US 5,798,463 A · Self-contained constant stress/constant strain test fixture

Abstract

A tensile test fixture for applying constant tensile forces to a tensile test specimen comprises two mounting grips, each mounted to one of two lever arms in a pivoted lever arm frame structure. One end of each lever arm is pivotally attached to a compression column while the other end of each lever arm is attached to one end of a force-applying assembly. The mounting grips are pivotally attached to their respective lever arms between the compression column and the force-applying assembly and are designed to hold opposite ends of a tensile test specimen. The force-applying assembly comprises stress and strain modules that are interchangeably installable into the force-applying assembly to selectively subject tensile test specimens to constant strain and constant stress.

Claims16

Dependent claims

A method for selectively subjecting tensile test specimens to constant stress and constant strain using a single test fixture comprising a frame supporting first and second mounting grips and a force-applying assembly comprising a strain module connectable between said first and second mounting grips to subject tensile test specimens to constant strain, said force-applying assembly additionally comprising a stress module interchangeably connectable between said first and second mounting grips in place of said strain module to subject tensile test specimens to constant stress, said method comprising the steps of:

constructing the test fixture;
installing one of the stress module and strain module;
attaching a tensile test specimen to the mounting grips;
adjusting the force-applying assembly;
placing the specimen and tensile test fixture in a desired test environment for a desired test period;
detaching the test specimen from the mounting grips;
removing the installed module;
installing the other of the modules to the frame;
attaching a second test specimen to the mounting grips ;
and
adjusting the force-applying assembly.

8 more elements

A tensile test fixture for applying constant tensile forces to a tensile test specimen, said test fixture comprising:

first and second mounting grips for holding opposite ends of a tensile test specimen;
a frame supporting said first and second mounting grips for relative reciprocal movement toward and away from one another;
and
a force-applying assembly comprising a strain module connectable between said first and second mounting grips to subject tensile test specimens to constant strain;
said force-applying assembly additionally comprising a stress module connectable between said first and second mounting grips to subject tensile test specimens to constant stress;
and
said stress module and said strain module are interchangeably connectable within said force-applying assembly.

4 more elements

A tensile test fixture for applying constant tensile forces to a tensile specimen, said test fixture comprising:

first and second mounting grips for holding opposite ends of a tensile test specimen;
a frame supporting said first and second mounting grips for relative reciprocal movement toward and away from one another;
said frame comprising a pivoted lever arm structure including first and second lever arms connected to a compression column at first and second compression column connecting points and extending transversely to respective first and second force-application points, at least one of said lever arms being pivotally connected to said compression column, said first and second mounting grips supported on said first and second lever arms, respectively, said first mounting grip disposed between said first compression connecting point and said first force-application point and said second mounting grip disposed between said second compression connecting point and said second force-application point, and
a force-applying assembly including first and second opposite ends connected to said first and second lever arm force-application points, respectively;
and
said force-applying apparatus including interchangeable strain and stress modules.

3 more elements

Dependencies are inferred from the claim text.

Self-contained constant stress/constant strain test fixture

Life of this patent

Self-contained constant stress/constant strain test fixture

Life of this patent

Abstract

Claims16