A novel deformation measurement method for ablation materials in combustion and ablation process

Ablation material is at the base of the entire aerospace industry. The ablation process is the primary mechanism of thermal protection provided by the ablation material. The mechanical performance of ablation materials across the ablation process is a significant problem for the ablation material research. The combustion phenomenon in the ablation process leads to the failure of the measurement of mechanical properties of materials in the ablation process, which limits the study of mechanical properties of ablation materials. In this paper, a method for the thermo-mechanical coupled deformation measurement is presented. Through the use of filter and light source with a specific wavelength, the high-temperature deformation process of the ablation material specimen from room temperature to 2300K is measured accurately. A new method of speckle feature change matching is presented. The convolution neural network is used to establish the corresponding matching and parameter model between the feature changed speckle feature and the initial speckle feature. The DoG values replace the traditional gray-scale feature for the correlation matching, and the continuous thermo-mechanical coupling deformation of ablation materials is carried out through simulation experiments and actual experiments. The experimental results show that the proposed method can be used to measure and analyze the strain of ablation materials in the process of high-temperature continuous thermo-mechanical coupling deformation.