Material testing machine, test piece attachment set for the material testing machine, and method of conducting a material test with the material testing machine

• US 6,389,876 B1
• Filed: 06/16/2000
• Issued: 05/21/2002
• Est. Priority Date: 06/18/1999
• Status: Expired due to Term

• Current Assignee: Kabushiki Kaisha Saginomiya Seisakusho, Shinji Tanimura, United States Filter Corporation (Siemens AG)
• Original Assignee: Kabushiki Kaisha Saginomiya Seisakusho, Shinji Tanimura
• Inventors: Yin, Rongsheng, Tanimura, Shinji, Takada, Susumu
• Primary Examiner(s): Fuller, Benjamin R.
• Assistant Examiner(s): ALLEN, ANDRE J
• Application Number:
  US09/595,174
• Time in Patent Office: 704 Days
• Field of Search: 737/74, 737/89, 737/90, 737/94, 73/120.1, 73/120.4, 73/120.9
• US Class Current: 73/12.01
• CPC Class Codes: G01N 2203/001 Impulsive
• CPC Class Codes: G01N 2203/0016 Tensile or compressive
• CPC Class Codes: G01N 3/06 Special adaptations of indicating or recording means
• CPC Class Codes: G01N 3/303 generated only by free-falling weight

Abstract

A material testing machine has a movable, load applying block and a fixed, load sensing block. The load sensing block has a body with sufficient volume and mass and a small sensing projection provided on the body. The sensing projection is much smaller than the body and has a side surface on which strain gages are affixed. A test piece is installed to the material sensing projection such that any load applied to the test piece may be transmitted to the sensing projection to cause a corresponding strain of the sensing projection. Any strain of the sensing projection, which may be either static strain or dynamic strain, can be determined from the outputs of the strain gages. The determined strain of the sensing projection is used to derive the load transmitted to the sensing projection and thus the load applied to the test piece.

Claims

1. A material testing machine having a frame, load applying means for applying a load in a predetermined direction to a test piece and load measuring means for sensing a load applied to the test piece, said material testing machine comprising:

(a) said load measuring means comprising a load sensing block having (a-1) a body with sufficient volume and mass and (a-2) at least one sensing projection which is sufficiently smaller than said body of said load sensing block and which has (i) a distal end, (ii) a proximal end connected to said body of said load sensing block, (iii) a longitudinal axis extending in said predetermined direction and (iv) a side surface;

(b) said load measuring means further comprising (b-1) a plurality of strain gages affixed on said side surface of said sensing projection and (b-2) processing means for processing outputs of said strain gages to determine a load acting on said sensing projection;

(c) said load sensing block being arranged such that a stress wave produced in said sensing projection by an impact acting on said distal end of said sensing projection can propagate along said longitudinal axis of said sensing projection from said distal end to said proximal end and that a first part of an energy of the stress wave reaching said proximal end can further propagate into said body of said load sensing block to reach peripheral surfaces of said body and reflect again and again from one peripheral surface to another so that the stress wave in said body will finally decades out to lose dynamic behavior thereof;

(d) said load sensing block being arranged such that a second part of the energy of the stress wave reaching said proximal end can be reflected at said proximal end to return back to said distal end to create shuttling echoes of the stress wave between said distal and proximal ends and that said sensing projection has a sufficiently short length so that said shuttling echoes has a turnaround time sufficiently shorter than a duration of the impact applied to said distal end so as to prevent dynamic behavior of said sensing projection due to the stress wave from substantially effecting on the measurement provided by said load measuring means;

(e) said load measuring means being capable of measurement of static and quasi-static loads with accuracy by using said strain gages to sense any static and quasi-static strains of said sensing projection produced by static and quasi-static loads applied to said distal end of said sensing projection and of measurement of impact loads with accuracy by using said strain gages to sense any dynamic strains of said sensing projection produced by dynamic loads applied to said distal end of said sensing projection;

(f) said load applying means comprising (i) a load applying block, (ii) guide means for guiding said load applying block for movement in said predetermined direction, (iii) drive means for driving said load applying block in said predetermined direction and (iv) control means for controlling said driving means; and

(g) said material testing machine being capable of installation of the test piece thereto such that any loads applied by said load applying block to the test piece can be transmitted to said distal end of said sensing projection.

