Kolsky Compression Bar Experiments at Intermediate Strain Rates

Abstract

Most Kolsky bars characterize dynamic material properties at strain rates between 5×0² and 1×10⁴ s^-1. On the other hand, quasi-static material testing machines operate under closed-loop control at strain rates below 1 s^-1. However, many applications require stress-strain data around the intermediate strain-rate range of 5×10¹ - 5×10² s^-1, where data is scarce for any material. This chapter describes designs of Kolsky bars to conduct dynamic experiments at strain rates below 10² s^-1, which is the upper limit of modified quasi-static methods. The overlap in strain rates achieved by the modified Kolsky bar and quasi-static techniques bridges the gap in the intermediate strain-rate range, which also facilitates the system-error examination between the quasi-static and dynamic testing methods.