Numerical study of the seismic performance of shape memory alloys yielding metal dampers

With the development of new engineering materials, such as shape memory alloys, their use in civil engineering applications has increased greatly. Thus, in the present study, the mechanical behavior of yielding metal dampers made from shape memory alloys in steel frames is investigated numerically. For the purposes of evaluating the seismic performance of the proposed new system, a nonlinear static analysis has been conducted using the ABAQUS software. Using Brinson's behavioral model with considering the phase transformations, as well as the Drucker-Prager failure criteria, we were able to simulate the superelastic behavior of shaped memory alloy materials, both of which were implemented in ABAQUS with the UMAT subroutine. We have continued this investigation by studying the effect of geometric variables on the performance of the system as well as the stiffness, ductility, and energy absorption capacity of the different specimens. The damper that we propose is capable of providing high energy absorption and can be easily replaced by other flowing metal dampers such as TADAS and ADAS. The proposed system shows a significant improvement in terms of ductility and energy absorption as compared to the braced frame with a corresponding steel damper, which can be used in various engineering applications.