2003 Vol.16(3)

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FULL-FRONTAL COLLISION SIMULATIONS AND ANALYSES OF TUBULAR SPACE FRAME BODYWORK FOR SEDAN CAR
2003, 17(3).
[Abstract](2454) [PDF 182KB](156)
Abstract:
Using CAE tools based on nonlinear finite element methods, full-frontal collision dynamic simulation and analysis of a sedan car body with 3D tubular loadbearing frame are tenta-tively carried out. Time histories of the main collisional parameters are pre-sented, improvements of the frame are partially made according to simulation results. Collisional simulation of the tubular frame alone indicates that, such new type of bodywork for sedan car is of good potentialities to meet the collision safety regulations.
MAGNETIC FIELD ANALYSIS OF ELECTROMAGNETIC VALVE TAKING HYSTERESIS INTO ACCOUNT
2003, 17(3).
[Abstract](2258) [PDF 92KB](143)
Abstract:
Predicting and optimizing of the high-speed solenoid on/off valve behavior requires an accurate model of the hysteresis loop of the magnetic material used. A ferromagnetic hystere-sis model and a novel algorithm based on fixed–point technique to optimize the electromagnetic model are introduced. By utilizing a modified vector Preisach model of magnetic hysteresis and the global genetic optimization algorithm based on partial mapping cross method, the B-H relation loops are identified accurately.
METHOD TO EXTRACT BLEND SURFACE FEATURE IN REVERSE ENGINEERING
2003, 17(3).
[Abstract](2317) [PDF 187KB](120)
Abstract:
A new method of extraction of blend surface feature is presented. It contains two steps: segmentation and recovery of parametric representation of the blend. The segmentation separates the points in the blend region from the rest of the input point cloud with the processes of sampling point data, estimation of local surface curvature properties and comparison of maximum curvature values. The recovery of parametric representation generates a set of profile curves by marching throughout the blend and fitting cylinders. Compared with the existing approaches of blend surface feature extraction, the proposed method reduces the requirement of user interaction and is capable of extracting blend surface with either constant radius or variable radius. Application examples are presented to verify the proposed method.
APPROACH ON INTELLIGENT OPTIMIZATION DESIGN BASED ON COMPOUND KNOWLEDGE
2003, 17(3).
[Abstract](2328) [PDF 78KB](49)
Abstract:
A concept of an intelligent optimal design approach is proposed, which is organized by a kind of compound knowledge model. The compound knowledge consists of modularized quantitative knowledge, inclusive experience knowledge and case-based sample knowledge. By using this com-pound knowledge model, the abundant quantity information of mathematical programming and the symbolic knowledge of artificial intelligence can be united together in this model. The intelligent optimal design model based on such a compound knowledge and the automatically generated decomposition principles based on it are also presented. Practically, it is applied to the production planning, process schedule and optimization of production process of a refining & chemical work and a great profit is achieved. Specially, the methods and principles are adaptable not only to continuous process industry, but also to discrete manufacturing one.
STUDY ON ELEVATED TEMPERATURE MECHANICAL PROPERTIES OF AM50HP WITH ND
2003, 17(3).
[Abstract](2197) [PDF 378KB](179)
Abstract:
Effects of Nd on the mechanical properties of die casting magnesium alloys AM50 are investigated. It is found that the ultimate tensile strength, yield strength and elongation of the AM50 alloy at elevated temperatures up to 200 °C increase with an addition of Nd. Generally, the most significant improvement in the tensile properties is attained at 100 °C. The presence of Mg12Nd is proved by X-ray diffraction. Microstructural observations reveal that the addition of Nd can lead to the dispersion-strengthening. Due to the presence of Mg12Nd, the sliding of grain boundaries is restrained and the strength of the alloy is enhanced. It can be seen from the tensile fractographs that the fracture surfaces exhibit the mixed fracture characteristics, and less brittle fracture is observed with increasing the temperature. Quasi-cleavage fracture is thought as the main fracture mode. TEM observations expose the formation of dislocation network, slip lines and dislocation pile-ups.
