Phase transformation mechanical behavior of functionally graded shape memory alloy beams

Abstract

Based on the bending deformation theory of the beam, combined with stress-strain relationship and the critical stress-temperature relationship of the shape memory alloy materials, the nonlinear governing equation of the functionally graded shape memory alloy statically indeterminate beam was obtained, and its mechanical behavior under the thermal-mechanical load was investigated. The phase transformation process of the beam was analyzed by a step-by-step method, and the influence of mechanical load, the tension-compression asymmetry coefficient, power exponent and temperature on the displacement of the neutral axis, curvature and phase boundary were obtained. The results draw that as the increase of the load, the displacement of neutral axis and the curvature become larger and the phase boundary is farther away from the edge of the section; the more the temperature and the power exponent are, the smaller the displacement of neutral axis and curvature will be, and the phase boundary become closer to the edge of the section; the tension-compression asymmetry coefficient has a greater influence on the phase boundary of the compressive side, but it has a weak influence on the phase boundary of the tensile side.

Keywords

• functionally graded shape memory alloy
• statically indeterminate
• phase transformation
• the tension-compression asymmetry coefficient