2. A material testing machine according to claim 1, further comprising:

(h) said load applying block having (h-1) a body with sufficient volume and mass and (h-2) at least one load applying projection projecting from said body of said load applying block, said load applying block being arranged such that a stress wave produced in said load applying projection by an impact acting thereon may propagate into said body of said load applying block to reach peripheral surfaces of said body and reflect again and again from one peripheral surface to another, so as to prevent dynamic behavior of said load applying block due to the stress wave from substantially effecting on a load applied to the test piece.

3. A material testing machine according to claim 1, further comprising:

(i) test-piece-strain measuring means for measuring a strain of the test piece produced by a load applied to the test piece.

4. A material testing machine according to claim 1, wherein:

said drive means is capable of accelerating said load applying block to a desired velocity and causing a collision of said load applying block against the test piece to thereby apply an impact load to the test piece, so as to permit material tests at relatively high strain rates.

5. A material testing machine according to claim 4, wherein:

said drive means is capable of displacing said load applying block in said predetermined direction at a controlled, relatively low velocity as controlled by said control means, so as to permit material tests at relatively low strain rates.

6. A material testing machine according to claim 4, wherein:

said control means controls a magnitude of a load, and

said drive means is capable of urging said load applying block in said predetermined direction such that the load having a controlled magnitude may be applied by said load applying block to said test piece, so as to permit material tests using static and quasi-static loads.

7. A material testing machine according to claim 5, wherein:

said control means controls a magnitude of a load, and

said drive means is capable of urging said load applying block in said predetermined direction such that the load having a controlled magnitude may be applied by said load applying block to said test piece, so as to permit material tests using static and quasi-static loads.

8. A material testing machine according to 1, wherein:

said predetermined direction is vertical direction;

said control means controls a vertical position of said load applying block;

said driving means comprises lift means for lifting up/down said load applying block and position measuring means for measuring vertical position of said load applying block; and

said driving means is capable of subjecting said load applying block to a free fall from a controlled vertical position and causing a collision of said load applying block against the test piece to thereby apply an impact load to the test piece, so as to permit material tests at relatively high strain rates.

9. A material testing machine according to claim 8, wherein:

said lift means is capable of lifting up/down said load applying block at a controlled, relatively low velocity as controlled by said control means, so as to permit material tests at relatively low strain rates.

10. A material testing machine according to claim 8, wherein:

said control means controls a magnitude of a load, and

said lift means is capable of urging said load applying block in vertical direction such that the load having a controlled magnitude may be applied by said load applying block to said test piece, so as to permit material tests using static and quasi-static loads.

11. A material testing machine according to claim 8, wherein:

said control means controls a magnitude of load, and

said lift means is capable of urging said load applying block in vertical direction such that the load having a controlled magnitude may be applied by said load applying block to said test piece, so as to permit material tests using static and quasi-static loads.

12. A material testing machine according to claim 1, wherein:

said predetermined direction is vertical direction;

said load applying block is disposed above said load sensing block;

said load sensing block has a top surface facing said load applying block and having a pair of said sensing projections formed thereon;

said load sensing block has a receptacle formed in said top surface between said pair of sensing projections, for receiving the test piece having test piece attachments connected thereto;

said pair of sensing projections are capable of placement thereon of a test piece attachment connected to the test piece for installation of the test piece to said material testing machine.

13. A material testing machine according to claim 12, wherein:

said load applying block has a bottom surface having a pair of load applying projections; and

said load applying projections having respective distal ends capable of contact with another test piece attachment connected to the test piece in order to apply a load to the test piece.

14. A material testing machine according to claim 12, wherein:

said load applying block has a bottom surface having a load applying area defined at the center thereof; and

said load applying area is capable of contact with a second test piece attachment connected to the test piece in order to apply a load to the test piece.

