Modified Taylor-tests with miniaturized samples

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

The role of the modified taylor impact test in dynamic material research

Dynamic material research with strain rates of more than 1000 1/s is experimentally very often done with a Split-Hopkinson Bar, Taylor impact tests or planar plate impact test investigations. At the Ernst-Mach-Institut (EMI), a variant of an inverted classical Taylor impact test is used by application of velocity interferometers of the VISAR type (“Modified Taylor Impact Test”, MTT). The conduction of the experiments is similar to that of planar plate impact tests. The data reduction and derivation of dynamic material data can also be restricted to an analysis of the VISAR signal. Due to these properties, nearly each highly dynamic material characterization in our institute done by planar plate investigations is usually accompanied by MTT experiments. The extended possibilities and usefulness of a combined usage of these two highly dynamic characterization methods are explained. Recently, further developed MTT experiments with very small specimen sizes are presented. For the first time, Taylor impact and planar impact specimen can be used for which the load directions even in case of thin plate test material are identical and not perpendicular to each other. Consequences for testing construction elements are discussed

Hugoniot data of Seeberger sandstone up to 7 GPa

Planar-plate impact tests were carried out for the measurement of Hugoniot data of dry Seeberger sandstone in the pressure range of up to 7 GPa. A special inverse testing method suitable for rock targets was applied together with a laser interferometer for the measurement of the free-surface velocity of the target plate required for the calculation of the particle velocity (up) and the shock wave velocity (US) in the sandstone specimen. In our measurement range (impact velocity between about 50m/s and about 1300 m/s), the US – up data show significant scattering. The travel times of the impact-induced shock waves indicate that pore crushing occurs. A strong dependance of the US – up data on the test batch selected for the impact experiments and, thus, on the mining location was observed. This dependance is greater than the scattering of the individual data sets

Instrumente der Marketingkommunikation: ein Überblick

Die Marketingkommunikation von Unternehmen spielt eine zentrale Rolle bei der Differenzierung von Produkten und Dienstleistungen im Wettbewerb. Hierbei stehen den Unternehmen insbesondere die Marketingkommunikationsinstrumente Mediawerbung, Public Relations, Verkaufsförderung, Sponsoring und Event Marketing zur Verfügung. Der Beitrag liefert einen Überblick über die Marketingkommunikation sowie dessen Instrumente. Abschließend wird die Frage der Kontrolle der Instrumente durch Unternehmen thematisiert