| Abstract Scope |
Discontinuous yielding, including the Portevin-Le Chatelier (PLC) effect, introduces a significant challenge in the accurate and repeatable determination of formability characteristics of aluminum and high-strength steels. Measurement of the plastic strain ratio, or r-value, is greatly impacted by small errors in transverse strain, and these advanced materials are known to produce noisy or inconsistent transverse strain data when measured at a single gauge width. Multi-point, averaging transverse strain measurement has been shown to reduce variability in r-value determination by up to 20X and is consistent with common industry standards. Improving the repeatability of formability testing improves a manufacturer's evaluation of their materials, reducing the need for retests and production disruptions. |