Simulation of the Response and Evolution of Localization in Pseudoelastic NiTi Tubes Under Biaxial Stress States
Simulation of the Response and Evolution of Localization in Pseudoelastic NiTi Tubes Under Biaxial Stress States
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DOI：
10.1016/j.ijplas.2021.103179
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发表时间：
2021-12
影响因子：
9.8
通讯作者：
Karlos Kazinakis;S. Kyriakides;C. Landis
中科院分区：
文献类型：
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作者：
Karlos Kazinakis;S. Kyriakides;C. Landis
由几乎等原子NiTi表现出的众所周知的拉伸/压缩不对称性先前已经使用压缩的硬化势和拉伸的部分软化势来建模，以表示伪弹性相变（Jiang等人，2016年b）。本研究首先扩展了该本构模型，以包括Bechle和Kyriakides（2016 a）对NiTi管进行的轴向力-内压联合实验中揭示的各向异性。然后重新校准该模型，在管的有限元分析中实施，并用于模拟整个范围内的双轴实验。总的来说，模拟再现以及应力平均应变的应变曲线和转换应力位点，而环向主导应力路径的转换应变的程度有点过度预测。局部化的演变形式的高或低应变螺旋带，螺旋角的变化相对于应力比，和耗散能量比较有利。再现了等双轴应力状态附近的硬化响应和基本均匀的变形，但硬化程度降低，不均匀性轻微。尽管有一些微小的差异，结果表明，在再现的现象丰富的行为表现出的管状镍钛合金结构双轴载荷下的分析的整体成功。
The well-known tension/compression asymmetry exhibited by nearly equiatomic NiTi has been previously modeled using a hardening potential for compression and a partially softening one for tension to represent pseudoelastic phase transformations (Jiang et al., 2016b). The present study first extends this constitutive model to include anisotropy revealed in the combined axial force-internal pressure experiments on NiTi tubes of Bechle and Kyriakides (2016a). The model is then calibrated anew, implemented in a finite element analysis of tubes and used to simulate the entire range of biaxial experiments performed. Overall, the simulations reproduce well the stress-average strain hystereses and the transformation stress loci, while for hoop dominant stress paths the extents of the transformation strains are somewhat over-predicted. The evolution of localization in the form of high or low strain helical bands, the variation of helix angles with respect to the stress ratio, and the dissipated energy compare favorably. The hardening response and essentially homogeneous deformation exhibited in the neighborhood of the equibiaxial stress state is reproduced, but with reduced hardening and mild inhomogeneity. Despite some minor differences, the results demonstrate the overall success of the analysis in reproducing the phenomena-rich behavior exhibited by tubular NiTi structures under biaxial loadings.