We make use of a micromechanical energy estimate proposed in the companion paper (Peigney, 2023) to study strain Lüders-like localization in polycrystalline NiTi specimen under tension. Under the assumption that only the most favorably oriented martensitic variant is active in each grain, it is shown that the homogeneous equilibrium problem can be solved analytically for fiber textures (as commonly found in drawn wires or tubes) and more generally for transversely isotropic textures. This leads to an analytical condition for strain localization that admits an explicit expression in terms of the elastic moduli, the lattice parameters and simple statistical information on the texture. The obtained condition allows one to understand what is distinctive about NiTi compared to other shape memory alloys and why strain localization does not appear in compression. In the cases when strain localization is predicted, several quantities of interest such as the strain gap between initiation of phase transformation and localization, the stress drop at the onset of localization and the inclination of the bands can be derived. The results obtained from the presented analytical solution are compared with numerical simulations performed by taking several active variants in each grain into account and considering imperfect transversely isotropic textures. It is found that the presented analytical solution gives a fairly accurate estimate of the response of 100 (and more)-grain aggregates. Taking several active variants per crystalline orientation does not impact the localization condition significantly but gives values of the strain gaps between initiation and localization that are closer to the experimental values reported in the literature.

我们利用配套论文（Peigney，2023）中提出的微机械能量估计来研究在张力下多晶 NiTi 样品中的应变 Lüders 样定位。在假设每个晶粒中只有最有利取向的马氏体变体活跃的情况下，表明均匀平衡问题可以通过分析解决纤维织构（如拉丝或管中常见的那样），更一般地用于横向各向同性织构。这导致了应变定位的分析条件，该条件允许根据弹性模量、晶格参数和纹理的简单统计信息进行明确表达。获得的条件使人们能够理解 NiTi 与其他形状记忆合金相比的独特之处，以及为什么应变局部化不会出现在压缩中。在预测应变局部化的情况下，可以导出几个感兴趣的量，例如相变开始和局部化之间的应变间隙、局部化开始时的应力降和带的倾斜度。将从所提出的解析解获得的结果与通过考虑每个晶粒中的几个活性变体并考虑不完美的横向各向同性纹理而进行的数值模拟进行比较。结果发现，所提供的分析解决方案对 100 个（及更多）晶粒聚集体的响应给出了相当准确的估计。