Thomas C Morris

US Patent:

46761101, Jun 30, 1987

Filed:

Jul 16, 1986

Appl. No.:

6/886121

Inventors:

James D. Hodo - Huntsville AL
Dennis R. Moore - Huntsville AL
Thomas F. Morris - Huntsville AL
Newton G. Tiller - Athens AL

Assignee:

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

International Classification:

G01N 332

US Classification:

73809

Abstract:

A fatigue testing apparatus (10) for simultaneously subjecting a plurality of material test specimens (24) to cyclical tension loading to determine the fatigue strength of the material. The fatigue testing apparatus includes a pulling head (12) having cylinders (26) defined therein which carry reciprocating pistons (32). The reciprocation of the pistons is determined by cyclical supplies of pressurized fluid to the cylinders. Piston rods (18) extend from the pistons through the pulling head and are attachable to one end of test specimens, the other end of the test specimens being attachable to a fixed base (38), causing test specimens attached between the piston rods and the base to be subjected to cyclical tension loading. Because all of the cylinders share a common pressurized fluid supply, the breaking of a test specimen does not substantially affect the pressure of the fluid supplied to the other cylinders nor the tension applied to the other test specimens.