Measurements of Strain Propagation in Hopkinson Bar Specimens

摘要

The research presented continues the development of speckle metrology as a tool for making novel measurements using the split Hopkinson pressure bar (SHPB). Here, speckle is used to observe and quantify strain propagation in long specimens, by measuring the deformation field in the specimen as a function of time as an elastic wave passed through it. By combining these measurements with calculations of the stress in the specimen it is hoped to measure a high strain rate equivalent to the elastic modulus: the relationship between stress and strain in a propagating wave. The experiment outlined is a first step in this development.