Ambient effect on damping peak of NiTi shape memory alloy

Experimental study on rate dependence of macroscopic domain and stress hysteresis in NiTi shape memory alloy strips

“…As shown in the following, due to the temperature history in loading, the average stress hysteresis starts to decrease with the further increase in strain rate. It is seen that the loading time is much shorter than the characteristic heat convection time ( E16.6 s in the stagnant air [36]), which means that the released latent heat in loading did not have enough time to transfer out to the air. The stress-strain curve, surface morphology, and the temperature field are shown in Figs.…”

“…Further deformation of the martensite was homogeneous without self-heating but required a more rapid increase in stress. The initial unloading was elastic, accompanied by the more or less uniform cooling of the specimen mainly due to the heat convection with the air [36] plus the conduction with the two grips. The stress decreased monotonically (see n, o, p in Fig.…”

“…In recent years, macroscopic transformation domain patterns and stress hysteresis (damping capacity) in NiTi polycrystalline SMAs under mechanical loading [4][5][6][7][8][9][10][11][12][13][14][15][16][17] and their rate dependence [18][19][20][21][22][23][24][25][26][27][28][29][30][31][32] have been observed and studied in mechanical engineering community. Important issues of the rate-dependent material behaviour addressed include (1) rate-dependent domain patterns in different structures (wire, plates, and tubes) [22,24,[29][30][31][32][35][36][37][38]; (2) ratedependent stress relaxation and stress hysteresis in both single and polycrystals [18][19][20][21]23,[25][26][27]…”

Closed-form solutions for inhomogeneous states of a slender 3-D SMA cylinder undergoing stress-induced phase transitions

“…A large number of experiments (He, Yin, Zhou, & Sun, 2010;Shaw & Kyriakides, 1995Sun, Zhao, Zhou, Saletti, & Yin, 2012;Zhang, Feng, He, Yu, & Sun, 2010) on pseudo-elasticity have been conducted on SMA wires at different temperatures under tension. For a class of SMAs (like Ni-Ti) exhibiting strain softening behaviors, the stress-induced phase transitions are realized by nucleation of martensite band in some particular region and subsequent growth along the wire by http://dx.doi.org/10.1016/j.ijengsci.2014.09.002 0020-7225/Ó 2014 Elsevier Ltd. All rights reserved.…”

Finite Element Modeling of A phenomenological Constitutive Model for Super-elastic Shape Memory Alloy and its Application for Preload Process Analysis of Bolted Joint

“…This phenomenon could mainly be expressed as four aspects: the residual martensite strain accumulation, the gradual decrease of transformation stresses, the gradual change of phase transformation modulus, and the gradual decrease of dissipation energy with the cyclic loadings [5,[9][10][11][12][13]. The researches done by [14][15][16][17][18][19][20] show that the mechanical behavior of the alloy is strongly dependent on the loading rate. The non-monotonic relationship can be found between the dissipation energy and the loading rate.…”