Strain amplification sensor

Patent metadata

Field	Value
Publication number	US-9546917-B2
Application number	US-201514669139-A
Country	US
Kind code	B2
Filing date	Mar 26, 2015
Priority date	Mar 26, 2014
Publication date	Jan 17, 2017
Grant date	Jan 17, 2017

Abstract

A strain amplification sensor having a first base portion being coupled to a first member to be strain measured, a second base portion being coupled to a second member to be strain measured, and an amplifying lever system pivotally coupled between the first base portion and the second base portion. The amplifying lever system includes attachment locations that induce opposing relative motion resulting in detectable deflection of the amplifying lever system in response to application of strain between the first base portion and the second base portion.

First claim

What is claimed is:

1. A passive strain sensor comprising:
a first portion being coupled to a first member to be strain measured;
a second portion being coupled to a second member to be strain measured;
at least one arm extending from at said first portion and movable therewith; and
a plurality of step members extending from said second portion, each of said plurality of step members having a different length such that strain between said first portion and said second portion causes said at least one arm to move from one of said plurality of step members to a second of said plurality of step members thereby indicating a magnitude of strain.

2. A strain amplification sensor comprising:
a first portion being coupled to a first member to be strain measured;
a second portion being coupled to a second member to be strain measured; and
a multi-arm system pivotally coupled between said first portion and said second portion, an attachment location of said multi-arm system induces opposing relative motion resulting in detectable deflection of said multi-arm system in response to application of strain between said first portion and said second portion.

3. The strain amplification sensor according to claim 2 wherein said multi-arm system comprises:
a sensor arm extending from said first portion and movable therewith;
a first lever arm pivotally coupled to said sensor arm and pivotable in response to movement of said sensor arm about a first pivot, said first lever arm being pivotally coupled to said second portion via said first pivot;
a second lever arm pivotally coupled to said first lever arm at a first end of said second lever arm and pivotable in response to movement of said first lever arm about a second pivot, said second lever arm being pivotally coupled to said second portion via said second pivot; and
a third lever arm pivotally coupled to said first lever arm and pivotable in response to movement of said first lever arm.

4. The strain amplification sensor according to claim 3 wherein said first lever arm comprises a cam slot, said cam slot receiving a cam extending from said second lever arm.

5. The strain amplification sensor according to claim 3 wherein said second lever arm is pivotally coupled to said first lever arm at said first end at a location relative to said second pivot to result in greater translation of an opposing end of said second lever arm.

6. The strain amplification sensor according to claim 3 wherein an opposing second end of said second lever arm is received within an arcuate slot formed in said third lever arm, a relative position of said second lever arm and said third lever arm providing said detectable deflection of said multi-arm system in response to application of strain between said first portion and said second portion.

7. The strain amplification sensor according to claim 6 , further comprising a marker disposed within said arcuate slot.

8. The strain amplification sensor according to claim 3 , further comprising:
at least one appendage lever extending from said second lever arm for recording said strain.

9. The strain amplification sensor according to claim 2 , further comprising:
a system for recording a maximum experienced strain.

10. The strain amplification sensor according to claim 2 , further comprising:
a system for recording strain time history.

11. The strain amplification sensor according to claim 2 wherein said detectable deflection is visually detectable.

12. The strain amplification sensor according to claim 2 wherein said detectable deflection is electrically detectable.

13. The strain amplification sensor according to claim 2 wherein said detectable deflection is recorded using relative motion of said multi-arm system to propagate a crack or tear.

14. A strain amplification sensor comprising:
a first base portion being coupled to a first member to be strain measured;
a second base portion being coupled to a second member to be strain measured; and
an amplifying lever system pivotally coupled between said first base portion and said second base portion, attachment locations of said amplifying lever system induces opposing relative motion resulting in detectable deflection of said amplifying lever system in response to application of strain between said first base portion and said second base portion, said amplifying lever system having:
a sensor arm extending from said first base portion and movable therewith;
a first lever member pivotally coupled to said sensor arm and pivotable in response to movement of said sensor arm about a first pivot, said first lever member being pivotally coupled to said second base portion via said first pivot;
a second lever member pivotally coupled to said first lever member at a first end of said second lever member and pivotable in response to movement of said first lever member about a second pivot, said second lever member being pivotally coupled to said second base portion via said second pivot; and
a third lever member pivotally coupled to said first lever member and pivotable in response to movement of said first lever member.

15. The strain amplification sensor according to claim 14 wherein said first lever member comprises a cam slot, said cam slot receiving a cam extending from said second lever member.

16. The strain amplification sensor according to claim 14 wherein said second lever member is pivotally coupled to said first lever member at said first end at a location relative to said second pivot to result in greater translation of an opposing end of said second lever member.

17. The strain amplification sensor according to claim 14 wherein an opposing second end of said second lever member is received within an arcuate slot formed in said third lever member, a relative position of said second lever member and said third lever member providing said detectable deflection of said multi-arm system in response to application of strain between said first base portion and said second base portion.

18. The strain amplification sensor according to claim 15 , further comprising a marker disposed within said arcuate slot.

19. The strain amplification sensor according to claim 14 , further comprising:
at least one appendage lever extending from said second lever member for recording said strain.

20. The strain amplification sensor according to claim 14 , further comprising:
a system for recording a maximum experienced strain.

Assignees

• Univ Michigan Regents

Inventors

• Groden Mark D
• Collette Matthew D

Classifications

• G01L1/04 Primary

  by measuring elastic deformation of gauges, e.g. of springs · CPC title

• G01B7/16

  for measuring the deformation in a solid, e.g. by resistance strain gauge · CPC title

• E21B49/00

  Testing the nature of borehole walls; Formation testing; Methods or apparatus for obtaining samples of soil or well fluids, specially adapted to earth drilling or wells · CPC title

• G01B5/30

  for measuring the deformation in a solid, e.g. mechanical strain gauge · CPC title

• G01L1/2206

  Special supports with preselected places to mount the resistance strain gauges; Mounting of supports · CPC title