Effect of Plastic Hinge Length in Column Reinforced with Iron Based SMA

Failure of the columns occurs due to earthquakes. Hence, it demands performance improvement and post- earthquake functionality of the columns. The use of innovative material like Shape Memory Alloy (SMA) provides significant promises in performance improvement of columns. SMAs are unique materials that have the ability to undergo large inelastic deformations, make the structure reusable after strong earthquake. It is assumed that maximum seismic damage occurs at plastic hinge regions which necessitate the prediction of plastic hinge length for columns. The use of SMA as reinforcement in plastic hinge regions undergoes large elastic deformations with less permanent deformation. In the present study, two iron based SMAs namely, FeNCATB and FeMnAlNi are provided in varying lengths as longitudinal reinforcements for different column models. The numerical analyses of the columns are done using finite element software SeismoStruct. The effect of varying critical regions on load carrying capacity, maximum displacement, residual displacement and ductility of the columns are evaluated under reverse cyclic loading with constant axial load. Plastic hinge length of each model is obtained from their respective strain profiles.