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Based on the theories of rotor dynamics, a dynamic model of rotating blade was built. Taking account of the effect of spin softening, the research on vibration characteristics of high-speed rotating blades was carried out under different speeds. The results had shown that frequency of blade vibration increased with rising rotating velocity, whilst the frequency of all orders declined with the influence of spin softening. Meanwhile, the change of each mode shape of blade was not very large at different speed. The conclusion derived from this paper had both theoretical and empirical value on retrofitting, optimal-designing, as well as engineering application for high-speed rotating blades.

To realized the parametric design of automobile synchronizer ring spline tooth efficiently, a method is presented in this article, which is realized based on the UG secondary development tools. The user environment settings and the establishment of the menu file and the human-computer interaction window are introduced in detail. The programming language is written to realize the parametric design of the spline tooth of synchronous ring. Application result shows that the method simplifies the synchronous ring modeling process and improves the working efficiency.

In this paper a new method is proposed for intelligent sort of battery from waste paper based on Invariant Moments and Fractal Dimension (IMFD). In IMFD, a new distinctive feature that based on the edge contours is extracted to describe the target picture. At first invariant moments technique is used to extract Hus seven moments as the global descriptors from the target image. Then the fractal dimensions are extracted as local invariant descriptors by using Fractal Dimension. At last, a combing descriptor is built according the distinctive feature, which combines the global descriptor and the local descriptor together. The features are highly distinctive, and can be matched with high probability against a large database of features. The practical tests performed in this article show that the proposed method has a significant effect on increasing the stability, the accuracy of classification, and also can effectively against the huge-information during the image processing.

Work-hardening of machined surface plays an important role in the evaluation of surface quality and performance of wear resistance in the process of machining components. In this study work-hardening of machined surface during milling 7050-T7451 aluminum alloy is investigated using micro-hardness experiments under different cutting conditions. Moreover, the wear resistance of machined surface including wear quantity and friction coefficient are obtained and studied by means of high speed ring-block friction-wear tester. The work-hardening and wear resistance are particularly sensitive to cutting speed. Friction coefficient has marked drop trends and the tendency of wear quantity is ascend in first and descend at last as work-hardening increases. The comparison of wear resistance under different cutting conditions shows that the wear resistance of machined surface can be directly affected by work-hardening and machined surface obtained by high speed milling with higher micro-hardness have more superior in wear resistance performance.

In order to solve the forming defects in the steel ball cold heading process, a novel force sensor which chooses the PVDF piezoelectric films as force-sensing elements is designed. The advantages and disadvantages of piezoelectric force sensor on measurement of the cold heading force are compared with existing force sensors. By using FEM, sensor’s linearity and the structure size are analyzed. Compared with the traditional sensor, this structure is more reasonable. The presented PVDF piezoelectric force sensor has wide frequency range, good dynamic performance, and can realize dynamic measurement.

The large-scale and modular design of vibrating screen brings about the trend that the screen separate from screen frame. The separation of the screen frame and the screen changes their dynamic characteristics. By making modal analysis and harmonic response analysis in ANSYS, the dynamic data of the screen and the screen frame was obtained, such as the natural frequencies, mode shapes, stress distribution and strain distribution. The results show that the stiffness of screen frame is higher than stiffness of the screen and the side plats and beams of screen are the weak parts.

However three-body vibrating screen is widely used in engineering practice, many dynamics of it have not well been addressed. For studying three-body vibrating screen dynamics, the vibrating screen dynamic model and the virtual model were established. Through deriving the dynamic equations and simulating the vibrating screen start - running process, the analytical equations and the trajectories were obtained. Studies have shown that the VBVS vibration in the Z direction is complex and the X direction which perpendicular to the axis of exciters is the sensitive direction for the installation error. In addition, the SBD’s trajectories in the direction which does not exist exciting force are superimposed by the trajectories of USB and LSB.

Isometric modification, as a new modification method of spur bevel gear was proposed. Based on the gear geometry theory and the normal meshing motion equation of gear pairs, changes of meshing points and angles are analyzed and the effect of axial modification on gear pair meshing movement is discussed, and then dynamics emulation analysis was operated with FEA software, the results show that the stress distribution of gear surface was controlled by isometric modification, the load concentration, agglutination and pitting of the gear can be avoided effectively.

Mechanical fatigue experiments are performed for piston pin seat, and the stress-strain response of the piston overall structure is analyzed by the elastic-plastic FEA. An estimated formula of the fatigue life is put forward by amending the Manson-Coffin formula on the basis of studying the fatigue behavior of piston pin seat. The Newton iterative algorithm is applied to calculate the modified formula, and the mechanical fatigue life of piston pin seat is obtained. By comparison the predicted value with the experimental results, the feasibility of estimated formula is validated.