Strain rate effects on the localization of the stress-induced martensitic transformation in pseudoelastic NiTi under uniaxial tension, compression and compression–shear

Elibol, Cagatay; Wagner, Martin F.‐X.

doi:10.1016/j.msea.2015.07.039

Cited by 54 publications

(35 citation statements)

References 31 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The mechanical response of NiTi subjected to simple compressive loading is quite different [7,8,15,16,17]. While a constant stress plateau in the stress–strain curves is clearly associated with the stable propagation of martensite bands in tension, the macroscopic deformation of polycrystalline SMAs in compression proceeds homogeneously, and no flat stress plateau is observed [18].…”

Section: Introductionmentioning

confidence: 99%

“…The tension compression asymmetry and the pseudoelastic hysteresis led to interesting strain/phase distributions under more complex load cases, such as bending [19,20,21], bending rotation [3,22], or combinations of torsion and tension [12,23,24]. In recent works [7,8], we have also demonstrated that localized deformation is not necessarily limited to tensile loading alone—compression-shear loading (i.e., a combination of predominantly compressive loading with a certain amount of superimposed shear stresses) can also lead to a localization/inhomogeneous distribution of the SIMT. These studies have highlighted that a careful analysis of local strain fields is required to fully characterize the complex material response of NiTi SMAs to these different load cases.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Virtual Extensometer Analysis of Martensite Band Nucleation, Growth, and Strain Softening in Pseudoelastic NiTi Subjected to Different Load Cases

Elibol

Wagner

2018

Materials

View full text Add to dashboard Cite

Pseudoelastic NiTi shape memory alloys exhibit different stress–strain curves and modes of deformation in tension vs. compression. We have recently shown that under a combination of compression and shear, heterogeneous deformation can occur. In the present study, we use digital image correlation to systematically analyze how characteristic features of the nominally uniaxial engineering stress–strain curves (particularly the martensite nucleation peak and the plateau length) are affected by extensometer parameters in tension, compression, and the novel load case of shear-compression. By post-experimental analysis of full surface strain field data, the effect of the placement of various virtual extensometers at different locations (with respect to the nucleation site of martensite bands or inhomogeneously deforming regions) and with different gauge lengths is documented. By positioning an extensometer directly on the region corresponding to the nucleating martensite band, we, for the first time, directly record the strain-softening nature of the material—a specific softening behavior that is, for instance, important for the modeling community. Our results show that the stress–strain curves, which are often used as a basis for constitutive modeling, are affected considerably by the choice of extensometer, particularly under tensile loading, that leads to a distinct mode of localized deformation/transformation. Under compression-shear loading, inhomogeneous deformation (without lateral growth of martensite bands) is observed. The effects of extensometer gauge length are thus less pronounced than in tension, yet systematic—they are rationalized by considering the relative impact of differently deforming regions.

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Virtual Extensometer Analysis of Martensite Band Nucleation, Growth, and Strain Softening in Pseudoelastic NiTi Subjected to Different Load Cases

Elibol

Wagner

2018

Materials

View full text Add to dashboard Cite

show abstract

“…During superelastic deformation of conventional shape memory alloys (SMAs), such as NiTi [13,14], the saturated S-S plateaus are usually observed, which is attributed to that the critical stress required for martensite nucleation is higher than the driving force for growth of martensite variants. Moreover, under the reversible SE, if loaded again, the SMAs show repeatable S-S curves [15,16].…”

Section: Introductionmentioning

confidence: 99%

In-situ TOF neutron diffraction studies of cyclic softening in superelasticity of a NiFeGaCo shape memory alloy

Yang

Chen

et al. 2017

Materials Science and Engineering: A

View full text Add to dashboard Cite

Real-time in-situ neutron diffraction was conducted during uniaxial cycling compression of a Ni 49.3 Fe 18 Ga 27 Co 5.7 shape memory alloy to explore the mechanism on its superelasticity at room temperature, which was manifested by the almost recoverable large strains and the apparent cyclic softening. Based on the Rietveld refinements, the real-time evolution of volume fraction of martensite was in-situ monitored, indicating the incremental amount of residual martensite with increasing load cycles. Real-time changes in intensities and lattice strains of {hkl} reflections for individual phase were obtained through fitting individual peaks, which reveal the quantitative information on phase transformation kinetics as a

show abstract

“…Because of a strong coupling between stress and temperature in the thermodynamic phase stability criterion (Clausius-Clapeyron type), the work also showed strong dependence of localization pattern (number of bands) on deformation rate. The dynamics of formation, propagation and coalescence of transformation bands and the relation to the strainrate was further studied by an in-situ infrared camera in [12,13] or by digital image correlation (DIC) method in [14]. Next, we restrict the review to quasistatic experiments (low loading rates, close to isothermal conditions) in which the influence of the transformation heat to the localization process is minimized.…”

Section: Experimental Observationsmentioning

confidence: 99%

Experimental Observations and Modeling of Localization in Superelastic NiTi Polycrystalline Alloys: State of the Art

Frost

Sedlák

Zineb³

2018

Acta Phys. Pol. A

View full text Add to dashboard Cite

We briefly review the recent experimental and theoretical research on the modeling of localized deformation in NiTi shape memory alloys. These alloys exhibit a remarkable response to mechanical loading with a relatively large reversible strains called superelasticity. We point up factors affecting formation, topology and propagation of localization patterns. These factors bring considerable difficulties to the development of constitutive models and superimpose with theoretical and practical issues related to the modeling of material instability. Some of the models are briefly introduced with a particular attention paid to characteristics of underlying theoretical frameworks.

show abstract

Strain rate effects on the localization of the stress-induced martensitic transformation in pseudoelastic NiTi under uniaxial tension, compression and compression–shear

Cited by 54 publications

References 31 publications

Virtual Extensometer Analysis of Martensite Band Nucleation, Growth, and Strain Softening in Pseudoelastic NiTi Subjected to Different Load Cases

Virtual Extensometer Analysis of Martensite Band Nucleation, Growth, and Strain Softening in Pseudoelastic NiTi Subjected to Different Load Cases

In-situ TOF neutron diffraction studies of cyclic softening in superelasticity of a NiFeGaCo shape memory alloy

Experimental Observations and Modeling of Localization in Superelastic NiTi Polycrystalline Alloys: State of the Art

Contact Info

Product

Resources

About