Use of Shape Memory Alloy for different components in steel structures

Abstract

The structure is said to be smart structure if the behaviour of the structure will change depending on the conditions. To make the structure smart or to make them capable for various conditions mainly there are major two approaches are there. First one is to use some better structural system which is mostly used by all the designers. Lot of work has been done already by this approach. Here you provide moment resisting frames or diagrid structure or tubular structure or different type of bracing or shear walls. The other approach is to introduce some different type of element in the structure. Depending on the material properties and behaviour of the material the amount of use and at which position it is to be used needs to be decided. Not much amount of work has been done by this approach. Researcher has developed new materials called as smart alloys or shape memory alloys. It has got super elastic properties so that on large deformation also the come back to its original shape. So the residual deformations in the structure formed after the earthquake can be reduced and the capacity of the structure will increase. The nitinol is one of the shape memory alloy is used in the steel structure at different locations keeping the train restricted up to 8% only and the effect of that element on other steel element is observed for static conditions. The best possible location is checked for the dynamic condition and it is found that if the steel connections are replaced by SMA connections then the residual deformation and stress in the structure can be reduce to very large extent.