15. A material testing machine according to claim 1, wherein:

said load sensing block has a side ridge protruding in transverse direction with respect to said predetermined direction from said body of said load sensing block;

said side ridge has an end surface extending in transverse direction with respect to said predetermined direction;

said load sensing block has said sensing projection provided on said end surface; and

said sensing projection has a connecting portion at said distal end thereof for connection with the test piece.

16. A material testing machine according to claim 15, wherein:

said connecting portion of said sensing projection is capable of direct connection with the test piece.

17. A material testing machine according to claim 15, wherein:

said connecting portion of said sensing projection is capable of connection with a test piece attachment which is connected with the test piece, for indirect connection with the test piece.

18. A material testing machine according to claim 15, wherein:

said guide means is so arranged as to guide said load applying block such that said load applying block passes by said load sensing block along one side of said load sensing block and close to said side ridge; and

said load applying block has an engaging portion for engagement with a test piece attachment connected to one end of the test piece having the other end thereof connected to said connecting portion of said sensing projection, for applying a load to the test piece.

19. A material testing machine according to claim 15, wherein:

said guide means is so arranged as to guide said load applying block such that said load applying block passes by said load sensing block along one side of said load sensing block and close to said side ridge; and

said load applying block has a pair of side protrusions protruding in transverse direction with respect to said predetermined direction from said body of said load applying block, said pair of side protrusions serving as engaging portions for engagement with a test piece attachment connected to one end of the test piece having the other end thereof connected to said connecting portion of said sensing projection, for applying a load to the test piece.

20. A material testing machine according to claim 19, wherein:

said side ridge extends in said predetermined direction and has a substantially fixed cross section and opposite sides;

said guide means is so arranged as to guide said load applying block such that said pair of side protrusions of said load applying block pass by said side ridge close to and along said opposite sides of said side ridge.

21. A material testing machine according to claim 15, wherein:

said guide means is so arranged as to guide said load applying block such that said load applying block passes by said load sensing block along one side of said load sensing block and close to said side ridge; and

said load applying block has an engaging portion for engagement with one end of the test piece having another end thereof connected to said connecting portion of said sensing projection, for applying a load to the test piece.

22. A material testing machine according to claim 15, wherein:

said guide means is so arranged as to guide said load applying block such that said load applying block passes by said load sensing block along one side of said load sensing block and close to said side ridge; and

said load applying block has a pair of side protrusions protruding in transverse direction with respect to said predetermined direction from said body of said load applying block, said pair of side protrusions serving as engaging portions for engagement with one end of the test piece having another end thereof connected to said connecting portion of said sensing projection, for applying a load to the test piece.

23. A material testing machine according to claim 22, wherein:

said side ridge extends in said predetermined direction and has a substantially fixed cross section and opposite sides;

said guide means is so arranged as to guide said load applying block such that said pair of side protrusions of said load applying block pass by said side ridge close to and along said opposite sides of said side ridge.

24. A material testing machine according to claim 1 wherein:

said load sensing block has a side ridge protruding in transverse direction with respect to said predetermined direction from said body of said load sensing block;

said side ridge has opposite end surfaces extending in transverse direction with respect to said predetermined direction;

said load sensing block has two said sensing projections one provided on each of said opposite end surfaces;

at least one of said sensing projections has a connecting portion at said distal end thereof for connection with the test piece;

said guide means is so arranged as to guide said load applying block such that said load applying block passes by said load sensing block along one side of said load sensing block and close to said side ridge; and

said load applying block has an engaging portion for engagement with a test piece attachment connected to one end of the test piece having another end thereof connected to said connecting portion of said sensing projection, for applying a load to the test piece.

