TY - JOUR

T1 - Influence of activation temperature and prestress on behavior of Fe-SMA bonded joints

AU - Li, Lingzhen

AU - Chatzi, Eleni

AU - Czaderski, Christoph

AU - Ghafoori, Elyas

N1 - Funding Information: The authors acknowledge the China Scholarship Council (CSC) for co-financing the PhD project of the first author. re-fer AG and Sika AG are appreciated to provide Fe-SMA and adhesive materials, respectively. Special thanks go to Mr. André Kupferschmid from the Transport at Nanoscale Interfaces Laboratory at Empa and Mr. Giovanni Saragoni and Mr. Robert Widmann in the Bauhalle team at Empa for their technical support.

PY - 2023/12/15

Y1 - 2023/12/15

N2 - The prestressed strengthening of structures via use of bonded iron-based shape memory alloys (Fe-SMAs) has proven promising, albeit with concerns regarding the temperature dependency of the adhesive properties. In this study, the effect of activation temperature and generated prestress are investigated experimentally. Six Fe-SMA-to-steel adhesively bonded joints, comprising different Fe-SMA strips (non-prestrained and prestrained) and activation strategies (full activation and partial activation), were prepared, activated via electrical resistance heating, and tested under quasi-static loading. It is found that the bond–slip behavior of a joint with activation can be modeled by that of an equivalent non-activated joint. The generated prestress influences the full-range behavior by raising the base tensile stress level of the Fe-SMA strip, with negligible effects on further aspects of the full-range behavior. With the increasing activation temperature, the fracture energy is initially increased and eventually reduced, while the bond capacity and effective bond length are retained almost constant.

AB - The prestressed strengthening of structures via use of bonded iron-based shape memory alloys (Fe-SMAs) has proven promising, albeit with concerns regarding the temperature dependency of the adhesive properties. In this study, the effect of activation temperature and generated prestress are investigated experimentally. Six Fe-SMA-to-steel adhesively bonded joints, comprising different Fe-SMA strips (non-prestrained and prestrained) and activation strategies (full activation and partial activation), were prepared, activated via electrical resistance heating, and tested under quasi-static loading. It is found that the bond–slip behavior of a joint with activation can be modeled by that of an equivalent non-activated joint. The generated prestress influences the full-range behavior by raising the base tensile stress level of the Fe-SMA strip, with negligible effects on further aspects of the full-range behavior. With the increasing activation temperature, the fracture energy is initially increased and eventually reduced, while the bond capacity and effective bond length are retained almost constant.

KW - Activation of prestress

KW - Debonding

KW - Full-range behavior

KW - Local heating damage

KW - Memory steel (Fe-SMA)

UR - http://www.scopus.com/inward/record.url?scp=85176100416&partnerID=8YFLogxK

U2 - 10.1016/j.conbuildmat.2023.134070

DO - 10.1016/j.conbuildmat.2023.134070

M3 - Article

AN - SCOPUS:85176100416

VL - 409

JO - Construction and Building Materials

JF - Construction and Building Materials

SN - 0950-0618

M1 - 134070

ER -