Table of Content

25 January 2008, Volume 19 Issue 2

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Research on Continously Automated Feed of Electrode Thread for Miniaturized EDM Device

Tang Yongjun Wang Zhenlong Guo Zhongning

2008, 19(2):  127-129. 

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In order to solve the problems of long lead-time,difficulty of holding and replacing electrode,the miniaturized EDM device with continuously automated feed of electrode thread had been designed.The technique is beneficial to increase the machining speed and depressing position deviation caused by reorientation of the electrode.Driving principle of ultrasonic motor was analyzed,and the vibration equations of ultrasonic motor were deducted.The tests of electrode driving effect and machining experiments have been fulfilled to validate the feasibility of feeding electrode mechanism.

Topology Optimization Design of Large-displacement Compliant Mechanisms Using Meshless Methods

Du Yixian Chen Liping Luo Zhen

2008, 19(2):  130-136. 

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Based on the continuum structural topology optimization, the element-free Galerkin method was applied to design large-displacement compliant mechanisms with geometrical nonlinearities.The multi-criteria mathematical formulation was developed using the SIMP（solidisotropic material with penalization）interpolation scheme and compromise programming,in which the mechanical flexibility and structural stiffness were both considered as the prescribed performances to be optimized. The optimization formulation was solved by optimality criteria method. The element-free Galerkin method was employed to discretize the design domain with the aim of avoiding the undesired mesh distortion caused by adopting finite element methods to deal with geometrical nonlinear problems.Numerical examples have been presented to demonstrate the effectiveness of the proposed approaches by analyzing the results derived from linear and nonlinear cases,respectively.

Simplified Fatigue Strength Calculation on the Root of Scroll Wrap Acted π-region Inner Pressure

Qiang Jianguo Ma Xiao Liu Zhenquan

2008, 19(2):  137-141. 

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The fatigue strength criterion for the root of scroll wrap was ascertained,the simplified formula of Von mises stress of root of scroll wrap acted π-region inner pressure were obtained by fiting the simulated results using finite element method.Considering stress concentration on root of scroll wrap,the safety factor and the minimum calculation safety factor were calculated and the fatigue strength on root of scroll wrap was analysed.All of the calculated examples prove that the calculated results are well agree with the simulated results using finite element method.The study shows that reasonable combination of basic parameter and material is essential to improve the fatigue strength of root scroll wrap and the equivalent loops of the scroll wrap also will be not too much.

Soft-Sensing Modal of the AC Asynchronous Electrical Dynamometer Based on SVR

Zhang Guixiang Chen Hongwei

2008, 19(2):  142-145. 

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In order to solve the problem of very expensive and complicated measurement system currently used,this paper first analysed the factors which affect the speed and torque of the AC asynchronous electrical dynamometer,then put forward a soft-sensing modal based on the support vector regression,which can be used to approximate nonlinear function in the whole region.The experiments prove that the proposed model is effective,and it affords a new method for the measurement of the input power,output power and the torque in the power-mechanical field.

Comparison Study on Mechanical Filtering Characteristics between Periodic Mount and Uniform Mount

Zheng Ling Li Yinong Amr Baz

2008, 19(2):  146-149. 

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The theory governing the operation of this class of passive periodic mounts was introduced by using spectral finite element and transfer matrix methods.The filtering characteristics of periodic mounts made of aluminum and rubber was compared with that of uniform mounts made of aluminum.Experiments were performed to verify the numerical prediction. The results show that the stop band can be tuned by modifying material and geometric parameters of periodic mounts.This also demonstrates the potential of these periodic mounts to stop or confine the propagation of undesirable disturbance from vehicle engine.

Study on T-S Fuzzy Control for Pneumatic Position Servo System

Bai Yanhong Li Xiaoning

2008, 19(2):  150-154. 

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In order to make the pneumatic position servo system adaptable to the variations of the operating positions and payloads, fuzzy control based on Takagi-Sugeno model(shorted as T-S model) was proposed to be used.Taking the pneumatic rotary actuator position servo system with proportional valve as an example,the key techniques to design T-S fuzzy controller for pneumatic position servo
system was studied,including the choice of the premise variables,the division of the subsystems,the definition of the membership functions of premise variables,the design of the local controllers and so on.With the developed T-S fuzzy controller, a lot of experiments had been carried out. Experimental results show that the system has better control performance for any positions within the stroke of the actuator and any payloads in a certain range.

