复合材料高温冲击三维全场动态变形检测方法研究

Research on the mechanical properties of C/C and C/SiC composite materials at high-temperature and high-strain-rate coupling conditions is very important. There are some problems for the traditional measurement methods: speckle patterns at high-temperature and high-strain-rate cannot be made, the accuracy of 2-d measurement is low, and the correlation of deformations is weak. In this project, the plasma spraying technology is used in the speckle preparation to make the sprayed patterns can be existed stably in the deformation environment; the wavelet-package method is used to reduce the noise of the images in the process of the image correlation and improve the accuracy of measurement; the model of the distortion of telecentric lens is presented and the 3-d measurement can be realized with the calibration based on this model. Through the above researches, it is provided technical support by the realization of the C/C and C/SiC composite material at high-temperature and high-strain-rate deformation measurement.

对于C/C及C/SiC等复合材料和结构在高温、高应变率耦合条件下的力学性能研究对于航空航天、国防军工等领域的发展具有重要的作用。传统的数字图像相关方法面临高温高应变率散斑无法制备、二维测量精度偏低和高温高应变率散斑弱相关等问题的挑战，难以实现高温高应变率变形的三维动态变形检测。本项目将等离子喷涂技术与散斑制备方法相结合，研究高温高应变率散斑制备方法，实现高温高应变率变形环境中散斑的稳定存在；将小波包滤波技术与图像相关匹配相结合，研究高温高应变率散斑图像噪声特性，有针对性地进行滤波降噪和图像增强，提高图像相关匹配的精度和稳定性；基于远心镜头成像原理的研究，构建远心镜头成像畸变模型，实现远心镜头的标定从而进行三维全场的变形检测。通过以上系统的研究，实现了C/C及C/SiC等复合材料高温高应变率三维全场动态变形检测，为航空航天、爆炸力学等领域的研究提供了技术支撑。

本项目紧紧围绕数字图像的C/C及C/SiC等复合材料及结构的高温冲击动态变形三维全场检测展开研究，针对航空航天飞行器中所遇到的材料和结构的高温动态变形问题，将高温冲击动态耦合变形的检测温度提升至1800℃，应变率大于100/s，进一步研究了高温冲击动态变形检测机理，提出了新的高温冲击动态数字图像变形检测方法，实现了光噪声滤波降噪及图像去模糊处理方法，为材料和结构在高温冲击动态变形条件下的力学性能研究，尤其是超高音速飞行器和航天飞行器中的结构热冲击动态变形研究提供检测手段支撑。