Rock Fragmentation Assessment of a Drill Bit by Hopkinson Bar Percussion Test

Advancements in the Split Hopkinson Bar Test

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...

Optimum Drill Bit Selection by Using Bit Images and Mathematical Investigation

This study is designed to consider the two important yet often neglected factors, which are factory recommendation and bit features, in optimum bit selection. Image processing techniques have been used to consider the bit features. A mathematical equation, which is derived from a neural network model, is used for drill bit selection to obtain the bit’s maximum penetration rate that corresponds ...

A non-equilibrium approach to processing Hopkinson Bar bending test data: Application to quasi-brittle materials

The aim of this paper was to describe a method of analysing the test data recorded during a Hopkinson Bar bending test. This three-point dynamic bending test was designed for testing the strength of materials under dynamic loads. It is carried out on a specimen consisting of a beam placed on two supports, which is subjected to an impact. The use of Hopkinson Bar as supports makes it possible to...

An Empirical Method of Dispersion Correction in the Compressive Hopkinson Bar Test

The dispersion of longitudinal stress waves as they propagate in pressure bars distorts the shape of the pulse, and so can be a limitation to the accuracy of high strain rate tests such as the compressive split Bopkinson pressure bar (SHPB). The method of dispersion correction described in this paper is based on a bar phase characteristic which is derived entirely from measured stress pulses ge...