Research on the Equivalent Electromechanical Dynamics Model and the Characteristics of Piezoelectric Smart Active Member

Wang Guangqing

2008, 19(2):  154-159. 

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Experimental Research on the Noise Performance of a Water Hydraulic Piston Pump

He Xiaofeng Zeng Wei Wang Xuebing Liu Meixia Zhu Yuquan

2008, 19(2):  160-162. 

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Based on the structure and principle of an axial water hydraulic piston pump with check valves, the main reasons causing noise about the pump were analyzed. Then contrast experiments on the noise performance of the water hydraulic pump under different structural types of check valves, the pump’s main shaft in dynamic balance and unbalance, under different rotating speed and displacement, had been accomplished. The testing results show that the noise value of the water hydraulic pump can be obviously reduced when its main shaft is in dynamic balance comparing with unbalance status, the pump’s noise adapting flate type check valves is lower than mushroom type, the noise can also be depressed by using a pump with large displacement and lower rotating speed. Besides, the physical dimensions of the check valves affect the pump’s noise markedly

Singularity Analysis of the Stewart Platform Based on Improved Ant Colony Algorithm

Yang Peng Liang Lihua Li Guobin

2008, 19(2):  163-166. 

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Aiming at the singularity analysis of the Stewart platform, the determinant of the Jacobian matrix was selected as the objective function, and the continuous optimization problem was proposed in the work space of parallel machine. By improving global searching, local searching and pheromone update rule, the novel ant colony algorithm had been presented for solving the continuous optimization problem. Then this method was applied to the singularity analysis of the Stewart platform. The results show that the improved algorithm has good ability of global optimization and fast convergence. This novel ant colony algorithm provides valuable reference for the problem like the singularity analysis of the parallel machine.

Chip Morphology and Cutting Forces in High Speed End Milling of Hardened P20 Steel

Pang Junzhong Wang Minjie Qian Min ZhangJun

2008, 19(2):  170-173. 

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Using 12mm diameter solid carbide straight end mills with TiAlN coating, a P20 steel at 41HRC was machined in the milling speed range of 151 to 942 m/min. The morphology of the chips and the milling forces at various speeds were investigated. Chips are found to be continuous at 151 to 650 m/min. The saw-tooth chips are formed at 754 to 942 m/min. The forces increase with the increasing of milling speeds. They increase to maximum when the milling speed approaches to the critical value. After the speed, the increases of the milling speeds cause decreases of the cutting forces. Furthermore, based on chip formation theory at high speed machining, the effect of milling speed on milling forces were investigated.

Research on Costing Estimation of ASP-services Oriented Service Customization

Liu Qiang Chen Xindu Chen Xin

2008, 19(2):  188-193. 

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By analyzing the characteristics of running and costing-forming process of ASP system, a detail table of costing construction was designed based on the software engineer. ASP service just was regarded as an abstract product of ASP system, so the activity-based costing(ABC) method was imported to estimate the costing and efforts of ASP service. At first, those activity center was defined based on the construction of costing of ASP system. Then, a series of cost driving factors were acquired by deeply and detail analysis. furthermore, a ABC-based Costing Estimate Model(ABCCEM) for ASP service was devised. At last, a instance was demonstrated to illuminate the application way of ABC-CEM. 

Algorithm for Arbitrary Complex Surface Flattening and Its Application in Unfolding Metal Blank

Xu Jiangping Liu Yuqi Du Ting Zhang Zhibing

2008, 19(2):  193-195. 

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A new algorithm for transforming any complex surface into a plane presented herein was applied in finite element inverse approach with initial guess, then the advantageous initial displacement was obtained. This algorithm is characterized by its fast calculation, precision, easy implementation and perfect practice. This paper introduced essential steps of this algorithm in detail, and validated the correctness and precision of this algorithm by large number of double curved surfaces. It is applied in the field of sheet metal forming, and widely applied in the field of aircraft, automobile, costume design, toy-making, shoe-making etc. 

Numerical Study and Working Behavior of Hypospray

Chen Bo Wang Hongdan Wu Jiankang Shi Tielin

2008, 19(2):  196-199. 

