Advanced Materials Research Vols. 753-755

Abstract: This paper focuses on the transform relationships between each element and between elements with inertial system under different attitude coordinate system in the finite element multi-body system mechanical analysis of the flexible rope process. It mainly research the attitude coordinate transformation matrix between the of flexible rope Micro-element and inertial system under the four coordinate system which are the direction cosine coordinates, finite rotation four element coordinates, Euler angle coordinate and Cardan angle coordinates, and the relationship between the connecting base on the element type and inertial reference based.

Abstract: In order to improve the stability of feed movement in high speed CNC system, the feedrate planning algorithm based on piece-wise polynomial function was proposed. The flexible transition of feedrate was realized through maintaining linear continuous jerk. The principle of the proposed algorithm was introduced and the method to generate smooth motion profile based on the proposed algorithm was presented. The proposed algorithm is simple and it can be applied in acceleration/deceleration before interpolation in high speed feed movement to improve the stability of it. The proposed algorithm was applied in multi-contour high speed processing and the result indicated that it could improve the stability of large-scale parts motion.

Abstract: In order to suppress the lateral vibration of high-speed train caused by track irregularity, the delayed feedback control is employed to suppress the vibration of the semi-active suspension system. The 1/4 vehicle mathematical model of semi-active suspension system is established. The amplitude of the bodys lateral vibration is large at some values of external excitation frequency for the passive suspension system, and it could be suppressed at some values of time delay, while the vibration of the bodys lateral vibration may be deteriorated at other values of time delay. The results show that the amplitude of the bodys lateral vibration could be suppressed about 50% when the suitable values of damping coefficient and time delay are chosen by comparing with the passive suspension system. The analytical results of this paper are in good agreement with the numerical simulation.

Abstract: In order to solve the problems existed in gearshift with wet dual clutch transmission; the down-shift control strategy is developed on the basis of analysis on gear shift process. Clutch pressure intelligent control arithmetic based on FCMAC (Fuzzy Cerebellar Model Articulation Controller) is designed to realize accuracy control of clutch pressure. The transmission control unit is designed, and the control program is written. Taking down-shift from 2 to 1 for example, down-shifting control strategy was drawn. After applied the introduced method into the experiments on both power-on and power-off downshift under different throttle positions, ideal shifting quality was achieved. The result indicated that the speed of vehicle changed gently without distinct impact. This essay verifies the validity of the proposed method of the strategy of shifting control.

Abstract: In order to research the principle of crankshaft horizontal-bending vibration, free modal experiments of 4105 diesel engine crankshaft vibration was designed and done. Vibration parameters of free vibration, torsional vibration, vertical-bending vibration and horizontal-bending vibration were obtained respectively through different measurements points setting and motivation techniques. Through analysis of frequencies and models, a conclusion was drawn:the torsional vibration was just coupling with the horizontal-bending vibration.

Abstract: In order to understand Isolated Heat Transfer Gaskets placement scheme's influence on the dynamic performance of the MED electric control box,on the basis of theoretical analysis, Finite Element Modal analysis and random vibration analysis have proceeded for different Isolated Heat Transfer Gaskets placement program, and comparative analysis of the two results. Analysis results provide the basis for further optimal design of the MED electric control box.

Abstract: The dynamic vibration absorber (DVA) is generally used to suppress the machining vibration in boring processes. The DVA consists of an additional massspringdamper sub-system, and needs accurately tuning of its natural frequency and damping ratio to match the main structure for vibration control. For obtaining the optimal performance of the DVA, the parameters of the DVA used in a boring bar is identified using modal correlation method, which combines the finite element analysis method with test modal method to validate the FEMs results. The analysis results show that the modal correlation method is an effective and simple method to accurately identify the dynamic parameters of DVA and guarantee the optimal design of the DVA for boring chatter control.

Abstract: To solve the instability of the single pair bars RCCR mechanism, the analysis of kinetic characteristics and force rules of three pairs of dowel bars Equal-offset space RCCR mechanism was done. And then the simulation of the theoretical results was verified by SolidWorks simulation software. Finally ,the important conclusions are obtained.

Abstract: Fully-welded ball valve has been applied in large oil and gas pipelines, and its quality is directly related to the safety of the transportation of national energy. The wall thickness of 48900lb ball valve is greater than theoretical design thickness. In this article, FEM software was used to design minimum wall thickness using linear stress analysis method. Though changing wall thickness under design pressure, the minimum wall was 95mm which calculated by linear stress analysis method can provide theoretical support for practical engineering application.

Abstract: A novel method based on damage line is put forward to improve the prediction accuracy of fatigue life under variable amplitude loads. According to fatigue strength change before and after the damage line, mechanical parts service processes are divided into undamaging and damaging process. Undamaging process life, damaging process life and fatigue life are calculated by the novel method. The prediction results are closer to the actual situation. In order to simplify calculation, the damaging process is regarded as linear process. The results are more accurate than traditional fatigue life prediction method. The novel method can be widely used in light-weight constructions, reduction of time-to-market period, product safety, reliability design and so on.