Advanced Materials Research Vols. 945-949

Abstract: The Qinghai-Tibet highway subgrade inhomogeneous deformation is very serious because of the bad climate environment and the special engineering condition of permafrost. To reveal the mechanism of subgrade diseases, based on the theory of elastic-plastic deformation, the control equation of the stress and deformation field of the subgrade is established. We analyze subgrade stress and deformation field by finite element software. Considering effect of the southern and northern slopes, the model of the inhomogeneous deformation of the subgrade was established. Then we calculated the variation characteristic of the lateral inhomogeneous deformation under different melting depth. The results showed that the melting interlayer, melting depth and the effect of southern and northern slopes were the key factors influencing the permafrost subgrade lateral inhomogeneous deformation.

Abstract: The single screw mathematical model is established based on dynamics analysis, and the numerical simulation and optimization design is analyzed. Through the virtual assembly simulation and digital assembly experiments on the single screw, to obtain the compatibility of the improved single screw structure. Thereby, the matching and assembly interference of model design is tested, to optimize the improved single screw compatibility between the stator and rotor, and the device is achieved a dynamic interactive digital assembly in virtual reality environments.

Abstract: Virtual maintenance technology is a major innovation in the equipment maintenance field in recent years, the armored anti-riot vehicles play a vital role in the tasks of the duty, conflict, terrorism of the armed police force. In order to apply the virtual maintenance technology in armored anti-riot vehicles better, the article introduced the virtual maintenance technology and its key technologies, and gave the importance of virtual maintenance technology. It established the virtual maintenance process model of armored anti-riot vehicles. At last, it gave the prospect of the technology and made some suggestions.

Abstract: Plane-generated double enveloping hourglass worm pair has unique characteristics of double contact line; it has the advantages of wide tooth working area, large bearing capacity, and long service life, etc. However, its development has been restricted by such factors as difficulty in measuring, worse processing precision, etc. In this article, a modeling approach is presented in order to obtain the meshing point’s coordinates of the plane–generated enveloping hourglass worm based on theoretic analysis and computer-aided design principle. And a measuring equipment system is designed to measure the meshing point’s coordinates. Key errors of this worm have been discussed and obtained by comparing the theoretic coordinates and the measuring coordinates. Finally, an experimental study has been carried out to validate the modeling method and measuring equipment system.

Abstract: Aiming at the existence problems of surface fitting on the current surface measurement method of digital characterization of engineering surfaces, the Pro/E software is used to envelope processing on measured data which is reduced noise and volume, and formed of small plane characteristics. Then the small plane is fitted based on bi-cubic B-spline algorithm and generated entity. A finite elements contact model of engineering surface and the rigid plane is established. And then the relationship of real contact area with the change of load with different material parameters is proposed. Generally, comparison between computed and previous studies’ results showed good agreement, which lays a foundation for the next step of study on the influence of the repair assembly performance upon mechanical joint surfaces and has a certain engineering significance.

Abstract: The port section intersecting lines of circular-pipes are complicated space curves in multi-pipe intersecting structures, which makes it is difficult to treat circular-pipes for packing pipe precisely by traditional algorithm. A new decoding algorithm is proposed by dividing and translating points of intersecting lines in pipes’ port sections and calculating the least surrounding boxes of them. Encoding and decoding method and evaluation mode of fitness function are given. And responding packing module based on this decoding algorithm is developed in AutoCAD. It demonstrates that using the decoding algorithm can improve the utilization rate of materials and make programming efficient and easy.

Abstract: The method of Fuzzy Synthetic Evaluation is presented to optimize oil-water separator design in the paper. Firstly, the key design parameters to be optimized are determined. Secondly, the CAD technology is applied to achieve parametric models of separator and the CFD technology is employed to fulfill fluid simulation of separator parametric models. Then, with the evaluation indexes established, the simulation results of each separator parametric model are evaluated by Fuzzy Synthetic Evaluation. Finally, by comparing the evaluation value of every parametric model, the optimal design model of oil-water separator is achieved.

Abstract: This paper focuses on the study on the installation angle of the adjustable movable blade axial flow fan.At first, the airfoil and the corresponding series of fan is selected, and detailed calculation of the blade section is performed to obtain the chord length and the thickness of the fan airfoil at different circumferential surfaces, as well as the coordinate value of each section. Then, a three-dimensional solid modeling of the fan with different installation angles in Pro/E is used for mesh generation and boundary conditions arrangement in Gambit. Finally, an analogue simulation is carried out in fluent to analyze the velocity of the blade, the backpressure and turbulence generated by the airflow on the blade.

Abstract: Hydroelectric generating sets of a hydropower station have emerged a serious problem of abnormal noise in the Chinese southwest. To analyse the low-frequency characteristic of noise, a noise test was done in the power station site, and the noise of different working conditions was recorded. After the spectral analysis, the average dominant frequency and average loudness of noise were got, it is the basis of subsequent analysis and research. This article has some reference value in the noise monitoring and diagnosis.

Abstract: The virtual experiment for development of local shockwave, which is one of a series of virtual experiment software that have been accomplished based on numerical simulation and modern computer technologies by the authors, was taken as an example, the design principles, modules constitution, developing tools, and experiment courses were introduced. It is of practical significance on how to make use of virtual experiment technology to reform practical teaching and enhance energy efficiency ratio of experimental teaching.