Research and simulation on the thermal mechanical properties of functionally graded shape memory alloy composite beam considering tension-compression asymmetry

Considering the tension-compression asymmetry of Shape Memory Alloy (SMA), the tension and compression constitutive equations of the Functionally Graded Shape Memory Alloy (FG-SMA) beam are established based on the simplified constitutive relation of SMA. The influences of the power exponent, temperature, tension-compression asymmetry coefficient, and strain (along the length direction of the beam) on the martensite volume fraction and stress of the beam are analyzed, and the correctness of the theory is verified by comparing the results of theory with finite element analysis. The research shows that when the height of the beam is constant, the power exponent, temperature, tension-compression asymmetry coefficient are proportional (inversely proportional) to the stress (martensite volume fraction) of the cross-section, and the strain is proportional to both the stress and martensite volume fraction of the cross-section. When the other conditions are fixed, compared with compression, the martensite volume fraction (stress) under tension is larger (slightly less) at the same layer cross-section position.