DYNAMIC MATHEMATICAL MODELING AND APPLICATION FOR PUMPING SYSTEM PERFORMANCE INTEGRATED EVALUATION
2003, 17(3).
[Abstract](2066) [PDF 138KB](52)
Abstract:
A mathematical model is set to evaluate the overall centrifugal pumping system using asynchronous motor as power. This method can be used to affirm system performance according the transform and the aberrance of interior parameters and exterior performance curves so as to give a reference to the equipment amelioration. The analysis of emulation experiment data suggests the model is effectively used.
INTEGRATED LAYOUT DESIGN OF CELLS AND FLOW PATHS
2003, 17(3).
[Abstract](2133) [PDF 81KB](93)
Abstract:
The integrated layout problem in manufacturing systems is investigated. An integrated model for concurrent layout design of cells and flow paths is formulated. A hybrid approach combined an enhanced branch-and-bound algorithm with a simulated annealing scheme is proposed to solve this problem. The integrated layout method is applied to re-layout the gear pump shop of a medium-size manufacturer of hydraulic pieces. Results show that the proposed layout method can concurrently provide good solutions of the cell layouts and the flow path layouts.
OPTIMIZATION DESIGN OF HYDRAULIC MANIFOLD BLOCKS BASED ON HUMAN-COMPUTER COOPERATIVE GENETIC ALGORITHM
2003, 17(3).
[Abstract](2098) [PDF 75KB](79)
Abstract:
Optimization design of hydraulic manifold blocks (HMB) is studied as a complex solid spatial layout problem. Based on comprehensive research into structure features and design rules of HMB, an optimal mathematical model for this problem is presented. Using human-computer cooperative genetic algorithm (GA) and its hybrid optimization strategies, integrated layout and connection design schemes of HMB can be automatically optimized. An example is given to testify it.
DESIGN OF COMBINED CYCLE GENERATION SYSTEM WITH HIGH TEMPERATURE FUEL CELL AND STEAM TURBINE
2003, 17(3).
[Abstract](2071) [PDF 51KB](94)
Abstract:
For environment protection and high efficiency, development of new concept power plant has been required in China. The fuel cell is expected to be used in a power plant as a centralized power station or distributed power plant. It is a chemical power generation device that converts the energy of a chemical reaction directly into electrical energy and not limited by Carnot cycle efficiency. The molten carbonate fuel cell (MCFC) power plant has several attractive features I.e. high efficiency and lower emission of Nox and Sox. A combined cycle generation system with MCFC and steam turbine is designed. Its net electrical efficiency LHV is about 55%.
FUZZY NEURAL NETWORK FOR MACHINE PARTS RECOGNITION SYSTEM
2003, 17(3).
[Abstract](2114) [PDF 64KB](74)
Abstract:
The primary purpose is to develop a robust adaptive machine parts recognition system. A fuzzy neural network classifier is proposed for ma-chine parts classifier. It is an efficient modeling method. Through learning, it can approach a random nonlinear function. A fuzzy neural network classifier is presented based on fuzzy mapping model. It is used for machine parts classification. The experimental system of machine parts classification is introduced. A robust least square back-propagation (RLSBP) training algorithm which combines robust least square (RLS) with back-propagation (BP) algorithm is put forward. Simulation and experimental results show that the learning property of RLSBP is superior to BP.
ROBUST STABILITY ANALYSIS FOR RAILWAY VEHICLE SYSTEMS
2003, 17(3).
[Abstract](2085) [PDF 88KB](60)
Abstract:
The lateral stability for railway vehicle dynamic system with uncertain parameters and nonlinear uncertain force vector is studied by using the Lyapunov stability theory. A robust stability condition for the considered system is derived, and the obtained stability bounds are not necessarily symmetric with respect to the origin in the parameter space. The lateral stability analysis for a railway bogie model is analyzed by using the proposed approach. The symmetric and asymmetric results are both given and the influence of the adjustable parameter b on the stability bounds is also discussed. With the help of the proposed method, the robust stability analysis can provide a reference for the design of the railway vehicle systems.
