Tensile Strength

Tensile Strength (TS)

Ultimate tensile strength (UTS), often shortened to tensile strength (TS) or ultimate strength, is the maximum stress that a material can withstand while being stretched or pulled before failing or breaking. The maximum stress that vulcanized thermoset rubbers and thermoplastic elastomers withstand (strength), before failing, is the ultimate tensile strength.

Importance

Tensile tests are used for controlling product quality, and for determining the effect of chemical or thermal exposure on an elastomer. It is the retention of the elastomer’s physical properties that is most significant, rather than the absolute values of the tensile strength, elongation, or modulus.

Tensile Strength Measurement

Tensile strength is defined as a stress that is measured as force per unit area. Typically, the testing involves taking a small sample with a fixed cross-sectional area, and then pulling it with a tensometer at a constant strain (change in gauge length divided by initial gauge length) rate until the sample breaks.

There are three typical types of tensile strength:

  • Yield strength – The stress a material can withstand without permanent deformation. This is not a sharply defined point. Yield strength is the stress which will cause a permanent deformation of 0.2{65978042ddab827e24d1208ef740965169b89304a6a90a044c13af4b9daa7701} of the original dimension.
  • Ultimate strength – The maximum stress a material can withstand.
  • Breaking strength – The stress coordinate on the stress-strain curve at the point of rupture.

The tensile strength (ASTM D412-98a) of a material is determined using one of two testing methods, that do not always produce identical results:

Test Method A

Dumbbell and Straight Section Specimens – the test specimens are injection molded or cut from a flat sheet not less than 1.3 mm (0.05 inch) nor more than 3.3 mm (0.13 inch).

Test Method B

Cut Ring Specimens – test specimens are produced by cutting rings from sheets or tubing. In both cases dimensions, etc. are defined by the ASTM specifications.

Calculating Tensile Strength

Calculating TS for a material is accomplished using:

TS = F(BE)/A)

where:

  • TS = tensile strength, the stress at rupture, MPa (lbf/in.2)
  • F(BE) = the force magnitude at rupture, MN (lbf)
  • A = cross-sectional area of unstrained specimen, m2(in.2)
Techno Ad is your comprehensive supplier for all sealing solutions
CONTACT US