Modified Taylor-tests with miniaturized samples

Fraunhofer Institute for High-Speed Dynamics, Ernst-Mach-Institut, EMI, Eckerstrasse 4, 79104 Freiburg, Germany

Abstract

A reversed Taylor-test with application of a velocity interferometer is in use at EMI, called modified Taylor-test (MTT). The experiment consists of impacting a fixed sample rod and observing the rear side of the sample by a velocity interferometer of the VISAR type. The setup enables to determine high-dynamic material data of the sample by evaluating the measured free surface velocity time curve. Normally, rods with a dimension of 6 mm diameter and 60 mm length have been investigated. Samples with this diameter are not producible from sheets: Sheet steels typically have a maximum diameter of 3 mm. Furthermore, it would be a general advantage to be able to work with small sample sizes when seldom or expensive materials have to be investigated. Therefore, efforts for reducing the sample size for MTTs have been made. In recent tests, Taylor rods of 1.5 mm diameter and a length of 15 mm have been used. VISAR data could be captured from these samples, which are comparable with data from larger-size MTTs. This finding offers new perspectives for high-dynamic testing of materials which only allow the production of small sample diameters.