Kolsky Compression Bar Experiments on Brittle Materials

Abstract

Many brittle materials deform in a manner of nearly linear elasticity until failure at small strains. As specimens in Kolsky-bar experiments, these materials are extremely sensitive to stress concentrations due to bar misalignment or non-parallel loading surfaces. To deform a linear elastic specimen at a constant strain rate, a loading pulse with constant stress rate is needed. This chapter describes the characteristics of brittle specimens, introduces the modifications to Kolsky bar necessary to achieve the desired and valid testing conditions on the specimen, and outlines the design of Kolsky compression bar experiments on brittle materials with step-by-step examples.