Acta Mater. 61, 4996-5007, 2013

ELASTOPLASTIC BUCKLING AS SOURCE OF MISINTERPRETATION OF MICROPILLAR TESTS

B. Daum1, G. Dehm2,3,4, H. Clemens5, M. Rester3, F.D. Fischer6, F.G.Rammerstorfer1

1Institute of Lightweight Design and Structural Biomechanics,
TU Wien, Vienna, Austria
2Erich Schmid Institute for Materials Science, Leoben, Austria
3Department of Materials Physics, Montanuniversität Leoben, Austria
4Max-Planck-Institut für Eisenforschung, Düsseldorf, Germany
5Department of Physical Metallurgy and Testing, Montanuniversität Leoben, Austria
6Department of Mechanics, Montanuniversität Leoben, Austria


Abstract - Microscopic compression tests (micropillar tests) are typically used to obtain stiffness and strength properties of materials at small length scales. In this work it is shown that structural effects, in particular instabilities, have implications on the resulting load–displacement diagram. Care has to be taken when the measured load–displacement path of a micropillar is interpreted as a stress–strain path of the material. Several structural effects are discussed by means of computational analysis.
(hjb,130805)