基于原位测定的NiTi记忆合金相变塑性的非均匀多场复杂行为研究

NiTi shape memory alloy is the most typical Shape Memory Alloys, The phase transformation plasticity in NiTi alloys, such as plastic slip and twinning, the Transformation Induced Plasticity and other complex behavior, is one of the front and hot field in academic research. The material behavior of SMA is involved in both temperature and load changing, while the extensive experimental and theoretical work developed in the past have focused on the homogeneous mechanical response and traditional measurements of SMAs. Considering these disadvantages, the in situ multi-physical field investigation on the influence of plasticity in transformation instability and localization could be used in this proposal project. It could focus on study of the sophisticated behavior changing by non-homogeneous fields (the rate of strain and temperature fields), and the complex constitutive relation of NiTi shape memory alloys could also be modeled. Meanwhile, In view of engineering applications, the material instability as the function material and the fatigue reliability as structural materials in SMAs would be studied, and a typical application would also be carried out. This project could be possible to provide a solidity foundation to completely and accurately reveal the law of transformation plasticity in NiTi Shape Memory Alloys, and provide reliable analytical methods and tools for practical engineering applications of NiTi shape memory alloys.

NiTi形状记忆合金是最典型的SMA(Shape Memory Alloy)材料，具有相变诱导塑性以及塑性滑移和孪晶等复杂的相变塑性行为，是目前学术界研究的前沿与热点领域之一。SMA材料的行为特征涉及温度变化及外场载荷的作用，目前的研究还限于仅考虑均匀载荷或非全场作用下实验与理论分析。本申请项目针对这些不足，采用多场原位测量的先进实验手段来测定和研究SMA复杂塑性行为对相变失稳与局部化的影响规律，重点针对非均匀多场(应变场、温度变化率)作用下的复杂行为开展研究，并获得NiTi记忆合金的复杂本构关系；考虑实际工程应用的背景，还研究SMA作为功能材料的稳定性问题以及作为结构材料的疲劳可靠性问题，研究高精度的数值模拟方法，并针对工程实例开展典型的应用研究；本项目为完整、准确地获得NiTi记忆合金相变塑性的规律打下坚实的基础，为NiTi记忆合金的实际应用提供实用、可靠的分析方法和工具。

NiTi形状记忆合金是最典型的SMA(Shape Memory Alloy)材料，具有相变诱导塑性以及塑性滑移和孪晶等复杂的相变塑性行为，是目前学术界研究的前沿与热点领域之一。SMA材料的行为特征涉及温度变化及外场载荷的作用，目前的研究还限于仅考虑均匀载荷或非全场作用下实验与理论分析。本项目采用多场原位测量的先进实验手段来测定和研究SMA复杂塑性行为对相变失稳与局部化的影响规律，重点针对非均匀多场(应变场、温度变化率)作用下的复杂行为开展研究，并获得NiTi记忆合金的复杂本构关系；系统研究NiTi记忆合金在循环载荷下的相变诱导塑性与局部变形场特征，还针对SMA材料的数值模拟方法及有限元模拟控制研究；本项目为完整、准确地获得NiTi记忆合金相变塑性的规律打下坚实的基础，为NiTi记忆合金的实际应用提供实用、可靠的分析方法和工具。