Dynamic testing of materials: Selected topics

Dynamic testing of materials is a vast subject involving a large variety of techniques according to the investigated properties. Consequently, one cannot cover it extensively and the present chapter will address three selected topics that were discussed during the lecture series given at CISM. For those subjects, the main experimental tool is the Split Hopkinson Pressure Bar (SHPB, Kolsky apparatus), used in its two or one bar version. The SHPB is extensively covered in another chapter so that we will assume that the reader is reasonably familiar with this technique, and will focus here on selected applications, noting that the SHPB is, before anything else, an experimental setup that allows for determination of the boundary conditions (load, displacements) applied to a structure (a specimen being in that case a special case of structure). The following topics will be addressed:

Dynamic fracture of materials:

Here we will present the one-point impact technique and its applications to both fracture mechanics testing, and also to dynamic tensile testing of quasi-brittle materials.

Pressure sensitivity of materials:

We will describe the basic technique and its application to metallic and polymeric materials, with selected results.

Thermomechanical couplings:

We will address here the effect itself, followed by various experimental techniques to measure transient temperature changes in impacted solids, followed by selected results.

As alluded before, such a chapter cannot be extensive, and is based mostly on the author’s experience. However, we will outline throughout the text relevant references that will allow the reader to expand his knowledge on the field.