Iosipescu Gage

[YoungTurk]

We're performing Iosipescu ASTM D 5379 shear lab tests and using foil gages to measure the shear strain. Vishay makes a custom gage for the application, but we had some difficulty with results, lead time and cost.

http://www.vishaypg.com/docs/11525/shearpat.pdf

Can anyone provide alternative options or suggestions for how to accomplish shear strain measurements for this test? I'm especially interested if there is a standard lab method which doesn't rely on custom gages that maybe we're missing.

Thanks!

 

[mmhaynes]

Those are really long gages for that test. We always run either the EA-06-062TH-350 or SK-06-062TV-350 patterns depending on whether its at room temp or cryogenic temps. The biggest key with these little guys is to get them lined up just so before bonding them down.
Mark the specimens carefully after prepping, I use a 6" X 0.5" scale and always mark to the same side of the mark, then stick the gage to the tape, line up the gage with the marks and stick the tape at one end. Now you can peel back the tape and gage, apply the adhesive, clamp and cure.
Remember that a 1° delta in alignment can result in around 5% error in results.
HTH


Mark Haynes
Senior Engineer
Composite Technology Development

 

[TheBigM]

You could try Micro-Flexitronics (

http://www.mflstraingauges.com/).

They offer a large variety of strain gauges and also will make them to your requirements if needs be. They're cheaper than VPG and delivery is usually less than two weeks.
You'll still need to get your adhesives from VPG though.

M