Dynamic necking can avoid notches

Following an earlier post on dynamic necking of tensile bars, we show in the attached paper (to appear in JMPS) that the presence of deep notches in the specimen does not necessarily dictate the location of the neck. Various material parameters are identified and modeled numerically, to assess their respective influence. Strain-rate sensitivity is identified as an important factor. Stated simply, given the fact that local strain rates in a notch are significantly higher than in the rest of the bar, the notch will harden to an extent that it transfers the load elsewhere in the specimen. 

Besides being an interesting counter-intuitive observation, this work has also practical implications for the design of dynamically tensioned bars that are expected to fail at the "right" place and at the "right" time.

Comments are welcome, as usual.