Materials Science Forum Vols. 697-698

Abstract: The crank-slider mechanism is the key component in reciprocating pumps. With the increase of the rotational speed of the crank-slider mechanism, the vibration and working noise of reciprocating pumps increase. Based on the multi-body dynamics theory, the dynamic model of the crank-slider mechanism of reciprocating pumps is proposed. A numerical example is given and the validity of the procedure developed here is demonstrated by analyzing the dynamic behavior of a typical crank-slider mechanism of the reciprocating pump. The model can well simulate the dynamic response of the mechanism, which can enable designers to obtain required information on the analysis and design of reciprocating pumps.

Abstract: Mobile hard disk is very sensitive to vibration because of unique mechanical working and the complexity of components. In view of inner structure and complying with quality equivalent principle, a 2.5 inch mobile hard disk finite element model is established based on ANSYS/LS-DYNA. The crashworthiness evaluate index is analyzed and set forward. The influence of drop angle is analyzed through simulation. In theoretically, the results are proven to be fundamental method of crashworthiness analysis, evaluation and design for mobile hard disk.

Abstract: Ultra-precision flying cutting machining with a vertical milling style is an important means of ultra-precision machining. It has a close relationship between the machining accuracy and the dynamic characteristics of the aerostatic spindle. The film force acting on the spindle rotor is related to the manufacture, installation and static unbalance or dynamic imbalance or other factors. Therefore, it is necessary to analyze the dynamic pressure force caused by these factors in order to study on the rotor posture and quantitative movement of the spindle. This article derived the solution formula for the dynamic pressure reaction force of the ultra-precision machine tool spindle with vertical static film based on the basic theory of the rigid body dynamics. The gyroscopic torque of the spindle has been analyzed under different conditions with the spindle dynamic balancing tests, which provide a reference to the further analysis of the spindle dynamic characteristics.

Abstract: The objective of this paper was to study tool wear condition and to guide the cutter configuration by studying the movement of the disc cutter of all-section rock Tunneling Boring Machine(TBM).Through the analysis of rock destruction process by disc cutter based on spatial geometry theory and D-H matrix, the kinematic model of work cutter in rock destruction process was established and the movement law of cutting-tool is concluded, which are beneficial for the research on wear of disc cutter, structural design and optimization design of cutting tool configuration.

Abstract: According to the performance requirements of three-stage wind turbine gear box, the mathematical model was established as object function. Design of the gear box was optimized with genetic algorithm and the examples showed that design of the gear based on genetic algorithm can gain more optimized result. The method is a supplementary to reliability optimization methods for Wind turbine gear box.

Abstract: A lumped-parameter dynamic model for gear train set in wind turbine is proposed to investigate the dynamics of the speed-increasing gear box. The proposed model is developed in a universal Cartesian coordinate, which includes transversal and torsional deflections of each component, time-varying mesh stiffness, gear profile errors and external excitations. By solving the dynamic model, a modal analysis is performed. The results indicate that the modal properties of the multi-stage gear train in wind turbine are similar to those of a single-stage planetary gear set. A harmonic balance method (HBM) is used to obtain the dynamic responses of the gearing system. The responses give insight into the impact of excitations on the vibrations.

Abstract: There are two basic types of EPB shield cutter: panel type and spoke type. The efficiency and process of the driving work will be directly related to the chose of the cutter type. Torque model of the shield cutter can be established by analyzing the load under working conditions. Methods to analyze the efficiency of two different types of cutters under working conditions can be explored, through analysis with specific examples of projects in this paper. Thus, theoretical basis can be provided for analyzing and studying the efficiency of shield cutter.

Abstract: Commercial finite element modeling software ANSYS was used to calculate the stress and deformation distributions of crawler frame of the Rotary drill bits under turning work condition. By using finite element method, the weak points of the crawler frame can be found and the strength of the model can be calculated quickly and correctly. The results show that the crawler frame has enough strength to support the machine to finish the turning process and the maximum displacement distributed in the middle of the crawler frame. This paper will supply references for the structural optimize design of crawler frame of the rotary drill bits.

Abstract: The excavation stability takes an important role for EPB excavation in keeping surface stability and engineering safety. The prediction of EPB excavation stability based on geological data could improve the stability of the Shield. According to the data from geological prospect and field excavation, the mathematic model of the stability of Shield earth pressure balance has been analyzed, and the range of Shield thrust force has been ascertained. The nonlinear tendency of the resistance on cutting head has been confirmed by the analysis to the distribution of opening rate. The prediction standard of Shield excavation stability has been advanced in order to instruct the regulation of excavation chamber pressure and thrust force, and reduces engineering risk and cost.

Abstract: The stiffness analysis method considering uncertainty parameters of frame hydraulic press with movable eccentricity loading in the early design stage was proposed. The mathematical analytical stiffness of the upper beam with movable eccentricity loading was built. The adaptive Monte Carlo Method was used to calculate the interval of the stiffness with random parameters. The result shows that the stiffness appears higher when the eccentricity increasing. The approach has been tested by measuring the stiffness of a 10000kN frame hydraulic press and a 15000kN frame hydraulic press.