About the use of micro-indentation to determine the constitutive material’s mechanical behaviour of cellular structures
Av. de la Division Leclerc, BP 72, 92322
a e-mail: Vincent.Marcadon@onera.fr
Architectured cellular materials seem to be very promising materials since they can combine interesting speciﬁc mechanical, acoustical and thermal properties. Nevertheless the process routes used to elaborate such materials, especially the thermal treatments and the added compounds, may alter their constitutive materials for which the mechanical behaviour becomes unknown. In order to determine locally the mechanical behaviour of the constitutive materials of cellular structures we propose the use of microindentation. The model structures considered here are brazed tube stackings. Macroscopic tensile tests and micro-indentation measurements have been performed on isolated tubes having been submitted to different thermal treatment durations. The mechanical properties estimated thanks to both methods show a good agreement. These results also put in evidence the strong inﬂuence of the thermal treatment on the behaviour of the constitutive material of the tubes. Micro-indentation measurements performed in the braze joints gave access to their mechanical properties which are strongly heterogeneous. A comparison between the experimental mechanical response of the tube stackings under compression and the one predicted by the ﬁnite-element method is proposed too.
© Owned by the authors, published by EDP Sciences, 2010