25. A material testing machine according to claim 1, wherein:

said load sensing block has a side ridge protruding in transverse direction with respect to said predetermined direction from said body of said load sensing block;

said side ridge has opposite end surfaces extending in transverse direction with respect to said predetermined direction;

said load sensing block has two said sensing projections one provided on each of said opposite end surfaces;

at least one of said sensing projections has a connecting portion at said distal end thereof for connection with the test piece;

said guide means is so arranged as to guide said load applying block such that said load applying block passes by said load sensing block along one side of said load sensing block and close to said side ridge; and

said load applying block has a pair of side protrusions protruding in transverse direction with respect to said predetermined direction from said body of said load applying block, said pair of side protrusions serving as engaging portions for engagement with a test piece attachment connected to one end of the test piece having another end thereof connected to said connecting portion of said sensing projection, for applying a load to the test piece.

26. A material testing machine according to claim 25, wherein:

said side ridge extends in said predetermined direction and has a substantially fixed cross section and opposite sides;

said guide means is so arranged as to guide said load applying block such that said pair of side protrusions of said load applying block pass by said side ridge close to and along said opposite sides of said side ridge.

27. A material testing machine according to claim 1, wherein:

said load sensing block has a side ridge protruding in transverse direction with respect to said predetermined direction from said body of said load sensing block;

said side ridge has opposite end surfaces extending in transverse direction with respect to said predetermined direction;

said load sensing block has two said sensing projections one provided on each of said opposite end surfaces;

at least one of said sensing projections has a connecting portion at said distal end thereof for connection with the test piece;

said guide means is so arranged as to guide said load applying block such that said load applying block passes by said load sensing block along one side of said load sensing block and close to said side ridge; and

said load applying block has an engaging portion of engagement with one end of the test piece having another end thereof connected to said connecting portion of said sensing projection, for applying a load to the test piece.

28. A material testing machine according to claim 1, wherein:

said load sensing block has a side ridge protruding in transverse direction with respect to said predetermined direction from said body of said load sensing block;

said side ridge has opposite end surfaces extending in transverse direction with respect to said predetermined direction;

said load sensing block has two said sensing projections one provided on each of said opposite end surfaces;

at least one of said sensing projections has a connecting portion at said distal end thereof for connection with the test piece;

said guide means is so arranged at to guide said load applying block such that said load applying block passes by said load sensing block along one side of said load sensing block and close to said side ridge; and

said load applying block has a pair of side protrusions protruding in transverse direction with respect to said predetermined direction from said body of said load applying block, said pair of side protrusions serving as engaging portions for engagement with one end of the test piece having the other end thereof connected to said connecting portion of said sensing projection, for applying a load to the test piece.

29. A material testing machine according to claim 28, wherein:

said side ridge extends in said predetermined direction and has a substantially fixed cross section and opposite sides;

said means is so arranged as to guide said load applying block such that said pair of side protrusions of said load applying block pass by said side ridge close to and along said opposite sides of said side ridge.

30. A material testing machine according to claim 1, wherein:

said predetermined direction is vertical direction;

said load sensing block has a side ridge protruding in transverse direction with respect to vertical direction from said body of said load sensing block;

said side ridge has an end surface extending in transverse direction with respect to vertical direction and facing downward;

said load sensing block has said sensing projection provided on said end surface;

said distal end of said sensing projection facing downward; and

said sensing projection has a connecting portion at said distal end thereof for connection with the test piece.

31. A material testing machine according to claim 30, wherein:

said connecting portion of said sensing projection is capable of direct connection with the test piece.

32. A material testing machine according to claim 30, wherein:

said connecting portion of said sensing projection is capable of connection with a test piece attachment which is connected with the test piece, for indirect connection with the test piece.

33. A material testing machine according to claim 30, wherein:

said guide means is so arranged as to guide said load applying block such that said load applying block passes by said load sensing block along one side of said load sensing block and close to said side ridge; and

said load applying block has an engaging portion for engagement with a test piece attachment connected to one end of the test piece having another end thereof connected to said connecting portion of said sensing projection, for applying a load to the test piece.

34. A material testing machine according to claim 30, wherein:

said guide means is so arranged as to guide said load applying block such that said load applying block passes by said load sensing block along one side of said load sensing block and close to said side ridge; and

said load applying block has a pair of side protrusions protruding in transverse direction with respect to vertical direction from said body of said load applying block, said pair of side protrusions serving as engaging portions for engagement with a test piece attachment connected to one end of the test piece having the other end thereof connected to said connecting portion of said sensing projection, for applying a load to the test piece.

