Non-contact and real-time measurement of Kolsky bar with temporal speckle interferometry

In this paper, a new non-contact and real-time measurement system for Kolsky bars is presented. This system uses two sets of temporal speckle interferometry in-plane displacement measurement devices to replace two strain gauges of conventional Kolsky bars. The in-plane displacement measurement of the Kolsky bar is mainly intended to provide a new test method for the dynamic mechanical properties of small-size material samples with diameters below 2 mm. This method is non-contact, does not require any intermediate medium, and can make the Kolsky bar applicable to characterizing the dynamic mechanical properties of materials under higher strain rates and smaller size conditions. The measuring devices and principles are described. In addition, a preliminary experiment is carried out to demonstrate the performance of this new device.