Compressive behaviour of stainless steel micro-lattice structures


GÜMRÜK R. , Mines R. A. W.

INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES, cilt.68, ss.125-139, 2013 (SCI İndekslerine Giren Dergi) identifier identifier

  • Cilt numarası: 68
  • Basım Tarihi: 2013
  • Doi Numarası: 10.1016/j.ijmecsci.2013.01.006
  • Dergi Adı: INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
  • Sayfa Sayıları: ss.125-139

Özet

This paper focuses on investigating the mechanical static compression behaviour of 316L stainless steel micro-lattice materials manufactured using selective laser melting method. In theoretical and numerical approaches, the material overlapping effects in the vicinity of strut connection points is taken into consideration to give reasonable predictions corresponding to the initial stiffness and strength values. In theoretical studies, Timoshenko beam model is used to consider the shear effect in calculation of initial stiffness. In addition, to include work hardening of micro struts in calculation of collapse strength a model is developed. Experiments have shown that mechanical response of micro lattice structures is governed by their aspect ratio. The theoretical predictions are quite close to experiments. Finite element models simulate the initial stiffness and strength values related to experimental tests, although there are some small differences in loading history, resulting from the complex strut joint geometry and variable diameter. Also, within the scope of this paper, the stress-strain curves of an individual defected micro strut manufactured using selective laser melting method are measured using an efficient method and the elasticity modulus for the defected micro strut is found as 97 GPa, which is 60% lower than bulk material. As a result, the findings show that in the micro scaled structures, the geometry of connection points and material overlapping should be taken into account to find the proper results in terms of mechanical responses in theoretical studies as well as finite element models. (c) 2013 Elsevier Ltd. All rights reserved.