Applied Mechanics and Materials Vol. 487

Abstract: The characteristic of controllable vane damp is about the relationship between choke opening and damp parameter of proportional flow control valve, the relationship between the input current of electromagnet and controllable damp parameter is available after knowing the characteristics of electromagnet. This is the basic of control system design and the central dynamic characteristics of vane damp. The structure of vane damp is analyzed and the flow model is established, to provide the theoretical guidance with the design, analysis and improvement of vane damp, a simple calculating and accurate analytical method is proposed.

Abstract: This article introduces the machining mechanism of rolling process and analyzes its influence on hardness, abrasion performance and fatigue strength of the work piece.

Abstract: In view of the problem that new type crushing ripper installation of tamping equipment in circulation under the action of different load working multiple cases may occur structural fatigue damage, analysis of its force characteristic, establishment ripper rack compression bending component model, according to the working condition of the most unfavorable load combinations, using the allowable stress method to calculate structural fatigue strength; the combined effect of road load spectrum and vibrating load is also taken into consideration, then statics analysis and fatigue analysis of new type crushing ripper are calculated with the finite element analysis software Ansys Workbench. The results show that theoretical calculations are in accordance with the finite element analysis results, it evidences that the fatigue strength analysis method of crushing ripper is feasible and correct. It provides a reference for the anti-fatigue optimization design of new type crushing ripper, to guarantee its meet the operational requirements under of bad conditions.

Abstract: Mechanical parking systems are widely used special electromechanical equipments. With the increasing interests on strength safety, it was becoming a hot spot to achieve its strength properties precisely. Based on Timoshenko beam theory, a mechanical parking system was simplified to a two dimensional model, and strength calculation was performed with analytical method. Furthermore, finite element method was adopted to calculate the strength properties of this mechanical parking system, and the maximum Von Mises and shear stress were approached. By comparison with experimental stress analysis, the finite element analysis was precise, which showed a potential application in practical engineering.

Abstract: Using NURBS modeling method can construct more realistic and vivid 3D models, because it has a remarkable ability to control the curves of the model surface than the traditional grid modeling method. Therefore, on analysis of the primary principles of NURBS, this paper adopted professional modeling software 3DS MAX to explore the methods and techniques of NURBS in the complex surface building process. And then, the techniques and methods were applied to construct practical engineering machinery, completing the 3D model of bulldozer case.

Abstract: In this paper, the design of Jujube Plantlet Uprising Machine adopts plantlet uprising shovel fixed to the frame on the right side, using the three-point hitch of the tractor to adjust plantlet uprising depth, through a deep round dig depth stability limit, to take over operation, improve the efficiency of the plantlet uprising. Equipment is designed to provide technical support for a large number of high quality standardized jujube nursery, to laid the foundation calculation for large-scale jujube cultivation.

Abstract: Granular flow is an important process in industry, agriculture and mining. This paper studies the flow pattern and optimization of two channels of granular chute flow merging into one channel. Experiment shows that the flow pattern in each channel can be dilute flow, shock or dense flow. Base on the discovery, one can optimize the flow rate in this system.

Abstract: Oil dampers are widely used as a popular countermeasure to mitigate the stay cables vibration. In this study, one actual oil damper designed for some long cable-stayed was experimentally investigated to evaluate the durability. 4 million cycles loading, with frequency of 4 Hz and amplitude of 1 mm, was imposed on the damper. The excitation displacement and damping force were measured and the equivalent damping was calculated from the experimental results. The stiffness effects of dampers behaved during durability tests were also analyzed quantitatively. The test results showed that the dampers were still in good condition after 4 million cycles loading and the dampers temperatures were stable at 50 degree centigrade during the test. According to the durability test results, a model for performance deterioration of damper was proposed to predict the lifetime of oil dampers.

Abstract: Fluctuation characteristics of the pressure drop distribution and liquid film distribution along a pipe of the oil-air annular flow in oil-air lubrication system are calculated respectively introducing Chisholm constant c base on the Chisholm theory and simulated by Fluent in this paper. The results show that the theoretical calculation results of the pressure drop and liquid film agree qualitatively with the simulation results, and the fluctuation characteristics of the pressure drop and liquid film thickness are augmented respectively when the air velocity increases. These conclusions will do favors for predicting and controlling the lubricant in the oil-air lubrication system.

Abstract: This paper introduces a new devices and technology of large-aperture quadratic optical components rapid powerful NC polishing, it has greatly improved the efficiency and precision of aspheric polishing. Through self-designed five-axis CNC polishing machine, to achieve the controlling of rotation, revolution integral rapid powerful polishing head. By optimizing the process parameters, determine a reasonable polishing path and polishing mode structure, to obtain good experimental results. Size 340mm × 340mm aspheric optical glass, surface shape accuracy PV λ / 5, surface roughness Rq 1.2nm, processing efficiency has been effectively improved, surface shape convergence stable.