In previous research, post-tensioned glass beams with pre-stressed tendons made of stainless steel or fiber-reinforced plastics (FRP) have shown an improved structural performance compared to glass beams without or with non-pre-stressed reinforcing tendons. However, post-tensioned glass beams have only been used in very few projects until now, among other reasons, due to the rather complex setups required for pre-stressing stainless steel or FRP tendons. Iron-based shape memory alloys (Fe-SMAs), which exhibit high strength and ductility, proved as promising alternative materials for post-tensioning in previous projects dealing with strengthening concrete and steel structures. Target post-tensioning levels can be obtained by anchoring pre-strained Fe-SMA tendons to the parent structure, heating them to corresponding temperatures, and letting them cool back to ambient temperature. A previous feasibility study conducted at room temperature has shown that both the initial and the post-fracture load-bearing capacity of laminated glass beams can be increased by post-tensioning the beams with Fe-SMA strips adhesively bonded to their edges. Considering possible applications of laminated glass beams to support transparent roofs or facades and the temperature range to which the beams can be exposed, this contribution addresses the bond behavior of glass to Fe-SMA lap-shear joints with a selected epoxy adhesive at different temperature levels. The load-carrying capacity, failure mode and approximate effective bond length will be evaluated. The obtained experimental results will emphasize the performance and limitations of the selected adhesive at different temperatures and significantly contribute to the future application of adhesively bonded Fe-SMA tendons for post-tensioning glass elements.
Structural Performance of Glass to Iron-based Shape Memory Alloy Adhesive Shear Joints Considering the Effect of Temperature
Company: ETH Zurich, Zurich, Switzerland
About the speaker:
Zhikang Deng is a PhD student in ETH Zurich, Switzerland. He is currently working on reinforcing glass elements with adhesively bonded Iron-based shape memory alloy. Before his carrier in ETH Zurich, He was working on fatigue and fracture analysis of FRP/CFRP in TU delft and Wuhan University of Technology, China.