APPLICATION OF ARCHITECTURE BASED NEURAL NETWORKS IN MODELING AND PARAMETER OPTIMIZATION OF HYDRAULIC BUMPER
2003, 17(3).
[Abstract](2110) [PDF 89KB](49)
Abstract:
The dynamic working process of 52SFZ-140-207B type of hydraulic bumper is analyzed. The modeling method using architecture-based neural networks is introduced. Using this mod-eling method, the dynamic model of the hydraulic bumper is established; Based on this model the structural parameters of the hydraulic bumper are optimized with Genetic algorithm. The result shows that the performance of the dynamic model is close to that of the hydraulic bumper, and the dynamic performance of the hydraulic bumper is improved through parameter optimiza-tion.
CONTROL SCHEMES FOR CMAC NEURAL NETWORK-BASED VISUAL SERVOING
2003, 17(3).
[Abstract](2124) [PDF 171KB](363)
Abstract:
In IBVS (image based visual servoing), the error signal in image space should be transformed into the control signal in the input space quickly. To avoid the iterative adjustment and complicated inverse solution of image Jacobian, CMAC (cerebellar model articulation controller) neural network is inserted into visual servo control loop to implement the nonlinear mapping. Two control schemes are used. Simulation results on two schemes are provided, which show a better tracking precision and stability can be achieved using scheme 2.
PARTICLE DISTRIBUTION IN CENTRIFUGAL ACCELERATING FIELDS
2003, 17(3).
[Abstract](2125) [PDF 188KB](55)
Abstract:
Based on continuum theory and moving law of particles, a model is presented to obtain gradient distribution of particles in centrifugal accelerating field, by which the particle distribution in gradient composite material can be predicted. The simulation shows with increases in rotating time, four regions gradually appear from the internal pe-riphery to the external one, they are free region, transition region, steady region and surface reinforced region,and the latest three regions are defined as a rich region. Finally, the steady region disappears, and the rich region only includes transition region and surface reinforced region. The influences of centrifugal acceleration coefficient G,primary volume fraction j0,pouring temperature qp and density difference between the particle and the metal matrix on particles gradient distribution are studied in detail. The results of the theoretical analysis agree with experiment ones. Both of analysis and experiment results indicate that with the increase in G and qp, the particle distribution becomes more centralized and the consistence of particle in the surface periphery becomes larger.
EFFICIENCY ANALYSIS OF DOUBLE CRANK RING--PLATE-TYPE PIN-CYCLOIDAL GEAR PLANETARY DRIVE
2003, 17(3).
[Abstract](2116) [PDF 139KB](604)
Abstract:
From the general formula for calculating the efficiency of planetary gear trains, the efficiency of the double crank ring-plate-type pin-cycloidal gear planetary drive is derived. To prove the theory, an experimental study has been conducted. The tested value of the effi-ciency of a sample set of the new-type drive in the experiment agrees with the calculated one. It shows that the new-type drive is of not merely high bearing capacity, but also quite high efficiency.
STOCHASTIC OB-JECTORIENTED PETRI NETS (SOPNS) AND ITS APPLICATION IN MODELING OF MANUFACTURING SYSTEM RELIABILITY
2003, 17(3).
[Abstract](2112) [PDF 144KB](131)
Abstract:
Object-oriented Petri nets (OPNs) is extended into stochastic object-oriented Petri nets (SOPNs) by associating the OPN of an object with stochastic transitions and introducing stochastic places. The stochastic transition of the SOPNs of a production resources can be used to model its reliability, while the SOPN of a production resource can describe its performance with reliability considered. The SOPN model of a case production system is built to illustrate the relationship between the system's performances and the failures of individual production resources.
