Applied Mechanics and Materials Vols. 633-634

Abstract: Kinematics model is established for offshore flexible riser fatigue testing machine using vector analytical method, and motion simulation was carried out by ADAMS software. The motion curves of driven member were got，correctness of design results were proved through comparing with theoretical value.

Abstract: For the problem of the design on the main components of backward rotary transplanting mechanism in wide-narrow row planting, finite element method based on SolidWorks Simulation was applied to analyze it. In the analysis, the defects in the design were discovered. By improving these defects, the aim of optimization design was achieved. This analysis and design method can effectively avoid the defects caused by conversion between different softwares, which has higher practical value.

Abstract: The tool’s unique movement trajectory in longitudinal and torsional ultrasonic machining technology can help chip extraction. Cutting liquid can offer good lubrication, cleaning and cooling. It also can prolong tool’s life, improve the processing quality and processing efficiency, so it is widely used in precision and ultra-precision machining. It builds the model of ultrasonic vibration system, based on the motion analysis of longitudinal and torsional ultrasonic vibration honing. In addition, mode analysis, transient dynamic analysis and harmonic response analysis are carried out by means of finite element analysis software ANSYS. Using graphics and curve in the postprocessing module describe the results of numerical simulation. It can provide powerful model and theoretical basis for the structure design and performance optimization of ultrasonic vibration system, which is used for longitudinal and torsional ultrasonic vibration honing.

Abstract: With the aim of probing the optimal cutterhead structure for sandy cobble stratum in Beijing metro, four typical cutterhead structure are presented. The load on the cutterhead is calculated. The finite element models of cutterhead with thickness of 350 mm, 400 mm and 500 mm for each structure style are established respectively. By analyzing the stress distribution for each model, we find that the maximum stress of spoke-style cuttehead are lower than that on the board-style cutterhead; the structural properties of cutterhead with straight corbel are better than that with oblique corbel. Finally, the optimal cutterhead structure and size for sandy cobble stratum is selected.

Abstract: The shape of thin film for flapping rotor wing has a significant impact on aerodynamics. To increase lift, we designed 7 different flexible film wings. Then we compared the aerodynamic force of thin film in accordance with the same aspect ratio of different shapes and the same shape of different aspect ratio. The conclusions suitable for the thin film design guide are obtained. The aspect ratio of thin film for flapping rotor wing is inversely proportional to the aerodynamic force. At the same aspect ratio, the film wing designed by bionic is superior to other shapes. With the aspect ratio increases, the thrust of the film wing designed by bionic decreases faster than the lift.

Abstract: The bearing lubrication system flow distribution design of the transmission was realized with a new system modeling method, targeted at the problem of a certain type of transmission’s bearings’ sintering. The heat-generated model and the flow-required model of the bearings and the gears were set up, and the required lubrication flow was obtained. The simulation model of the system flow distribution was established, the simulation analysis toward the dynamic characteristic of the transmission’s lubrication flow’s distribution was performed, and the results of the simulation analysis and the test were analyzed comparatively. The result showed that the simulation model matched the test result well, proving the effectiveness and correctness of the model of the transmission’s flow distribution.

Abstract: The distribution of the non-uniform in situ stress around wellbore will impair the stability of the rock of wellbore wall. Drilling the underbalanced wells and depleted formations, the instability of the wellbore can result in the drilling failure. Mechanics model of the wellbore wall rock is developed. According to the relationship between the stress function and components of stresses, the superposition principle is adopted to develop the formulas of the radial, hoop, and shear stresses of the wellbore wall under the non-uniform in situ stress. The formula of the mud density which do not crash the rock of wellbore wall is derived. The error of the mud density between fitting formula developed in the paper and theoretical method is less than 2.5%. The mud density that ensure the stability of wellbore is determined.