An analytical study on SMA beam-column actuators for anti-buckling phenomenon

The present paper focuses on studying the anti-buckling behavior of prismatic martensitic shape memory alloy (SMA) beam-columns. It combines analytical and semi-analytical approaches to investigate the process of column straightening for anti-buckling. We try to comprehensively describe this phenomenon and develop a mathematical model to formulate each step of the anti-buckling problem. Due to the complex stress-strain behavior of SMA material, nine different stages of stress-height diagrams may potentially occur during this effect; thus, for facilitating the design process of SMA structures, corresponding forces and moments to each stage, are analytically derived. Our demonstration establishes that the primary cause of beam-column straightening is not the uniformity of stress, but rather the achievement of uniform strain across all fibers of the cross-section. This uniform strain distribution implies that the curvature of the beam-column diminishes to zero.