35. A material testing machine according to claim 34, wherein:

said side ridge extends in vertical direction and has a substantially fixed cross section and opposite sides;

said guide means is so arranged as to guide said load applying block such that said pair of side protrusions of said load applying block pass by said side ridge close to and along said opposite sides of said side ridge.

36. A material testing machine according to claim 30, wherein:

said guide means is so arranged as to guide said load applying block such that said load applying block passes by said load sensing block along one side of said load sensing block and close to said side ridge; and

said load applying block has an engaging portion for engagement with one end of the test piece having the other end thereof connected to said connecting portion of said sensing projection, for applying a load to the test piece.

37. A material testing machine according to claim 30, wherein:

said guide means is so arranged as to guide said load applying block such that said load applying block passes by said load sensing block along one said of said load sensing block and close to said side ridge; and

said load applying block has a pair of side protrusions protruding in transverse direction with respect to vertical direction from said body of said load applying block, said pair of side protrusions serving as engaging portions for engagement with one end of the test piece having another end thereof connected to said connecting portion of said sensing projection, for applying a lead to the test piece.

38. A material testing machine according to claim 37, wherein:

said side ridge extends in vertical direction and has a substantially fixed cross section and opposite sides;

said guide means is so arranged as to guide said load applying block such that said pair of side protrusions of said load applying block pass by said side ridge close to and along said opposite sides of said side ridge.

39. A material testing machine according to claim 30, wherein:

said driving means comprises lift means for lifting up/down said load applying block and position measuring means for measuring vertical position of said load applying block;

said driving means is capable of subjecting said load applying block to a free fall from a controlled vertical position as controlled by said control means and causing a collision of said load applying block against the test piece to thereby apply an impact load to the test piece, so as to permit material tests at relatively high strain rates.

40. A material testing machine according to claim 39, wherein:

said lift means is capable of lifting up/down said load applying block at a controlled, relatively low velocity as controlled by said control means, so as to permit material tests at relatively low strain rates.

41. A material testing machine according to claim 39, wherein;

said lift means is capable of urging said load applying block in vertical direction such that a load of a controlled magnitude as controlled by said control means may be applied by said load applying block to said test piece, so as to permit material tests using static and quasi-static loads.

42. A test piece attachment set used for installation of a test piece to a material testing machine according to claim 12 for conducting a tensile test, the test piece having first and second ends to be directed toward said load applying block and said load sensing block, respectively, when the test piece is installed to said material testing machine, said test piece attachment set comprising:

(a) first and second test piece attachments for connection to said first and second end of the test piece, respectively;

(b) said first test piece attachment being adapted for placement on said distal ends of said pair of sensing projections while connected to said first end of the test piece; and

(c) said second test piece attachment being adapted for engagement with said load applying block while connected to said second end of the test piece;

(d) wherein application of a compressive load by said load applying block to said second test piece attachment results in application of a tensile load between said first and second ends of the test piece.

43. A test piece attachment set according to claim 42, wherein:

said first test piece attachment comprises an elongated bar-like member having a connecting portion at a center thereof for connection to said first end of the test piece.

44. A test piece attachment set used for installation of a test piece to a material testing machine according to claim 13 for conducting a tensile test, the test piece having first and second ends to be directed toward said load applying block and said load sensing block, respectively, when the test piece is installed to said material testing machine, said test piece attachment set comprising:

(a) first and second test piece attachments for connection to said first and second end of the test piece, respectively;

(b) said first test piece attachment being adapted for placement on said distal ends of said pair of sensing projections while connected to said first end of the test piece;

(c) said second test piece attachment being adapted for engagement with said load applying block while connected to said second end of the test piece;

(d) said first test piece attachment comprising an elongated bar-like member having opposite ends adapted for placement on said distal ends of said pair of sensing projections and a connecting portion at a center thereof for connection to said first end of the test piece; and

(e) said second test piece attachment comprising an elongated bar-like member having opposite ends adapted for engagement with said distal ends of said pair of load applying projections to receive a load therefrom and a connecting portion at the center thereof for connection to said second end of the test piece;

(f) wherein application of a compressive load by said load applying block to said second test piece attachment results in application of a tensile load between said first and second ends of the test piece.

