Study on time-frequency domain characteristics of acoustic emission in thermo-mechanical deformation processes of mechanical seal

Thermo-mechanical deformation constitutes a primary failure mechanism in mechanical seals, necessitating the integration of numerical simulation with dynamic process monitoring. Consequently, a thermo-mechanical coupled numerical model was developed utilising the ANSYS Workbench platform. In conjunction with the simulation, a custom-designed multifunctional test rig for contact mechanical seals was employed to acquire synchronised temperature data, eddy current displacement signals, and acoustic emission (AE) signals under diverse operating conditions. The simulation accuracy regarding thermo-mechanical deformation was substantially optimised by dynamically calibrating boundary conditions via empirically measured temperature data. Subsequent signal processing, employing time-domain and bispectral analysis, isolated critical characteristic frequencies associated with thermo-mechanical taper formation. Experimental results indicate that the dynamic evolution of characteristic frequency amplitudes effectively delineates the progression from initial thermo-mechanical taper nucleation and severe deformation to stable formation. Furthermore, significant variations in thermo-mechanical deformation magnitude and AE signatures were observed across distinct friction pair materials. These findings offer theoretical substantiation for reconstructing end-face macroscopic morphology via temperature inversion, while simultaneously establishing a methodological framework for the application of AE technology in condition monitoring of high-parameter seals.