铁磁形状记忆合金智能复合材料力-磁-热耦合效应机理与力学性能分析

Ferromagnetic shape memory alloy intelligent composites are a new type of functional material. They possess both thermoelastic martensitic transformation and magnetic transition. In addition to the strains induced from temperature or stress controlled conventional shape memory behaviors, large strains can be produced in these composites under the external application of moderate magnetic fields. It is easy to process and less costly. These properties make the composites attractive for a wide range of applications. However, till now some studies for these composites focused on the fundamental stage. And many important properties are not yet investigated in detail. This project will evaluate mechanical-magnetic-thermal behaviors, phase transformation characteristics and its evolution, and mechanical parameters. Based on the micromechanical and the thermodynamic theory, considering anisotropy, magneto-mechanical paths and microstructure, a constitutive model for the composites will be developed. Numerical simulation will be conducted, which can extend this model to complex structure and complex magnetic and mechanical field. By using the proposed model, the effects of the matrix, ferromagnetic shape memory alloy inclusions, temperature, load and magnetic field on mechanical properties of the composites will be analyzed in detail. The proposed work can provide theoretical foundation in designing ferromagnetic shape memory alloy composites．

铁磁形状记忆合金智能复合材料兼具热弹性马氏体相变和磁性转变，可在力、温度和磁场的作用下输出应变，该复合材料制备简单，成本低，抗压强度高，具有广阔的应用前景。然而，迄今为止人们对该材料在力、磁、热耦合作用下的相变机理和力学性能的研究仍处于初步探索阶段，对其本构特性认识尚不够充分。本项目拟对该复合材料在力、磁、热耦合作用下的力学性能进行测试，观察相变微结构特征，分析其细观结构、应力、磁场、温度等因素对材料相变和力学特性的影响，建立相应的定量关系；结合细观力学方法和热动力学原理，考虑材料的各向异性，建立一种能够准确表征材料细观结构和磁力学路径的各向异性本构模型；编制适用于模拟该材料相变机理和力学特性的计算程序，与实验数据进行比较，验证理论的正确性与有效性；在该理论框架下系统地分析基体、铁磁形状记忆合金夹杂、温度、外力和磁场等因素对复合材料力学性能的影响，进而为该材料的优化设计提供理论依据。

铁磁形状记忆合金智能复合材料兼具热弹性马氏体相变和磁性转变，可在力、温度和磁场的作用下输出应变，该复合材料制备简单，成本低，抗压强度高，具有广阔的应用前景。然而，迄今为止人们对该材料在力、磁、热耦合作用下的相变机理和力学性能的研究仍处于初步探索阶段，对其本构特性认识尚不够充分。本项目对铁磁形状记忆合金/环氧树脂复合材料在力、磁耦合作用下的力学性能进行测试，观察相变微结构特征，分析其细观结构、应力、磁场等因素对材料相变和力学特性的影响；结合细观力学方法和热动力学原理，考虑材料的各向同性和各向异性，分别建立了能够相对准确地表征材料细观结构和力磁学路径的各向同性和各向异性本构模型；编制了适用于模拟该材料相变机理和力学特性的计算程序，与实验数据进行比较，验证理论模型的正确性与有效性；建立了该复合材料的有限元模型，对该复合材料的力、磁学行为进行了模拟和仿真。在该理论框架下系统地分析了基体、铁磁形状记忆合金夹杂、外力和磁场等因素对该复合材料力学性能的影响，进而为该类材料的优化设计提供理论依据。