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Research on Properties of a Shape Memory Alloy (SMA) Concrete
"Two-Way Beam" Applied in Underground Engineering
(1 The College of Civil Engineering of Chongqing University, Chongqing 400045; 2 Key Laboratory of Upland Urban Construction and New Technology, Ministry of Education, Chongqing University, Chongqing 400045; 3 School of Architecture Engineering, Chongqing Vocational Institute of Engineering, Chongqing 400037)
Abstract Based on the two-way shape memory effect of Shape Memory Alloy (SMA) , an SMA concrete "two-way beam" is put forward as a new kind of smart structure. Based on mechanical knowledge, the mechanical properties of a reinforced concrete beam and the SMA "two-way beam" were compared under three conditions (i.e., the temperature of the tensile part being greater than, lesser than and equal to the temperature of the compressive part). The recovery effect of the SMA beam was analyzed and calculated under a high excitation temperature. Additionally, problems to be solved before the application and promotion of the SMA concrete "two-way beam" are presented, along with suggested future research in the field. The results show that it is not an effective way to increase sectional dimensions to improve the stress state of a beam with temperature differences between the upper and lower surfaces; the stress mechanism analysis is in agreement with the computational analysis; the SMA has an actuating effect on "two-way beam" deformation during the phase transformation process and actively controls and adjusts the deflection value of the beam while decreasing the bending moment and axial force of the beam induced by temperature differences. This "two-way structure" can improve crack resistance and is suitable for underground engineering.
Abstract：
Based on the two-way shape memory effect of Shape Memory Alloy (SMA) , an SMA concrete "two-way beam" is put forward as a new kind of smart structure. Based on mechanical knowledge, the mechanical properties of a reinforced concrete beam and the SMA "two-way beam" were compared under three conditions (i.e., the temperature of the tensile part being greater than, lesser than and equal to the temperature of the compressive part). The recovery effect of the SMA beam was analyzed and calculated under a high excitation temperature. Additionally, problems to be solved before the application and promotion of the SMA concrete "two-way beam" are presented, along with suggested future research in the field. The results show that it is not an effective way to increase sectional dimensions to improve the stress state of a beam with temperature differences between the upper and lower surfaces; the stress mechanism analysis is in agreement with the computational analysis; the SMA has an actuating effect on "two-way beam" deformation during the phase transformation process and actively controls and adjusts the deflection value of the beam while decreasing the bending moment and axial force of the beam induced by temperature differences. This "two-way structure" can improve crack resistance and is suitable for underground engineering.
YIN ,
KE 1,
2 etc
.Research on Properties of a Shape Memory Alloy (SMA) Concrete
"Two-Way Beam" Applied in Underground Engineering
[J] MODERN TUNNELLING TECHNOLOGY, 2014,V51(2): 36-42
2014, Vol. 51 