温振多维应力下航天电磁继电器动态特性和抗振性能研究

Aerospace electromagnetic relays must possess excellent vibration resistance to ensure reliable operation under temperature-vibration combined stress conditions. However, existing analyses of the vibration resistance of relays primarily focus on the contact system or the entire device under normal temperature and open-circuit conditions. There is a lack of studies on relays' dynamic characteristics and vibration resistance during closing operations under multi-dimensional thermal and vibrational stress. This paper establishes a digital prototype model with multiphysics coupling of an aerospace electromagnetic relay to analyze the relay's dynamic characteristics and vibration resistance. Compared to traditional single-stress environmental testing methods, this evaluation approach considers multi-dimensional thermal and vibrational stress, which reflects the actual operating conditions and better captures the failure mechanisms and modes of aerospace electromagnetic relays. Firstly, a 3D electromagnetic-thermal-mechanical model of the aerospace electromagnetic relay is established using the commercial finite element software Flux to calculate and analyze its dynamic characteristics. Secondly, the finite element software COMSOL Multiphysics® is employed to develop a temperature-vibration model of the relay, obtaining the relay's natural frequencies and acceleration responses through modal analysis and random vibration simulation. During the calculations, indirect coupling simulates the dynamic characteristics in the time domain and random vibrations in the frequency domain by coupling pre-stress and temperature as two variables, thereby achieving multiphysics coupling in the 3D digital prototype model. The effectiveness of the digital prototype model is validated by experimental measurements of dynamic characteristics and failure frequency with the simulation data. Finally, sine vibration and random vibration tests are conducted under different temperature conditions, and the failure mechanism and modes of the aerospace electromagnetic relay are further analyzed. The following conclusions can be drawn. (1) The established 3D digital prototype model can dynamically simulate the dynamic characteristics and vibration resistance of aerospace electromagnetic relays under combined temperature-vibration conditions, with an error margin within 5% compared to experimental results. (2) Due to the influence of temperature and vibration on changes in material properties, aerospace electromagnetic relays exhibit different dynamic characteristics under varying temperature and vibration conditions. In a combined temperature-random vibration environment, the pull-in time of the aerospace electromagnetic relay is extended, and the number of contact bounces increases, severely affecting the reliability of the opening and closing process. (3) Aerospace electromagnetic relays are prone to resonance near their natural frequencies, with a more pronounced effect under random vibrations. In sinusoidal vibration frequency sweep tests, a counterintuitive phenomenon is observed where the failure frequency increases with high temperatures, possibly due to specific material properties or design factors. (4) Compared to single-stress testing methods, the evaluation approach that considers multi-dimensional thermal and vibrational stress closely reflects the relay's actual operating conditions, failure mechanisms, and modes.