45. A test piece attachment set used for installation of a test piece to a material testing machine according to claim 14 for conducting a tensile test, the test piece having first and second ends to be directed toward said load applying bock and said load sensing block, respectively, when the test piece is installed to said material testing machine, said test piece attachment set comprising:

(a) first and second test piece attachments for connection to said first and second end of the test piece, respectively;

(b) said first test piece attachment being adapted for placement on said distal ends of said pair of sensing projections while connected to said first end of the test piece;

(c) said second test piece attachment being adapted for engagement with said load applying block while connected to said second end of the test piece;

(d) said first test piece attachment comprising an elongated bar-like member having opposite ends adapted for placement on said distal ends of said pair of sensing projections and a connecting portion at a center thereof for connection to said first end of the test piece; and

(e) said second test piece attachment comprising a rectangular ring-shaped member having an upper side adapted for engagement with said load applying area of said load applying block to receive a load therefrom and a lower side with a connecting portion at the center thereof for connection to said second end of the test piece;

(f) wherein application of a compressive load by said load applying block to said second test piece attachment results in application of a tensile load between said first and second ends of the test piece.

46. A test piece attachment set according to claim 45, wherein:

said upper side of said second test piece attachment has a top surface on which a cushion layer is affixed to receive a load from said load applying area of said load applying block.

47. A method of conducting a material test with a material testing machine according to claim 15, comprising the steps of:

(a) providing a test piece having first and second ends and an axis and being adapted for a tensile test conducted with a tensile load applied along said axis between said first and second ends;

(b) connecting said first end of said test piece to said connecting portion at said distal end of said sensing projection, such that said axis extends in said predetermined direction;

(c) connecting said second end of said test piece to a test piece attachment; and

(d) driving said load applying block in direction from said first end to said second end of said test piece, so as to apply a load from said load applying block to said test piece attachment connected to said second end of said test piece.

48. The method according to claim 47, wherein:

said step of driving said load applying block comprises driving said load applying block at a velocity that produces a strain of said test piece at relatively high strain rate.

49. The method according to claim 47, wherein:

said step of driving said load applying block comprises driving said load applying block at a velocity that produces a strain of said test piece at relatively low strain rate.

50. A method of conducting a material test with a material testing machine according to claim 15, comprising the steps of:

(a) providing a test piece having first and second connecting portions and being adapted for a material test conducted with a load applied between said first and second ends;

(b) connecting said first connecting portion of said test piece to said connecting portion at said distal end of said sensing projection;

(c) connecting said second end of said test piece to a test piece attachment; and

(d) driving said load applying block so as to apply a load from said load applying block to said test piece attachment connected to said second end of said test piece.

51. The method according to claim 50, wherein:

said step of driving said load applying block comprises driving said load applying block at a velocity that produces a strain of said test piece at relatively high strain rate.

52. The method according to claim 50, wherein:

said step of driving said load applying block comprises driving said load applying block at a velocity that produces a strain of said test piece at relatively low strain rate.

53. A method of conducting a material test with a material testing machine according to claim 15, comprising the steps of:

(a) providing a test piece having first and second ends, said test piece further having a connecting portion and an engaging portion at said first end second ends, respectively, said test piece being adapted for a material test conducted with a load applied between said connecting portion and said engaging portion;

(b) connecting said connecting portion of said test piece to said connecting portion at said distal end of said sensing projection;

(c) driving said load applying block so as to apply a load from said load applying block to engaging portion of said test piece.

54. The method according to claim 53, wherein:

said step of driving said load applying block comprises driving said load applying block at a velocity that produces a strain of said test piece at relatively high strain rate.

55. The method according to claim 53, wherein:

said step of driving said load applying block comprises driving said load applying block at a velocity that produces a strain of said test piece at relatively low strain rate.