Strain measuring accuracy with splitting-beam laser extensometer technique at split Hopkinson compression bar experiment

Advancements in the Split Hopkinson Bar Test

Using split Hopkinson pressure bars to perform large strain compression tests on polyurea at low, intermediate and high strain rates

The strain rate sensitivity of polyurea is characterized using a modified split Hopkinson pressure bar (SHPB) system. The device is composed of a hydraulic piston along with nylon input and output bars. In combination with an advanced wave deconvolution method, the modified SHPB system provides an unlimited measurement time and thus can be used to perform experiments at low, intermediate and hi...

Improved specimen recovery in tensile split Hopkinson bar.

This paper presents an improved specimen recovery method for the tensile split Hopkinson bar (TSHB) technique. The method is based on the trapping of residual stress waves with the use of momentum trap bars. As is well known, successful momentum trapping in TSHB is highly sensitive to experimental uncertainties, especially on the incident bar side of the set-up. However, as is demonstrated in t...

Using the split Hopkinson pressure bar to validate material models.

This paper gives a discussion of the use of the split-Hopkinson bar with particular reference to the requirements of materials modelling at QinetiQ. This is to deploy validated material models for numerical simulations that are physically based and have as little characterization overhead as possible. In order to have confidence that the models have a wide range of applicability, this means, at...

Stress Equilibrium in the Split Hopkinson Pressure Bar Test

The compressive split Hopkinson pressure bar (SHPB) technique allows the stresses on each end of the specimen to be measured individually. Results are presented showing a large difference between these end pressures, depending on specimen length and loading rate. The mechanisms responsible are shown to be a combination of inertial forces and non-uniform deformation due to wave propagation. Impl...