A platform for research: civil engineering, architecture and urbanism
A platform for research: civil engineering, architecture and urbanism
Deformation energy of NiTi shape memory wires
Research highlights ► Deformation energy of B2 and R phase NiTi wires was studied by the MTT method. ► Superelastic energy for B2 wire was higher than the shape memory energy for R wire. ► The secondary elastic energy of was marginally higher for the B2-phase wires. ► Strain rate had little effect on the deformation energies of the B2-phase wires. ► The energy components of the R-phase wires were improved by increasing strain rate.
Abstract Deformation energy of NiTi wires with B2 and R phases was studied by the multiple tensile testing (MTT) method. In traditional materials, the total energy required to tear specimens is assumed to be the sum of elastic, uniform plastic, and post-uniform or tearing energy components. For the shape memory alloys, however, this classification is not valid due to their unusual superelastic/shape memory characteristics. Using a modified MTT method, different energy components were calculated by plotting different combination of deformation energies divided by the specimen cross-sectional area against the gage length of the specimens. The slope of the obtained straight line demonstrates the summation of the elastic, superelastic/shape memory, second elastic, and plastic energy per unit volume and its intercept gives the value of tearing energy. It was found that the uniform plastic energy per unit volume for the R-phase wires was considerably higher than that for the B2-phase wires. This caused a marked enhancement in the total deformation energy of the R-phase wire, as compared to the B2-phase wire. The effect of strain rate on the tensile behaviour and deformation energies of these materials was also investigated. Except the plateau stress of the tensile curve which was raised for both wires, the B2-phase wires were almost strain-rate-independent, whereas the R-phase wires were significantly influenced by the variation in strain rate.
Deformation energy of NiTi shape memory wires
Research highlights ► Deformation energy of B2 and R phase NiTi wires was studied by the MTT method. ► Superelastic energy for B2 wire was higher than the shape memory energy for R wire. ► The secondary elastic energy of was marginally higher for the B2-phase wires. ► Strain rate had little effect on the deformation energies of the B2-phase wires. ► The energy components of the R-phase wires were improved by increasing strain rate.
Abstract Deformation energy of NiTi wires with B2 and R phases was studied by the multiple tensile testing (MTT) method. In traditional materials, the total energy required to tear specimens is assumed to be the sum of elastic, uniform plastic, and post-uniform or tearing energy components. For the shape memory alloys, however, this classification is not valid due to their unusual superelastic/shape memory characteristics. Using a modified MTT method, different energy components were calculated by plotting different combination of deformation energies divided by the specimen cross-sectional area against the gage length of the specimens. The slope of the obtained straight line demonstrates the summation of the elastic, superelastic/shape memory, second elastic, and plastic energy per unit volume and its intercept gives the value of tearing energy. It was found that the uniform plastic energy per unit volume for the R-phase wires was considerably higher than that for the B2-phase wires. This caused a marked enhancement in the total deformation energy of the R-phase wire, as compared to the B2-phase wire. The effect of strain rate on the tensile behaviour and deformation energies of these materials was also investigated. Except the plateau stress of the tensile curve which was raised for both wires, the B2-phase wires were almost strain-rate-independent, whereas the R-phase wires were significantly influenced by the variation in strain rate.
Deformation energy of NiTi shape memory wires
Akhlaghi, M. (author) / Mahmudi, R. (author) / Nili-Ahmadabadi, M. (author)
2010-12-01
8 pages
Article (Journal)
Electronic Resource
English
Deformation energy of NiTi shape memory wires
| British Library Online Contents | 2011
Thermomechanical model for NiTi shape memory wires
| British Library Online Contents | 2010
Structural fatigue of pseudoelastic NiTi shape memory wires
| British Library Online Contents | 2004
Impact protection behavior of NiTi shape memory alloy wires
| British Library Online Contents | 2017
Melting and Fabrication of NiTi Shape-Memory Alloy Wires
| British Library Online Contents | 2002