A SUPERELASTIC SHAPE-MEMORY-ALLOY BEAM MODEL

The present paper proposes a simple shape-memory-alloy beam model, bas ed on the classical Euler-Bernoulli beam theory. Due to restrictive ki nematical assumptions, a one-dimensional constitutive equation is used . Thus, the material behavior is described through a simple 1-D phenom enological model, which allows for different material responses in ten sion and compression as well as for different elastic properties betwe en austenite and martensite. Two numerical procedures are developed fo r the determination of the cross-section response together with a time -step integration algorithm. Then, the implementation of the shape-mem ory-alloy beam model within a finite-element framework is addressed. S everal numerical examples are investigated to assess both the performa nce of the beam model and the procedure developed. The complex behavio r of a typical cross section is emphasized. The results obtained from the simulation of three-and four-point bending tests are compared both with experimental results and with numerical solutions obtained from a three-dimensional finite-element scheme.