Analysis Of Fatigue Property Of Waveguide In Airborne Radar Environment

Waveguide is the conductor of radio waves transmission. It is a kind of high-frequency feeder spreads the radio frequency signal in radar. The feeder system is consisted of waveguides and a series of high-frequency devices and other components. It transmits the high-power electromagnetic pulse from the transmitter to the antenna, and then spread the weak reflected signal from the antenna back to the receiver. Therefore, it is significant to study the fatigue property of the feeder system for the performance and the service life of radar.Based on theoretical and experimental analysis, the present paper develops an analysis of the fatigue property of a typical feeder system. The static strength is simulated for the various waveguides under their working conditions by means of finite element method. The static strength of numerical simulations is verified then by the experiments. The local area where plastic deformation occurred with high probability is also presented for the waveguides. To eliminate the plastic deformation area of the waveguide structures that the numerical results showed, the structure optimization of the waveguide is made. The comparison between the optimized modal and the previous modal under seven different loading conditions shows that the stress of the key parts gets a reduction over 50 percent.Then, the transient dynamic analysis of the optimized feeder structure is conducted by the numerical simulations under the impact test condition, and the spectral analysis of the optimized feeder structure is made. On the numerical results of the spectral analysis, the random vibration fatigue analysis of the feeder structure is obtained by means of the three interval method base on Gaussian distribution and Miner linear fatigue accumulation law. The results show that the optimized feeder structure meets the requirements of fatigue life.Although the object of our research is in only one type of the feeder system in radar, the numerical analysis and experimental methods also can be suitable for the other feeder system in almost any other type of radar. It can play an active role in promoting the improvement of the overall performance of the feeder system.