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This paper employed CFD Fluent software to numerically investigate working process of a hypospray. Attenuation behaviors of medication driving pressure and medical jet speed were obtained. Evolution of medical jet in air and penetrating process through surface skin were simulated. Numerical solutions are comparable with experimental results.

Kinematics Analysis and Fully-Isotropic Design of a Novel Parallel Robotic Manipulator

Zhang Yanbin Wu Xin Liu Hongzhao Zhang Minghong

2008, 19(2):  213-216. 

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A novel spatial parallel robotic manipulator with 3-dof, containing two-translational and one-rotational, was proposed. Solutions of position and velocity for both direct and inverse kinematics were analyzed. The singularities were discussed in detail. Jacobean matrix of the manipulator is a diagonal 3×3 matrix, thus it is uncoupled. Isotropic design was performed according to the requirement that the conditioning number of Jacobean matrix was always equal to 1. The condition of structural size, which satisfies the manipulator to be a fully-isotropic one, is obtained.

Multi-Objective Direct Optimization Method for CAD Model Based on Uniform Design and NN-GA

Sui Tianzhong Lin Wenqiang Zheng Xiaoxin Wen Bangchun

2008, 19(2):  222-225. 

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A multi-objective direct optimization method based on uniform design and NN-GA was proposed. This method dealed with test project using uniform design principle, utilizing drive characteristics about 3D CAD model, accomplished virtual testing course and data collecting. On the basis of this, taking these data as training sample, a neural network model of nonlinear mapping relations between parameter and object of CAD model was established. Applying Pareto genetic algorithm and niche technique, Multi-Objective Parameters Optimization of CAD model was done. A Pareto optimal set of CAD model can be found in specific extent.

Research on Strip Shape Control Technology on Continuous Galvanizing Line

Chang Tiezhu Zhang Qingdong Jiang Zhenglian Wu Bin

2008, 19(2):  231-235. 

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By using the technique of Varying Contact-Length backup roll on SPM and corresponding simulation in finite element method, neural network on-line setting for processing parameters of tension leveller, analytic calculation of the stress field in the coil during the process of reeling with the iteration of layer by layer, optimization of processing parameters for reeling, and also by experimental investigation on site, a set of shape control techniques and technical counter measures were advanced. Applying these measures to CGL, good effect of shape control are obtained, and the quality of profile shape and the up-to-standard rate are also upgraded markedly. 

A Novel 3-DOF Translational Parallel Mechanism and Its Position Analysis

Zeng Daxing Huang Zhen Hou Yulei

2008, 19(2):  239-241. 

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A novel 3-DOF parallel mechanism that can perform three-dimensional translations was investigated herein. At first, the degree-of-freedom and possible motion were defined by using screw theory. Then closed-form inverse displacement solutions were obtained based on the characteristics of the parallel mechanism and the forward displacement problem was analyzed by using the Bezout’s elimination method. At last, a numerical example was given in order to prove the correctness of the inverse and forward displacement solutions.

Gate Location Design of Injection Molding Based on Feature Warpage Optimization

Li Jiquan Li Dequn Guo Ziying

2008, 19(2):  242-245. 

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Taking into account the great influences of gate location on part warpage, the computer aided engineering for injection molding was combined with optimization technology to find the optimal gate location with minimized feature warpage. A simulated annealing algorithm was used to search the optimum. Finally, an example was given to demonstrate the effect of proposed method.

Analysis and Evaluation for Usability-Stability of the Stainless Steel Covered Electrode

Wang Yong Wang Bao

2008, 19(2):  245-248. 

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Tendency of the flux-wall guided transfer is the main symbol to judge usability-stability of the stainless steel covered electrode. Using the Analysator Hannover, welding electric parameters of the stainless steel covered electrode were measured and analyzed. Four characteristic information values correlated with tendency of the flux-wall guided transfer were extracted, such as the sum of probability density of short-circuiting voltage, mean value of arc voltage, mean value of welding current and frequency of short circuit, and then method of principal component analysis was applied to determine the evaluation index of usability-stability of the stainless steel covered electrode. It offers a new method for quantitatively judging metal transfer modes and scientifically evaluating usability-stability of the stainless steel covered electrode.