Volume 2, 2009DYMAT 2009 - 9th International Conference on the Mechanical and Physical Behaviour of Materials under Dynamic Loading
|1231 - 1237
|15 September 2009
Modeling Bauschingher's effect in planar impactY. Partom
RAFAEL, PO Box 2250, Haifa 31021, Israel
Published online: 15 September 2009
Bauschinger's effect (BE) was first noticed as a decrease in yield stress upon unloading from a plastic state in standard tension-compression tests. It was later established that BE is quite general in terms of materials and modes of loading. Generalizing, BE may be regarded as anisotropic plasticity (in stress space) caused by the plastic flow itself. BE was extensively researched as part of an ongoing effort to understand and model cyclic plasticity. Cyclic plasticity models are based on the concept of kinematic hardening, are usually very complex, and contain many material parameters to be calibrated from tests. Here we're concerned with modeling BE in dynamic situations, specifically planar impact tests. In these tests BE is manifested by the so called Quasi-Elastic (QE) response upon unloading from the shock plateau level. Our approach is based on ideas put forward since the 1930s. First we show that our model, which we call Effective Grains Model (EGM), can reproduce the main modes of response in the plastic range, including BE. Then we apply it to planar impact tests and show that it can reproduce the QE response.
© EDP Sciences 2009