As the dumbbell specimen of LCE goes through a polydomain monodomain transition, its gage length becomes monodomain while its ends remain in the polydomain (softer) state. As a consequence, the strain is not homogeneous anymore during the uniaxial stretching and the heads of the specimen rather than the gage length tend to stretch and accommodate the imposed strain.

Here is the trick. The basic tensile procedure described in the MTS manual on this wiki still applies but some precautions should be taken regarding the placement of the specimen in the grips. Use the Advantage Screw Action Tensile grips.

1. Measure as precisely as possible the gage length and mark with a sharpie its limits on the specimen. Measure also the width and thickness as needed for any tensile test.

2. Measure the length of a small piece of metal (the calibration rectangular pieces of the DMA are perfect for that) and place the grips at that distance from each other using the manual commands.

3. Zero the displacement in the software.

4. Place the specimen in the grips making sure that the limits of the gage length are at the border the grips (almost in).

5. Now move the grips slowly until the specimen is taut. You should be at the same distance than the gage length of the specimen you measured. You can check by adding the displacement value (read on the computer) to the length of the small piece of metal you first used to set the grips. If you are under the gage length, you will create stress concentrations by pulling on a rectangular specimen with no heads. If you are over, the heads will stretch once the transition is passed.

6. Perform the test as you would any uniaxial tensile test.

Note: this method ensures that you are applying the strain as much as possible on the gage length. It is still definitely not perfect. One way of checking the strain applied to the gage length would be to perform a test with an extensometer on the specimen or with DIC.