Quantifying necking of rectangular tensile specimens using a mirror-based image analysis system

The cross-sectional area of a neck in a rectangular tensile specimen is not easily measured. In this paper, a technique for accurately quantifying instantaneous necking geometry of rectangular specimens, using a novel mirror setup and high speed camera, is discussed. The technique is non-contact and allows for the sides and front of the specimen to be imaged on one plane with one camera. For this study, a rectangular Sn tensile specimen was tested at 10 s− 1. DIC results and stress–strain behavior measured using the mirror fixture are briefly discussed.

► Novel technique for quantifying necking in multiple sides of a rectangular specimen.
► Technique uses mirror system to capture front and side images of specimen in one frame.
► Technique can be used to quantify local strains by digital image correlation.