Development of a Full-Field Digital Stress Gradient Sensor for Failure Characterization of Transparent Structural Materials

Auburn University, Auburn AL

Investigators

Abstract

The research objective of this award is to develop a full-field, non-contact, optical technique to quantify angular deflections of light rays caused by non-uniform stress fields in optically transparent solids. The method exploits the elasto-optic effect in concurrence with the digital image correlation methodology to extract orthogonal stress gradients in transparent solids. The feasibility of the method to study failure behavior of solids under quasi-static and high strain rate loading conditions will be demonstrated using visible and near infrared radiation. The successful development of this new method will provide a powerful, complementary measurement tool for experimental solid mechanics. Optical transparency is a common characteristic of solids used in many engineering applications including electronic displays, automotive windshields, aircraft windows and canopies, hurricane resistant windows, and helmet visors. This research contributes towards understanding failure mechanics of such materials under quasi-static and stress wave loading conditions. Education and training of undergraduate and graduate students in interdisciplinary areas of optical metrology and mechanical characterization of structural materials is integral to this research. Findings from this research will be displayed during annual undergraduate and graduate recruitment events to attract K-12 and underrepresented students to engineering. The findings will also be integrated into graduate courses taught by the PI and disseminated through archival journals and conference publications.