Details
| Original language | English |
|---|---|
| Article number | 117042 |
| Journal | Construction and Building Materials |
| Volume | 229 |
| Publication status | Published - 30 Dec 2019 |
| Externally published | Yes |
Abstract
This work discusses the development process of a direct fastening technique for strengthening steel members using iron-based shape memory alloy (Fe-SMA) strips. First, several lap-shear tests were performed to examine the efficiency of five nail-anchor systems in terms of load-carrying capacity, slippage, and convenience of installation. To this end, 3D optical digital image correlation (DIC) measurements (using an ARAMIS system) and numerical simulation were conducted. Different failure modes including tensile rupture of the strips, shear rupture of the nails, and/or sliding of the strips were observed and discussed. The optimum nail-anchor system was then determined. This system has a very short anchorage length of approximately 50 mm and only 12 nails (i.e., 3 × 4). Second, to demonstrate the efficiency of the proposed system, a steel I-beam was strengthened with the selected nail-anchor system and activated using an infrared heating (IRH) technique. The SMA-strengthened beam was subjected to static and then high-cycle fatigue loadings with a loading ratio of R=0.2 for 2.5 million cycles without any failure or damage, indicating reliable performance of the system. Owing to the larger coefficient of thermal expansion of the Fe-SMA material compared to that of steel, it was observed that a decrease and increase in the environmental temperature resulted in an increase and decrease of the pre-stress level in the Fe-SMA strip, respectively (i.e., an inverse correlation).
Keywords
- Direct fastening, Iron-based shape memory alloy (Fe-SMA), Nailing anchorage, Pre-stressing, Steel beam, Strengthening
ASJC Scopus subject areas
- Engineering(all)
- Civil and Structural Engineering
- Engineering(all)
- Building and Construction
- Materials Science(all)
- General Materials Science
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In: Construction and Building Materials, Vol. 229, 117042, 30.12.2019.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Development of nail-anchor strengthening system with iron-based shape memory alloy (Fe-SMA) strips
AU - Fritsch, Emil
AU - Izadi, Mohammadreza
AU - Ghafoori, Elyas
N1 - Publisher Copyright: © 2019 Elsevier Ltd
PY - 2019/12/30
Y1 - 2019/12/30
N2 - This work discusses the development process of a direct fastening technique for strengthening steel members using iron-based shape memory alloy (Fe-SMA) strips. First, several lap-shear tests were performed to examine the efficiency of five nail-anchor systems in terms of load-carrying capacity, slippage, and convenience of installation. To this end, 3D optical digital image correlation (DIC) measurements (using an ARAMIS system) and numerical simulation were conducted. Different failure modes including tensile rupture of the strips, shear rupture of the nails, and/or sliding of the strips were observed and discussed. The optimum nail-anchor system was then determined. This system has a very short anchorage length of approximately 50 mm and only 12 nails (i.e., 3 × 4). Second, to demonstrate the efficiency of the proposed system, a steel I-beam was strengthened with the selected nail-anchor system and activated using an infrared heating (IRH) technique. The SMA-strengthened beam was subjected to static and then high-cycle fatigue loadings with a loading ratio of R=0.2 for 2.5 million cycles without any failure or damage, indicating reliable performance of the system. Owing to the larger coefficient of thermal expansion of the Fe-SMA material compared to that of steel, it was observed that a decrease and increase in the environmental temperature resulted in an increase and decrease of the pre-stress level in the Fe-SMA strip, respectively (i.e., an inverse correlation).
AB - This work discusses the development process of a direct fastening technique for strengthening steel members using iron-based shape memory alloy (Fe-SMA) strips. First, several lap-shear tests were performed to examine the efficiency of five nail-anchor systems in terms of load-carrying capacity, slippage, and convenience of installation. To this end, 3D optical digital image correlation (DIC) measurements (using an ARAMIS system) and numerical simulation were conducted. Different failure modes including tensile rupture of the strips, shear rupture of the nails, and/or sliding of the strips were observed and discussed. The optimum nail-anchor system was then determined. This system has a very short anchorage length of approximately 50 mm and only 12 nails (i.e., 3 × 4). Second, to demonstrate the efficiency of the proposed system, a steel I-beam was strengthened with the selected nail-anchor system and activated using an infrared heating (IRH) technique. The SMA-strengthened beam was subjected to static and then high-cycle fatigue loadings with a loading ratio of R=0.2 for 2.5 million cycles without any failure or damage, indicating reliable performance of the system. Owing to the larger coefficient of thermal expansion of the Fe-SMA material compared to that of steel, it was observed that a decrease and increase in the environmental temperature resulted in an increase and decrease of the pre-stress level in the Fe-SMA strip, respectively (i.e., an inverse correlation).
KW - Direct fastening
KW - Iron-based shape memory alloy (Fe-SMA)
KW - Nailing anchorage
KW - Pre-stressing
KW - Steel beam
KW - Strengthening
UR - http://www.scopus.com/inward/record.url?scp=85072703370&partnerID=8YFLogxK
U2 - 10.1016/j.conbuildmat.2019.117042
DO - 10.1016/j.conbuildmat.2019.117042
M3 - Article
AN - SCOPUS:85072703370
VL - 229
JO - Construction and Building Materials
JF - Construction and Building Materials
SN - 0950-0618
M1 - 117042
ER -