of the flexible structure in relation to the rigid structure;

(iii) said second gear coupled to a second linear coupling member; and

(iv) said second linear coupling member configured for attachment to said damper.

47. In a seismic isolator configured for attachment within the frame of a civil structure to direct lateral displacement into a damper mechanism, the improvement comprising;

an apparatus configured for mechanically amplifying the displacement of the civil structure and directing said amplified displacement into a damper assembly;

wherein the mechanical amplification apparatus comprises

(i) a rotating gearset having gears of different diameters;

(ii) a small diameter gear within said gearset coupled to a linear coupling member subject to the motion of the flexible structure in relation to rigid structure; and

(iii) a large diameter gear within said gearset which amplifies the motion received by said first gear and couples to a linear coupling member which is received by said damper assembly to dissipate mechanical energy.

49. The improvement as recited in claim 47 or 48, further comprising:

(a) a linear coupling member subject to the movement of the civil structure;

(b) a gear-driven propeller coupled to said linear coupling member and configured to amplify the displacement of the linear coupling member into the rotational motion of said propeller; and

(c) a housing filled with viscous fluid surrounding said propeller.

48. In a seismic isolator configured for attachment within the frame of a civil structure to direct lateral displacement into a damper mechanism the improvement comprising:

an apparatus configured for mechanically amplifying the displacement of the civil structure and directing said amplified displacement into a damper assembly;

the mechanical amplification apparatus comprising;

(a) a rotating gearset having gears of different diameters;

(b) a small diameter gear within said gearset coupled to a linear coupling member subject to the motion of a flexible structure in relation to a rigid structure, and

(c) a large diameter gear within said gearset which amplifies the motion received by said first gear and couples to a linear coupling member which is received by said damper assembly to dissipate mechanical energy;

wherein the coupling between the gears and the linear coupling members comprise rack and pinion mechanisms.