High Temperature Transient Strain Measurement and Crack Fault Analysis of the Engine Tail Nozzle Regulating Plate

The regulating plate of the tail nozzle of a certain engine is a thin-walled structure, which will be subjected to high-temperature and high-speed gas erosion during operation. When working under high load conditions, large-scale crack damage and block falling occur. In order to analyze the cause of the fault, high-temperature strain and temperature measurements were carried out on the regulating plate of the tail nozzle. Conduct finite element analysis to obtain the natural frequency, vibration mode, and basic strain distribution of the tail nozzle adjustment plate, and determine the position of the high-temperature strain measurement point based on simulation calculation results. The laboratory conducted transient strain thermal effect tests on the tail nozzle regulating plate to obtain the thermal strain change curves of the tail nozzle regulating plate under different temperatures and heating rates. Based on the strain and temperature data of the tail nozzle regulating plate during engine operation, as well as the thermal effect curve of the tail nozzle regulating plate obtained from the experiment, the transient high-temperature strain of the tail nozzle regulating plate was calculated. By conducting statistical and spectral analysis on high-temperature strain data, the strain characteristics of the tail nozzle adjustment plate are analyzed, and based on this, the possible causes of crack damage are analyzed.