Research On Test Method Of Burning Surface Retreat State Of Solid Rocket Motor Based On Microwave CT

The test and analysis of the retreating process of the burning surface of the grain is of great significance to the evaluation of the missile performance and the damage effect.At present,the existing burning surface retreat test method has the problems of long test period and large error in calculating the burning surface of complex charges,which results in poor supportability of the obtained test data.The emergence of non-destructive testing methods provides new research ideas for burning surface retreat testing,but the existing non-destructive testing methods such as X-ray and ultrasound are limited by the testing process,equipment installation,testing efficiency,and cannot obtain dynamic images of the burning surface retreat process,the microwave can be deployed through multiple points and through a single transmission and multiple reception mechanism to achieve fast CT imaging of the microwave field.Therefore,based on the principle of microwave imaging,this paper studies the microwave CT-based image reconstruction algorithm for burning surface retreat,which can meet the dynamic testing requirements of the burning surface retreating process of solid rocket motors.Based on the principle of radiographic imaging,the thesis first established a mathematical model of the burning surface retreat based on microwave CT,and studied the projection matrix characterization algorithm for microwave CT reconstruction based on the microwave propagation path,and used the improved ART-TV algorithm to reconstruct the burning surface moving images that change back.Secondly,the microwave wavelength is longer,and there are diffraction and scattering effects when interacting with the object to be measured.It is simply regarded as a ray model,and the quality of the reconstructed image is poor.In response to this problem,the paper replaced the ray model with a Gaussian beam model,studied the microwave CT reconstruction algorithm based on the Gaussian beam model,and improved the traditional TVAL3 algorithm.Finally,the above methods are verified through simulation experiments.The experimental results show that the microwave CT imaging method studied in this paper can effectively characterize the change of the burning surface of the solid rocket motor,and the reconstruction error of the burning surface with a diameter of 10 mm ~ 159 mm is less than 1mm,and the reconstruction accuracy of the improved TVAL3 algorithm is increased by 57%,which in turn can provide theoretical support for the design and verification of actual experimental test systems.