Stainless Steel Tubing, Advanced Video Extensometers, Tensile Testing

Stainless steel tubing (or any other variety of rigid metallic tubing) can be difficult to test in tension for two reasons. The first is that standard methods of gripping will cause the tubing to collapse and lead to pre-mature failure of the specimen. The second is strain measurement is usually not possible with traditional clip-on extensometers since the knife-edges lead to high-stress concentrations and consequently failure of the thin specimen wall.

Instron’s Advanced Video Extensometer 2 (AVE2) allows for strain measurement without the use of contact points, thus avoiding premature failure on thin-walled specimens. Marking specimens is quick and easy, and simplifies the workflow.

The challenges of testing to this standard are:

• Specimen geometry and gripping
• Strain measurement

Instron's Solution:

• Instron has a number of solutions that are well suited to gripping tubular specimens, including wedge grips with serrated vee faces.
• Instron’s Advanced Video Extensometer 2 (AVE 2) is well-suited to measure strain on a pipe or tube section instead of using traditional clip-on extensometry.

It is important to review the pertinent testing standards in order to fully understand the test setup, procedure, and results requirements.