John L Crews

US Patent:

47182814, Jan 12, 1988

Filed:

Feb 12, 1987

Appl. No.:

7/013802

Inventors:

John H. Crews - Grafton VA

Assignee:

The United States of America as represented by the Administrator,
National Aeronautics & Space Administration - Washington DC

International Classification:

G01N 336

US Classification:

73794

Abstract:

A material specimen 12 containing a central hole is bolted (bolt 27) between two bearing guide plates 28 and 29. An applied load control 11 applies an applied load, either tension or compression, to one end of specimen 12 and a bypass load control 13 applies a bypass load to the other end of specimen 12. Both load controls have their control inputs supplied by a single input signal generator 24. The difference between the applied load and the bypass load is transmitted through bolt 27 and plates 28 and 29 to bearing load cells 30 and 31.

US Patent:

49266942, May 22, 1990

Filed:

Jul 28, 1989

Appl. No.:

7/386172

Inventors:

John H. Crews - Grafton VA
James R. Reeder - Hampton VA

Assignee:

The United States of America as represented by the United States
National Aeronautics and Space Administration - Washington DC

International Classification:

G01N 300

US Classification:

73794

Abstract:

A delamination test apparatus and method uses a single beam to simultaneously apply opening and shear stresses to a test specimen. A fulcrum extending downwardly from the beam produces shear stress in the specimen by downward movement, and opening stress by pivotal upward movement of the beam, which results by virtue of the fact that the applied load is on one side of the fulcrum while the test specimen is connected to the beam on the opposite side of the fulcrum.