Large Shape Memory Alloy Composite Structures for Seismic Resistant Building Applications

KaZaK Composites and Professor DesRoches (Georgia Institute of Technology) propose to develop, build, and characterize large Nitinol Shape Memory Alloy (SMA) composite structures for applications in seismic-resistant framing connection elements. Recent earthquakes have highlighted the need for isolation and passive energy dissipation devices to enhance behavior of structures affected by seismic events. Current technologies have shortcomings that could potentially be overcome with passive composite SMA dampers and re-centering devices. SMAs have the ability to dissipate significant energy through repeated cycling without significant degradation or permanent deformation. There are no applications of SMA seismic dampers in the United States to date, however, largely due to the high cost of SMA materials and the fact SMAs have been available and fully characterized in fine wire form only. KCI will use its expertise in specialized pultrusion processing and other composite manufacturing methods to develop and demonstrate cost effective, high performance composite materials reinforced with standard continuous SMA wires, allowing devices of arbitrarily large size and shape to be cost effectively made with available SMA wire. The use of large diameter SMA composite dampers in seismic resistant design will be validated by characterizing mechanical properties, thermo-mechanical heat treatment, strain rate effects, and recovery properties.