A temperature-dependent beam for shape-memory alloys: constitutive modelling, finite-element implementation and numerical simulations

This paper presents a thermomechanical one-dimensional constitutive model b ased on the use of strain and temperature as control variables and able to reproduce the basic responses of shape-memory materials, such as superelast icity, the shape-memory behavior, different response in tension and compres sion, single-variant martensite reorientation process. The model time-integ ration is performed and a robust algorithm for the solution of the time-dis crete model is addressed together with the algorithmically consistent tange nt. The model is also implemented in a small-deformation beam finite-elemen t, which is used to simulate the following applications exploiting the supe relastic and/or the shape-memory effect: tensile, pure bending and three-po int bending tests, orthodontic wires, two-way (linear and angular) mechanis ms. The numerical investigations show that the proposed procedure is an eff ective computational tool for the simulation of a broad range of applicatio ns based on shape-memory materials. (C) 1998 Elsevier Science S.A. All righ ts reserved.