Evaluation of stress–strain curve estimates in dynamic experiments.pdf

International Journal of Impact Engineering 37 (2010) 161–169 Contents lists available at ScienceDirect International Journal of Impact Engineering journal homepage: /locate/ijimpeng Evaluation of stress–strain curve estimates in dynamic experiments a, b, * ´ a a, c Dirk Mohr , Gerard Gary , Bengt Lundberg a ´ Solid Mechanics Laboratory (CNRS-UMR 7649), Ecole Polytechnique, 91128 Palaiseau, France b Impact and Crashworthiness Laboratory, Massachusetts Institute of Technology, Cambridge, MA 02139, USA c ¨ The Angstrom Laboratory, Uppsala University, Box 534, SE-75121, Sweden a r t i c l e i n f o a b s t r a c t Article history: Accurate measurements of the forces and velocities at the boundaries of a dynamically loaded specimen Received 3 October 2008 may be obtained using split Hopkinson pressure bars (SHPB) or other experimental devices. However, the Received in revised form determination of a representative stress–strain curve based on these measurements can be challenging. 9 June 2009 Due to transient effects, the stress and strain fields are not uniform within the specimen. Several Accepted 23 September 2009 formulas have been proposed in the past to estimate the stress–strain curve from dynamic experiments. Available online 30 September 2009 Here, we make use of t