A three‐dimensional model describing stress‐temperature induced solid phase transformations: thermomechanical coupling and hybrid composite applications

Abstract

SUMMARYBetween composite materials, shape memory alloy (SMA) composites are having a more and more relevant role. Typically, SMA wires are embedded in a metallic or a polymeric matrix to obtain materials with native multi-functionality and adaptive properties. This work approaches the computational study of the mechanical response of a composite in which SMA wires, previously deformed, are activated by electrical current heating, and accordingly try to recover the original shape inducing a shape change or a prestress in the structure.In particular, since the SMA behaviour is strongly affected by the thermo-mechanical coupling, in the first part of this work we present a 3D phenomenological model able to take into account this aspect. The model time-discrete counterpart is used to develop a 3D solid finite element able to describe the thermo-electro-mechanical coupled problem due to shape memory alloy response and to Joule effect. Finally, in the second part of the paper, we employ the developed computational tool to simulate different feasible SMA composite applications.

Two-way thermomechanically coupled micromechanical analysis of shape memory alloy composites

“…The fully coupled thermomechanical equations of the monolithic SMA material were presented by Auricchio and Petrini [2002;2004b;2004a], who extended and improved the thermodynamical model of Souza et al [1998]. These equations are briefly presented below.…”

“…The above nonlinear equations have been treated by Auricchio and Petrini [2002;2004b;2004a] who employed for their solution a computational algorithm based on an implicit time procedure. This algorithm consists of integrating these equations over a time interval [t n , t n+1 ] using an implicit backward Euler scheme.…”

“…In order to investigate the behavior of the monolithic SMA material with two-way TMC, appropriate constitutive relations and the energy equation need to be established. To this end, Auricchio and Petrini [2004b] presented a free-energy function from which the required two-way TMC constitutive and energy equations were derived. The implementation of these equations requires the development of a computational algorithm based on an implicit time procedure, in conjunction with the radial return method [Simo and Hughes 1998].…”

“…In particular, the induced average temperatures that result from the two-way TMC are computed and presented under various circumstances. To this end, the constitutive two-way modeling of the SMA fibers of Auricchio and Petrini [2004b] is employed.…”

Development of Prestressed Concrete Using Fe–Mn–Si-Based Shape Memory Alloys Containing NbC

“…[2][3][4][5][6][7][8] For example, the SMA prestressed concrete can be produced through the following four steps: 1) pre-straining of SMAs, which induces the martensitic transformation, 2) installing the SMAs into freshly mixed concrete, 3) hardening the concrete, and 4) heating the SMAs to generate a shape recovery stress, which acts as a prestress. The above process is different from that of the conventional prestressed concrete, and therefore, a unique construction technique is possible.…”