Temperature has significant effects on modal parameters of a structure. However, it is difficult to do a full-field dynamic measurement and identify modal parameters of the structure under high temperature and working conditions. In this work, three-dimensional digital image correlation combined with Bayesian operational modal analysis is used to yield a full-field non-contact thermal modal testing technique under ambient excitation. Thermal modal verification experiments are carried out on a titanium plate with free boundary conditions under ambient excitation by a low-cost high-temperature dynamic measurement system. Natural frequencies and mode shapes of the plate under different average high temperatures are studied in detail. From the experimental process, it is believed that the thermal modal testing technique proposed in this work is an effective alternative testing technique to traditional contact testing techniques, and after some improvements, one can achieve thermal modal analysis of a structure under high temperature and working conditions.

温度对结构的模态参数有重要影响。但是，在高温和工作条件下，很难进行全场动态测量并确定结构的模态参数。在这项工作中，三维数字图像相关性与贝叶斯操作模态分析相结合，用于在环境激发下产生全场非接触式热模态测试技术。通过低成本的高温动态测量系统在环境激发下在自由边界条件下的钛板上进行热模态验证实验。详细研究了在不同平均高温下板的固有频率和振型。从实验过程来看