Application of Shape Memory Alloyed Material in End Plate Rigid Connection

As observed in Northridge (1994) and Kobe (1995) earthquakes, brittle failure of rigid connection caused premature collapse of steel moment frames and new rigid connections have been introduced in design guidelines of steel frames. Although the usage of new connections can lead to the appropriate function of steel moment frames, plastic hinges forms in beams which leaves the inelastic and permanent residual deformations after strong ground motions. Since this irremediable deformation increases repair cost, constructing rigid connections from reversible material such as Shape Memory Alloy (SMA) significantly reduce the residual strain and could be a solution to the problem. This paper focuses on the function of end plate connection using Iron-based SMA (possessing 5% of super elastic strain) by numerical study using ANSYS software. Following verification of cyclic behavior of an end plate connection tested by Sumner (designed on the basis of Thick Plate Theory), SMA is used as either connecting bolts for end plate-to-column connection or as plates located at plastic hinges. The result shows that using SMA plates is more efficient than SMA bolt in end plate connection which designed based on thick plate theory. Regarding appropriate weld ability and lower cost of iron-based SMA, hybrid connection equipped with mentioned plates is able to absorb lesser energy compared to steel connection. Moreover, it decrease repair cost whereas lower residual strain is seen.