疲劳破坏是航空发动机部件失效的主要原因之一，而疲劳小裂纹演化过程在发动机材料疲劳全寿命研究中占有重要地位。本项目从航空发动机材料的疲劳小裂纹高温力学行为研究的需求出发，重点开展基于采样云纹方法的微尺度高温变形场测量技术研究。具体为提出SEM采样云纹高温试件栅制备新工艺，建立试件栅高温SEM图像的畸变模型，发展局部差异化处理的加窗采样云纹方法和子区位相补偿技术，提高SEM采样云纹法高温变形场的测量精度；发展基于SEM采样云纹方法的高温断裂力学参数表征技术，实现电镜高温环境下疲劳小裂纹尖端变形场的精确测量，获得应力强度因子、裂纹张开位移（COD）等关键断裂力学参数并建立疲劳小裂纹扩展模型。通过本项目的研究，将为高温疲劳小裂纹力学行为研究提供新型光力学测量方法和技术。

Fatigue damage is a major reason of the aero-engine components failure. The evolution process of small fatigue cracks plays an important role in the study of the total fatigue life of aero-engine materials. For a better understanding of the high-temperature mechanical behavior of small fatigue cracks in aero-engine materials, this project aims to study micro-scale full-field deformation measurement techniques at high temperature based on the sample moiré method. Specifically, we will propose the novel high-temperature grating fabrication techniques for SEM sample moiré method. In order to improve the measurement accuracy of SEM sample moiré method, new measurement techniques for SEM sample moiré method will be studied. Firstly, the distortion models of high-temperature SEM grating images will be established. And then the windowed sample moiré method for local differential treatment and the phase compensation technique in sub-area will be put forward. Based on the SEM sample moiré method, the characterization techniques for high-temperature fracture mechanics parameters will be developed. By utilizing SEM sample moiré techniques, the deformation fields around the crack tip of small fatigue crack at high-temperature will be measured; the stress intensity factor and crack opening displacement (COD) of small fatigue crack will characterized; on the basis of the relative experimental data, the propagation model of small fatigue crack will be set up. As a result, new photomechanics techniques will be proposed for the study of high-temperature mechanical behavior of small fatigue crack.