Testing with SHPB from quasi-static to dynamic strain rates

R. Othman; M.N. Bissac; P. Collet; G. Gary

doi:doi:10.1051/jp4:20020726

Issue		J. Phys. IV France Volume 110, September 2003


Page(s)		397 - 404
DOI		https://doi.org/10.1051/jp4:20020726

J. Phys. IV France 110 (2003) 397
DOI: 10.1051/jp4:20020726

Testing with SHPB from quasi-static to dynamic strain rates

R. Othman¹, M.N. Bissac², P. Collet² and G. Gary¹

¹ Laboratoire de Mécanique des Solides, UMR 7649, École Polytechnique, 91128 Palaiseau, France
² Laboratoire de Physique Théorique, UMR 7644, École Polytechnique, 91128 Palaiseau, France

Abstract
We have developed a new method for separating dispersive waves in elastic and viscoelastic rods from three-point strain and one-point velocity measurements. Stress, strain, displacement and velocity, which were supposed to be homogenous in a rod section, were therefore determined at any point ofthe bar. This method is based on the assumption of a one dimensional and single mode dispersive wave propagation. This method was used in the frequency domain and took into account wave dispersion. It was shown to be stable with respect to noise.

The measuring time is increased considerably. Subsequently, the maximum strain which can be measured in a material tested with a classical SHPB (Split Hopkinson Pressure Bar) set-up is also increased and is no more limited by the length of the bars.

The method was used to evaluate the rate sensitivity ofaluminum honeycomb over a wide range ofstrain-rates (from 10 ^-2 to 1000 s ^-1).