Issue 29

V. Sepe et alii, Frattura ed Integrità Strutturale, 29 (2014) 85-96; DOI: 10.3221/IGF-ESIS.29.09 93 to a heterogeneous material able to dissipate more than shape memory alloys characterized by low porosity or dense material. Figure 4 : Maximum average normal stress for the considered porosities provided by the two loading histories. Figure 5 : Dissipated energy per solid volume for the considered porosities provided by the two loading histories. C ONCLUSIONS he mechanical behavior of porous SMA has been investigated in the present work. The simplifying hypothesis of considering a periodic distribution of voids all characterized by the same shape and dimensions has been assumed so that a typical repetitive unit cell, representative of the heterogeneous material and able to account for the properties of the composite medium, has been analyzed. The model proposed by [15] and [16] for dense SMA has been adopted to reproduce the constitutive behavior of porous shape memory alloys. 0 0.1 0.2 0.3 0.4 0.5 0.6 0 500 1000 1500 2000 2500 3000 Voids Fraction Loading history 1 Loading history 2   max 11 MPa  0 0.1 0.2 0.3 0.4 0.5 0.6 1 2 3 4 5 6 7 Voids Fraction Dissipated Energy / Solid Volume [MJ/m 3 ] Loading history 1 Loading history 2 T