Advanced Materials Research Vols. 490-495

Abstract: This paper made the 3D model reconstruction of the J34 turban blade. First, collected rough points cloud data by using visual measuring equipment. Then, smoothed and filtered the point cloud data, took the rational simplification, finished pre-processing the point cloud data. Finally, the Laplacian of Guassian Detection was used for fitting the edge of turban blade, and reconstructed the 3D digital model. The results proved that this method improved smoothness of the model, and reduced time and cost of modeling and machining.

Abstract: The problem of airline maintenance scheduling is considered in this paper. A maintenance-scheduling model that can determine rational maintenance date is established, in this model, while aircraft materials as well as other factors are taken as constraints, and aircraft air-on-ground (AOG) loss is set as goal function. In order to solve the model, Artificial Bee Colony (ABC) algorithm is utilized by setting the appropriate number of the bees, which can find the optimal solution rapidly. Finally, airline’s practical data is applied to validate the feasibility and practicality of the model and ABC algorithm.

Abstract: Rich phenomenology is generally expected if the heavy neutrinos responsible via the seesaw mechanism for the small neutrino mass observed in neutrino oscillations are not much heavier than the electroweak scale. A model with this feature built in has been suggested recently by Hung. We analyze the lepton flavor structure in gauge interactions and calculate the branching ratios for the rare decays due to the gauge interactions in this model.

Abstract: In this paper, a three-dimensional probabilistic approach for MR brain image segmentation is proposed. Based on the noise-free representative reference vectors provided by SOM, the results of the 3D-PNN method are superior to other traditional algorithms. In addition to the 3D-PNN architecture, a fast three-step training method is proposed. The proposed approach also incorporates structure tensor to find appropriate feature sets for the 3D-PNN with respect to resulting classification accuracy. Computational results with simulated MR brain images have shown the promising performance of the proposed method.

Abstract: The fatigue damage test of metal rubber vibration isolator is performed, the result of which shows that fatigue damage performance of metal rubber is different from conventional solid materials. The damage of metal rubber which is accumulated with its inner partial broken and wore wires, results in deterioration of its macro-mechanical characteristic, macro-cracking and final fatigue failure, so it does not rupture as sudden failure of solid material. It is difficult to describe damage evolution of metal rubber in the microscopic perspective, and from a macro point of view, it is feasible method to describe degree of fatigue damage which bases on the changes of mechanical properties. In order to reflect the incremental cumulative damage degree of metal rubber, the stiffness damage and damping damage are used to accurately describe the fatigue damage process of metal robber, and the comprehensive damage factor is proposed to be the fatigue failure criterion. Damage factor can predict fatigue life of metal rubber specimen accurately, so it has reference significance to design of metal rubber

Abstract: Aircraft ground icing can result in decreasing the stability of the aircraft at or shortly after take off.. A theoretical model for frost formation by water vapor on aircraft in atmospheric air has been presented in this study. Frost surface temperature and frost thickness can be obtained by the model. Effects of aircraft surface temperatures and air conditions, such as aircraft surface temperature, air temperature and air velocity on the frost surface temperature and frost thickness can be evaluated by using this model. It revealed that the surface temperature increases with the surface temperature, the air speed and air temperature. The frost thickness increases with the air speed and the air temperature, decrease with the surface temperature.

Abstract: Auto-targeting fire sprinkler system is an intelligent fire extinguishing equipment that used in interior large space. An auto-targeting fire sprinkler system was designed; the compositions and working principle were also expounded in detail. The water trajectory equation was deduced and simulated by Matlab software according to the principle of particle kinematics, ballistics, and fluid mechanics. The relationship among working pressure, pitch angle, installation height and jet range, flow landing speed was analyzed. The results show that the fire sprinkler system can satisfy the design requirements, and the water trajectory equation basically concides with the actual situation, which can provide some theoretical references for the fire precision location.

Abstract: The maintenance and management of civil aero-engine require advanced monitor schemes to evaluate aero-engine health and condition in order to ensure safety of aircraft and increase life of aero-engine. In this paper, we adopted Kalman filter approach to monitor an aero-engine health and condition by building prediction models of main aero-engine performance parameters (EGT, N1, N2 and WF). The AR model is introduced into the Kalman filter equations, which is a helpful technique to improve the accuracy of monitoring models of performance parameters. When the relative error goes beyond ±0.3%, alarms will be given. The prediction results show that Kalman filter theory using for AR regression prognostic is an effective approach in aero-engine monitoring.

Abstract: The digital filter is one of the most significant applications of digital signal processing (DSP). The design process is very complex involving the model approximation, parameter selection, computer simulation and a series of work. This paper introduces an efficient design method for the digital filter (IIR and FIR) based on the Signal Processing Toolbox of MATLAB, which makes design easy, fast and greatly reduces the amount of design work, and then proves it by practical examples.

Abstract: The max stress is lying on the joint point of the carrier and planetary gear shaft because of the bending deformation of the shaft. The paper mainly introduces a method to analyze the automobile engine failure combining probability causal model and genetic algorithm. This method can quickly and accurately diagnose the complicated problems and troubles. And we have applied this kind of method into finding and diagnosing automobile engine failures and achieved a better results and effects. At the same time, it has also indicated that genetic algorithm works well in automobile failure diagnosis.