空间相移剪切散斑干涉术动态微应变测量理论及关键技术的研究

With the rapid development of the domestic aerospace and advanced manufacturing, the demands of product quality and reliability has yielded the need of highly efficient methods for dynamic strain measurement which should be full-field and non-contact. However, so far this issue has not yet been fully resolved domestically and abroad. It is also one of the most popular research topics worldwide. This project proposes a novel spatial phase-shift digital shearography based on sole camera and multi-spatial frequency to achieve the precision measurement of full-field dynamic strain distribution. The key innovations of this research include: (1) to achieve simultaneous recording of multi shearograms by a single intensity image based on multi spatial frequency theory; (2) to separate the multi shearograms from the single captured image and to evaluate dynamic strain distribution from the separated shearograms; (3) to experimentally verify the validity of the proposed method and evaluate its measuring accuracy. The successful completion of this project aids in the improvement of the nation wide testing capabilities for novel engineering materials in a variety of complex conditions. The core of that the research results will enable the country in this research area is technically independent intellectual property rights. It will have an important significance for promoting the development and application of dynamic strain measurement.

近年来随着我国航空航天和现代制造技术的迅速发展，对新型工程材料的全场和非接触动态微应变测量技术提出了紧迫的要求，但迄今这一问题在国内及国际上均未得到完全解决。本项目提出一种基于单相机、多空间载波频率的新型数字剪切散斑干涉技术，能够实现全场动态微应变的直接和精密测量。主要研究：（1）实现同步记录多幅剪切干涉图于单一图像的多空间频率数字剪切散斑干涉相关理论和方法；（2）从单一图像分离出多幅剪切干涉相位图的技术， 实现多剪切散斑干涉图相位的同步测量，最终实现微应变的动态测量；（3）实验方法，验证相关理论和方法的有效性并评价其测量精度。本项目的开展有助于提高我国航空航天领域对新型工程材料在各种复杂条件下的测试能力，研究成果将使我国获得该研究领域核心技术的自主知识产权，对于推动动态微应变测量技术的发展与应用具有重要意义。

全场动态微应变的测量在航空航天和先进制造业领域具有重要的应用价值，对关键结构和装备的力学性能评估和寿命预测都有重要意义。数字剪切散斑干涉技术是一种激光应变测量技术，具有全场、非接触和高精度测量的优点。然而传统上该技术难以用于动态测量，也难以实现多维应变的同时测量。本项目深入研究了空间载波数字剪切散斑干涉技术，提出一种基于单相机、多频率空间载波的新型数字剪切散斑干涉技术，能够实现多维动态微应变的全场精密测量。设计了结构简单、鲁棒性高的迈克尔逊型空间载波数字散斑干涉光路，在此基础上提出三色数字剪切散斑干涉测量理论和方法，揭示了频谱分布和相位提取的影响因素，明确了光路参数的优化条件，实现了三维微应变的动态测量。随后进一步提出绝对相位测量方法和双剪切方向测量方法，并提出光路优化方法，进一步提升三色数字剪切散斑干涉方法的测量能力。项目研究成果大幅提升了数字剪切散斑干涉应变测量能力，为工程材料和结构的力学性能评估提供先进的工具，对推动相关领域测试技术的发展具有重要意义。