Copyright © 2011 Tech Science Press CMC, vol.23, no.3, pp.287-306, 2011
Fatigue Damage Accumulation in a Cu-based Shape
Memory Alloy: Preliminary Investigation
F. Casciati
1
, S. Casciati
2
, L. Faravelli
1
and A. Marzi
1
Abstract: The potential offered by the main features of shape memory alloys
(SMA) in Structural Engineering applications is object of attention since two decades.
The main issues concern the predictability of the material behavior and the fatigue
lifetime of macro structural elements (as different from wire segments). In this
paper, the fatigue characteristics, at given temperatures, of multigrain samples of
a specific Cu-based alloy are investigated. The results of laboratory tests on bar
specimens are discussed. The target is to model the manner in which the effects of
several loading-unloading cycles of different amplitude cumulate.
Keywords: Damage accumulation, Fatigue, Shape memory alloy, Training.
1 Introduction
The potential offered by the main features of shape memory alloys (SMA) in Struc-
tural Engineering applications is the object of scientific and technical attention
since more than two decades [Graesser-Cozzarelli, 1991; Dolce et al., 2000; Ip,
2000; Des Roches et al., 2004; Casciati-Faravelli, 2008; Casciati-van der Eijk,
2008; Casciati-Faravelli, 2009; Saiidi et al., 2009]. In these studies, macrostruc-
tural (multi grains) elements are considered and it is difficult to extend to them the
large amount of physical investigations and numerical modeling developed in liter-
ature for single crystal samples (see, for instance, [Meunier et al., 1996] as an early
reference).
Some fatigue studies for the classic Ni-Ti alloy were recently published [Nemat
Nasser-Guo, 2006; Roy et al., 2008; Zhang et al., 2008; Bertacchini et al., 2009].
Studies of the fatigue behavior of single-grain Copper-based SMA are also avail-
able in literature [Siredey-Eberhardt, 2000; Siredey et al. 2005].
In this paper, the fatigue characteristics, at given temperatures, of multigrain sam-
ples of a specific Cu-based alloy are investigated. The main issues concern the
1
University of Pavia, Pavia, Italy
2
University of Catania, Siracusa, Italy, saracasciati@msn.com