Test specimen and method of forming and testing the test specimen

Patent metadata

Field	Value
Publication number	US-10488309-B2
Application number	US-201715616286-A
Country	US
Kind code	B2
Filing date	Jun 7, 2017
Priority date	Jun 7, 2017
Publication date	Nov 26, 2019
Grant date	Nov 26, 2019

Abstract

A test specimen is provided. The test specimen includes a coupon. The coupon includes a test portion and grip portions. The grip portions are located on opposite axial ends of the coupon. The test portion is located between the grip portions. The coupon further includes a void extending into the coupon from at least one of the axial ends. The void is defined by a wall having a surface thickness at the test portion that corresponds to a predetermined surface thickness of interest. The coupon is configured to be secured to a test machine for conducting load tests on the coupon.

First claim

What is claimed is:

1. An apparatus comprising:
a first coupon being a product of additive manufacturing and comprising a first void extending from a first axial end of said first coupon, said first void being defined by a first wall having a first surface thickness, said first coupon further comprising a first surface having a first finish;
a second coupon being a product of additive manufacturing and being substantially compositionally identical to said first coupon, said second coupon comprising a second void extending from a second axial end of said second coupon, said second void being defined by a second wall having a second surface thickness that is substantially equal to said first surface thickness, said second coupon further comprising a second surface having a second finish that is different from said first finish; and
a test machine configured to conduct load tests on said first coupon and said second coupon.

2. The apparatus of claim 1 wherein said first coupon and said second coupon are cylindrical.

3. The apparatus of claim 1 wherein:
said first coupon further comprises first grip portions located at opposite axial ends of said first coupon and a first test portion located between said first grip portions; and
said second coupon comprises second grip portions located at opposite axial ends of said second coupon and a second test portion located between said second grip portions.

4. The apparatus of claim 3 wherein said test machine comprises:
a plurality of holders that grip said first grip portions and said second grip portions to secure said first coupon and said second coupon to said test machine;
a test frame;
at least one load assembly; and
a pair of load balancing assemblies that securely retain said first coupon and said second coupon, wherein said load assembly delivers a load to said first coupon and said second coupon by moving at least one of said load balancing assemblies along a single axis.

5. The apparatus of claim 1 wherein the load tests comprise at least one of ASTM E8, ASTM E606, ISO 1143, and ASTM E466 test methods, or any combination of ASTM E8, ASTM E606, ISO 1143, and ASTM E466 test methods.

6. The apparatus of claim 1 wherein the load tests comprise static and fatigue tests.

7. The apparatus of claim 1 wherein said first void is filled with an end plug.

8. A method comprising:
additively manufacturing a first coupon comprising a first void extending from a first axial end of said first coupon, said first void being defined by a first wall having a first surface thickness, said first coupon further comprising a first surface having a first finish;
additively manufacturing a second coupon that is substantially compositionally identical to said first coupon, said second coupon comprising a second void extending from a second axial end of said second coupon, said second void being defined by a second wall having a second surface thickness substantially equal to said first surface thickness, said second coupon further comprising a second surface having a second finish that is different from said first finish;
conducting a first load test on said first coupon to obtain a first load test result;
conducting a second load test on said second coupon to obtain a second load test result; and
comparing said first load test result with said second load test result.

9. The method of claim 8 wherein said first load test and said second load test comprise conducting static and fatigue tests on said first coupon and said second coupon.

10. The method of claim 8 wherein said conducting said first load test comprises using at least one of ASTM E8, ASTM E606, ISO 1143, and ASTM E466 test methods, or any combination of ASTM E8, ASTM E606, ISO 1143, and ASTM E466 test methods.

11. The method of claim 8 wherein said making said first coupon comprises finishing said first surface.

12. The method of claim 8 wherein:
said first coupon comprises first grip portions located at opposite axial ends of said first coupon and a first test portion located between said first grip portions; and
said second coupon comprises second grip portions located at opposite axial ends of said second coupon and a second test portion located between said second grip portions.

13. The method of claim 12 wherein said test machine grips said first grip portions and said second grip portions to secure said first coupon and said second coupon to said test machine.

14. The method of claim 8 further comprising ascertaining, based on said comparing, an impact that surface finish has on mechanical performance.

15. The method of claim 8 wherein:
said making of said first coupon comprises forming said first coupon as a single monolithic piece; and
said making of said second coupon comprises forming said second coupon as a single monolithic piece.

16. The method of claim 8 further comprising inserting a first end plug into said first void.

17. The method of claim 8 wherein said first finish is machined.

18. The method of claim 8 wherein said second finish is as deposited by additive manufacturing.

19. The method of claim 8 further comprising intentionally roughening at least one of said first surface and said second surface.

20. The method of claim 8 wherein at least one of said conducting said first load test and said conducting said second load test is automated.

Assignees

• Boeing Co

Inventors

• Slaughter Victor Blakemore
• Perez Rigoberto

Classifications

• G01N3/28

  Investigating ductility, e.g. suitability of sheet metal for deep-drawing or spinning · CPC title

• G01N3/02 Primary

  Details · CPC title

• G01N3/62

  Manufacturing, calibrating, or repairing devices used in investigations covered by the preceding subgroups · CPC title

• G01N2203/0274

  Tubular or ring-shaped specimens · CPC title

• G01N3/08 Primary

  by applying steady tensile or compressive forces (G01N3/28 takes precedence) · CPC title