Abstract

A combined model of the phase-structural deformation of shape memory alloys is proposed, within the framework of which the inelastic deformation of these materials can change, both due to phase transformations and due to structural transitions. The model of the development of deformations due to the structural transition uses the concept of a loading surface, isotropic and translational hardening, and an associated flow law. The model of deformation development due to thermoelastic phase (direct or reverse) transformations does not appeal to the concept of loading surface, adequately describing the development of phase deformations, which is observed at constant and even decreasing stresses. The model takes into account the experimentally observed effect of the second mechanism on the first (cross-hardening), which consists in the fact that when deformations change due to phase transformation, the radius of the loading surface changes, which determines the deformation process during a structural transition. Within the framework of the model, a number of phenomena unusual for the theory of plastic flow are observed, such as a decrease in the radius of the loading surface, which can occur even with an increase in inelastic deformations, an increase in this radius, including with a decrease in inelastic deformations, a change in the radius of the loading surface in a situation where the point representing stressed state, moves, or even rests in an elastic region.

中文翻译：

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形状记忆合金相结构变形变化的现象学模型

摘要

提出了形状记忆合金相结构变形的组合模型，在这些模型的框架内，这些材料的非弹性变形可能由于相变和结构转变而改变。由于结构过渡而引起的变形发展模型使用了加载面，各向同性和平移硬化以及相关的流动定律的概念。由于热弹性相（正或逆）相变而引起的形变发展模型并不符合加载表面的概念，该模型不能充分描述相形变的发展，在恒定甚至减小的应力下都可以观察到相变。该模型考虑了第二种机制对第一种机制（交叉硬化）的实验观察到的影响，这包括以下事实：当变形由于相变而变化时，加载面的半径会变化，这决定了结构过渡期间的变形过程。在该模型的框架内，观察到了许多与塑性流动理论不同寻常的现象，例如，加载表面的半径减小，即使非弹性变形增加，该半径增大，这种情况也可能发生。包括随着非弹性变形的减少，在代表受力状态的点移动或什至位于弹性区域的情况下，载荷表面半径的变化。