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The traditional method of finite element that fixing constraint between suspension and chassis for the damaged aircraft recovery trailer chassis usually ignored the buffer function of suspension leading to too much stress, So aiming at that problem The constraint of trailer is fixed by the method of balance frame system. Based on FE-software ANSYS the FE module of trailer chassis and balance frame system is set up and their node is coupled by the force analysis of aircraft with half of fuel in damaged. It's result that the maximum stress is less than permissible stress.The result show that the method of balance frame system is more practical by computer simulation.

When different types and extent of faults occurs at transformer winding, the energy of the signals in different frequency bands will change. So it can calculate the characteristic energy of different response signals at different states to determine whether the winding failure. The transformer fault diagnosis method based on FRA and characteristic energy extraction is presented, the maximum cross-correlation between the signal and the wavelet was taken as criterion to choose the wavelet. The method is verified by test. Experimental results show that this method can diagnose winding fault type and extent effectively, and improve the sensitivity of fault diagnosis.

For the purpose of enhance the accuracy and sensitivity of FRA of transformer winding deformation fault diagnose, this paper made several improvements on the traditional FRA. Regarding the signal source's insufficiency, we changed the impulse replaces the sine frequency sweep signal. The test results showed: after the improvement, the test cycle reduces and the signal frequency response range is broader. We also used the FFT and EMD method to improvement the analysis of frequency response curves, this increased the analysis accuracy and diagnose sensitivity, find the fault characteristic. This study can be used on the development of transformer winding fault diagnosis, detection and test methods.

Abstract:The installation of winglet is an important method to reduce the induced drag, but if the winglet design is not good enough will increase weight and drag, and result in reducing the lift-drag ratio of the plane. With the small jets as the research object, referred the wing of "longhorns" to build basic airplane wing, with installation of fusion winglet. According to the 5 parameters of winglet established test models by the use of orthogonal test method, the test models were aerodynamic simulated and analyzed by Fluent, and studied the impact of 5 parameters on the lift-drag ratio. The results showed that: the setting angle has the greatest impact on the aerodynamic performance of winglet, and the model of winglet has better lift-drag characteristic which was optimized by orthogonal test, thus to provide theoretical basis for parametric design of winglet.