Study Of structural Behaviour And Residual Drift Of Concrete frames Reinforced With Shape Memory Alloy Rebar

Document Type : Original Article

Authors

1 Associate Professor, Department of Civil Engineering, K.N. Toosi University of Technology,Tehran, Iran

2 M.Sc. of Earthquake Engineering

3 K.N.toosi department of civil engineering

4 MSc

Abstract

Buildings in high seismic regions are prone to severe damage and collapse during earthquakes due to large lateral deformations. The use of superelastic shape memory alloys (SMAs) as reinforcements in concrete structures is gradually gaining interest among researchers. the effect of SMAs as reinforcement in concrete structures is analytically investigated for 3, 6 and 8-story reinforced concrete (RC) buildings. Each building has five bays in both directions with the same bay length of 5m. For each concrete building, three different reinforcement details are considered: (1) steel reinforcement (Steel), (2) SMA bar used in the plastic hinge region of the beams and steel bar in other regions (Steel-SMA), and (3), beams fully reinforced with SMA bar (SMA) and steel bar in other regions. For each case, columns are reinforced with steel bar. Results obtained from the analyses indicate that the value of Sa in Steel-SMA frames are higher than SMA frames, and its recovery capacity is almost similar with SMA frames. the SMAs materials are expensive, and the use of Steel-SMA frames can be reasonably effective in seismic zones. The comparison between frames with various reinforcements details shows that Sa of 3-story frames with various reinforcements are almost identical. but, in 6- and 8-story frames, Sa of Steel frames are higher than others. frames with SMA bars in the all length or plastic hinge region of the beam have reached a same level of seismic demand under lower spectral acceleration which can be resulted from the decreased stiffness caused by SMA bars. results indicate that structural behaviour factor in 3 and 6 story buildings with different types of reinforcement is not much change, but this change is perceptible in the 8-story frame. In the case of residual drift in all cases, the use of shape memory alloys will reduce this drifts.

Keywords

Main Subjects


[1] Alam, M.S., Youssef, M.A. and Nehdi, M. (2008), “Analytical prediction of the seismic behavior of superelastic shape memory alloy reinforced concrete elements”, Engineering Structures, 30, pp. 3399–3411.
[2] Alam, M.S., Youssef, M.A. and Nehdi, M. (2007), “Seismic behavior of concrete beam-column joints reinforced with super-elastic shape memory alloys”, 9th Canadian Conference on Earthquake Engineering June 2007, ON, Canada, Paper No.1125, p. 10.
[3] Srinivasan, A.V. and McFarland, M.D. (2001), “Smart structures – analysis and design”, Cambridge university press.
[4] Anson, T., (1999), “Shape Memory Alloys - Medical Applications”, Materials World, Vol. 7, No. 12, December 1999, pp. 745–747.
[5] Dolce, M. and Cardone, D. (2001), “Mechanical behaviour of shape memory alloys for seismic applications1. Martensite and austenite NiTi bars subjected to torsion”, International Journal of Mechanical Sciences, 43, pp. 2631–2656
[6] Dolce, M. and Cardone, D. (2001), “Mechanical behaviour of shape memory alloys for seismic applications 2. Austenite NiTi wires subjected to tension”, International Journal of Mechanical Sciences, 43, pp. 2657–2677.
[7] Ocel, J., DesRoches, R., T.Leon, R., Hess, W.G., Krumme, R., Hayes, J.R. and Sweeney, S.(2004),“Steel beam-column connections using shape memory alloys”, Journal of Structural Engineering, Vol. 130, pp. 732-740.
[8] G. Song, N. Maa, H.-N. Li., (2006), “Applications of shape memory alloys in civil structures” Engineering Structures, 28, pp. 1266–1274
[9] Motahari, S.A., Ghassemieh, M. and Abolmaali, S.A., (2007), “Implementation of shape memory alloy dampers for passive control of structures subjected to seismic excitations” Journal of Constructional Steel Research, Volume 63, No. 12, pp. 1570–1579.
[10] Abdulridha, A., Palermo, D., and Foo, S. (2010), “Seismic behavior of SMA reinforced concrete beams” 9th US National and 10th Canadian Conference on Earthquake Engineering: Reaching Beyond Borders, Toronto, Canada, and July, 2010.
[11] Khaloo, A. R., Eshghi, I. and Piran Aghl, P. (2010), “Study of Behavior of Reinforced Concrete Beams with Smart Bars Using Finite Element Modeling”, International Journal of Civil Engineering. Vol. 8, No. 3, September 2010.
[12] Omar, M. (2011), “Analytical prediction of seismic response of steel frames with superelastic shape memory alloy”. World Academy of Science, Engineering and Technology, International Journal of Environmental, Chemical, Ecological, Geological and Geophysical Engineering Vol. 5, No. 11.
[13] Alvandi, S. and Ghassemieh, M. (2014), “Application of shape memory alloys in seismic isolation”. Civil Engineering Infrastructures Journal, 47(2), pp. 153 – 171.
[14] Alam, M.S., Moni, M. and Tesfamariam, S. (2012), “Seismic over-strength and ductility of concrete buildings reinforced with superelastic shape memory alloy bar”, Engineering Structures, 34 pp. 8–20.
[15] Alam, M.S., Nehdi, M and Maged, A.Y. (2009), “Seismic performance of concrete frame structures reinforced with superelastic shape memory alloys”, Smart Structures and Systems, Vol. 5, No. 5 pp. 565-585.
[16] FEMA. Recommended seismic design criteria for new steel moment-frame buildings. Report No. FEMA-350, SAC Joint Venture, Federal Emergency Management Agency, Washington DC 2000.
[17] NBCC., 2005, National Building Code of Canada,Canadian Commission on Building and Fire Codes. Ottawa: National Research Council of Canada.
[18] CSA, 2004, A23.3-04. Design of Concrete Structures. 5th ed. Rexdale, ON,Canada: Canadian Standards Association.
[19] Alam, M.S., Moni, M. and Tesfamariam, S. (2012), “Seismic over-strength and ductility of concrete buildings reinforced with superelastic shape memory alloy bar”, Engineering Structures, 34 (2012) 8–20.
[20] H. Mirzaeefard؛ S.M. Mirtaheri؛ H. Rahmani Samani(2016) “Response modification factor of steel structures equipped with cylindrical frictional dampers." Amirkabir Journal of Civil & Environmental Engineering (In Persian) 31-40:(3)49