| About this Abstract |
| Meeting |
2020 TMS Annual Meeting & Exhibition
|
| Symposium
|
Understanding and Predicting Dynamic Behavior of Materials
|
| Presentation Title |
Informing Flow Stress Models at High Strain-rates Through In-situ Imaging of Hole Closure under Dynamic Compression |
| Author(s) |
Jonathan Lind, A.K. Robinson, M. Nelms, Nathan Barton, Mukul Kumar |
| On-Site Speaker (Planned) |
Jonathan Lind |
| Abstract Scope |
The stress at which a material plastically flows depends on the current state of the material, strain-rate, and microstructure among other quantities. Experimental tests at high strain-rates (>103/s) often use measurement of shape change to infer flow stress behavior. Given stress and strain heterogeneities, inferences about flow stress behavior from those observations are facilitated by comparisons with advanced simulations. A new plate-impact experimental test will be described consisting of in-situ x-ray imaging to observe the closure of a cylindrical hole in a sample during the passage of a pressure pulse of controlled amplitude and duration. The rate of hole closure and final hole size are measured through time via multi-frame imaging. The goal being to provide high fidelity data to inform flow stress models at high strain-rates and large strains. We will present experiments on copper that aim to examine the role of starting microstructure. The experimental observations will be compared against predictions from direct numerical simulations using several flow stress models. We will discuss the results, the sensitivity of this new experimental test, and a path forward to informing the models under conditions where data is currently sparse. |
| Proceedings Inclusion? |
Undecided |