Papers by Author: Zhi Yuan Rui

Abstract: In order to control effectively the temperature of the motorized spindle, based on thermodynamics, heat transfer theory and fluid dynamics control theory, the model of motorized spindle with cooling system is established and simulated. Based on the idea of orthogonal experiment and simulation experiment, the comprehensive tests are built, and the optimum matching relation between the heat flux of motor and the flow velocity of cooling liquid is determined in this article. The results show that the flow velocity of coolant can be adjusted according to the heat flux of motor which can control the temperature in the steady range and improves the cooling effect.

Abstract: The gating system of an injection mold for car bumper was studied. A design optimization scheme is proposed to optimize both the number and locations of the gates by analyzing the filling process, in order to reduce the part war page and weld line, numerical simulation of injection mold filling process is combined with the design optimization method to find the optimum number of gates and their locations to achieve balanced f low and less weld lines while satisfying the limit of injection pressure. Moldflow software was applied to make analysis and comparison of various gating system in terms of their filling time, injection pressure and clamp force, weld line and distribution of air traps, and an optimized gating system was obtained. The result shows that this method can effectively reduce costs, shorten development cycle and improve the efficiency of molding design.

Abstract: This paper focus on the spindle system of special friction welder machine with conductive device made up of aluminum electrolytic prebaked anode. The ROMAX software is employed to analyze the spindle system, and the spindle axial force and displacement, radial displacement, and natural frequency are obtained by the analysis. The reasonable result can be got by analyzing the corresponding results, respectively. Thereby, the gist to improve the fiction welder is attained.

Abstract: Study of grain size and lamellar spacing on fatigue crack propagation resistance in TiAl alloy has been done. The effects have been analyzed specifically. Meanwhile, the influence has been verified with some fatigue crack propagation experimental results and Paris formula. The experimental results confirmed that the grain size and lamellar spacing have significant effect on fatigue crack growth resistance. According to the Paris formula, the specific values of the constants in the formula were calculated.

Abstract: For the shorting of fracture mechanism from the point of high temperature condition, so a new method of illustration, which is carried out under the condition of high temperature, for fracture mechanism will be adopted in this paper. And a more accuracy and more understandability result can be got by this new method. Besides, the performance of TiAl alloys can be improved by making grains refined to decrease the slip plane spacing, which can be got from the mechanics analysis.

Abstract: Based on the experiments did by B.K.Parida and T.Nicholas [1], the fatigue crack propagation rate of TiAl alloy under different stress ratios had been tested in order to find out the role of stress ratio and to derive an improved fatigue crack propagation formula for region II(the expansion region) according to Paris formula and to calculate the specific values of the constants in the formula. The experimental results reveal that stress ratio has a significant influence on fatigue crack growth rate.

Abstract: With the Synchronous Dual Ball Screw Feeding System used in a Milling-Turning compound machining center as the research object. For study the ball screw vibration modal, which using Lagrange established the dynamics equation and using the Lizs series expansion analyzing its various order modal coupling characteristics. Meanwhile using the ANSYS analysis to get the first three order vibration mode diagram and calculate the frequency corresponding to the critical speed for each rank. Through the analysis found that the screw pitch determine the modal coupling axial and corner, the workbench position and load quality changes, the screw vibration frequency also changes. Provide theoretical analysis for the analysis of dynamic characteristics of the next step.

Abstract: Electrolytic aluminium pre-baked anode conductive device for the special friction Welder upsetting system is the research object. Establish dynamic equation of the upsetting system by its Lagrange equation; analyze the key factors affecting the systems dynamic characteristics; build the systems finite element model to be real by ANSYS Workbench; Set key parameters for the two sets of plans and do analysis for the modal and harmonic response successively. The two plans compared results reveals that the guide spacing and the damping among all the parts can affect the systems dynamic characteristics, which will provide a basis for further improvement and optimization of special friction welding machine bed.

Abstract: The model that describes the friction between contact surfaces of motion pair of the feed system has been established use of Stribeck friction theory, it fully reflected the various lubrication conditions. The bifurcation and stability analysis of the model has been done. The experimental methods were used to research the nonlinear dynamics characteristics of the feed system under the external excitation. The influences that friction force to the nonlinear characteristics of the system at the certain parameters condition were analyzed. Utilize the research findings of the dynamical characteristics that caused by friction in the feed system can effectively provide a theoretical basis for designing optimization of complex systems in engineering, fault diagnosis and vibration control.

Abstract: The theory of structural dynamic analysis is put forward firstly. Then the dynamic performance of HMC80 high-speed precision machining center column is analyzed by means of finite element method. The dynamic performance of the column is analyzed using structural dynamic optimization theory and variation analysis with the thickness of wall plate and the inner rib plates as the parameters thirdly. Based on the analysis results, the structure optimization scheme of the column is obtained. The structure optimization scheme is analyzed and the analysis results show that the dynamic performance of the column optimization scheme is improved obviously.