Seismic Performance Improvement of Steel Moment Resisting Frame Using Shape Memory Alloy

Bajoria KM and Jadhav RV

Abstract

Shape Memory Alloys have a wide range of applications due to their special properties. The properties like shape memory effect, super elasticity (SE) and high damping are useful to enhance structural behavior and seismic resistance. In this paper, super elasticity effect of two different alloys NiTi and Fe based SMA is used to enhance the structural properties of a steel Moment Resisting Frame and comparison of response of frame with connection of two different alloys is studied. The finite element analysis of moment resisting frames is done using Ansys-15. The geometry and loading conditions of frames are taken from previous research. For the comparison of structural behavior of the steel frame with Shape Memory Alloy at beam column connection are checked for lateral loading. Also, the response of the frame is checked for time history analysis using past earthquake data. Comparison of the time history analysis response of bare frame (Steel only connections) and frame with SMA at connection suggested excellent performance of frame equipped with SMA. The main aim of the study is reducing residual displacement of steel frames after earthquake loading. To check the performance of the frame for loading unloading cycle, incremental lateral loading is applied to the frame up to maximum load and then it is unloaded completely. The SMA equipped frame shows almost 85% recovery of the residual displacement. The reduction in residual displacement of the SMA equipped frame is also seen in case of time history analysis. Though Ni-Ti SMAs show a little more recovery in residual displacement, cost comparison shows using Fe based SMA in Civil Engineering industry will be beneficial for the maximum utilization of material with lesser cost.

Relevant Publications in Steel Structures & Construction