PREDICTION OF ACOUSTIC PERFORMANCE IN EXPANSION CHAMBER MUFFLERS WITH MEAN FLOW BY FINITE ELEMENT METHOD
2003, 17(3).
[Abstract](2132) [PDF 129KB](357)
Abstract:
The equation of wave propagation in a circular chamber with mean flow is obtained. Computational solution based on finite element method is employed to determine the transmission loss of expansive chamber. The effect of the mean flow and geometry (length of expansion chamber and expansion ratio)on acoustic attenuation performance is discussed, the predicted values of transmission loss of expansion chamber without and with mean flow are compared with those reported in the literature and they agree well. The accuracy of the prediction of transmission loss implies that finite element approximations are applicable to a lot of practical applications.
DATA TRANSFORMATION OF FAULT TREE BY USING MATRIX OPERATION
2003, 17(3).
[Abstract](2094) [PDF 72KB](92)
Abstract:
On the base of study of the correlation of fault tree's main data-minimum cut sets, minimum path sets, non-intersect minimum cut sets and non-intersect minimum path sets, transformation method among main data are found, I.e. the transformation can be realized by the operation of cut sets matrixes. This method provides a new way to reduce “NP” difficulty and simplify FTA.
RESEARCH ON THE CONSTRAINT MAPPING FROM FUNCTION TO ASSEMBLY
2003, 17(3).
[Abstract](2125) [PDF 84KB](93)
Abstract:
Assembly sketch is not only the visualization of abstract function, but also the template of detail design. Two kinds of information are needed to create assembly sketch: structure and assembly constraint. Most researches are aimed at how to obtain structures from function, but the problem of how to obtain assembly constraint from function is ignored. Following the definition of assembly unit and the classification of function, a hierarchical mapping method from function to assembly constraint is put forward, and the mapping method includes two steps. The first step is the mapping from function to assembly semantics which is assembly expression and accordant with engineer's design habit. The second one is the mapping from assembly semantics to basic assembly constraints that are convenient for computer to handle. The mapping method is applied to DDMS (design, drafting and management system) successfully.
SURFACE MESH PARAMETERIZATION WITH NATURAL BOUNDARY
2003, 17(3).
[Abstract](2124) [PDF 223KB](68)
Abstract:
Using the projected curve of surface mesh boundary as parameter domain border, linear mapping param-eterization with natural boundary is realized. A fast algorithm for least squares fitting plane of vertices in the mesh boundary is proposed. After the mesh boundary is projected onto the fitting plane, low-pass filtering is adopted to eliminate crossovers, sharp corners and cavities in the projected curve and convert it into an eligible convex parameter domain boundary. In order to facilitate quantitative evaluations of parameterization schemes, three distortion-measuring formulae are presented.
STUDY ON THE COAL-ROCK INTERFACE RECOGNITION METHOD BASED ON MULTI-SENSOR DATA FUSION TECHNIQUE
2003, 17(3).
[Abstract](2107) [PDF 73KB](398)
Abstract:
The coal-rock interface recognition method based on multi-sensor data fusion technique is put forward because of the localization of single type sensor recognition method. The measuring theory based on multi-sensor data fusion technique is analyzed, and hereby the test platform of recognition system is manufactured. The advantage of data fusion with the fuzzy neural network (FNN) technique has been probed. The two-level FNN is constructed and data fusion is carried out. The experiments show that in various conditions the method can always acquire a much higher recognition rate than normal ones.
STUDY OF REGULARITY OF GENERAL-LINEAR-COMPLEX SINGULARITY OF 3/6-STEWART MECHANISM
2003, 17(3).
[Abstract](2148) [PDF 104KB](55)
Abstract:
The general-linear-complex singularity of Stewart mechanism is a very important problem in the parallel manipulator. Its general regularity is not found yet during the past two decades. St-Onge and Gosselin pointed out that the singularity locus of the Stewart mechanism at some given orientations of the moving platform should be polynomial expressions with varied degrees in 2000, but they didn't formulate the expression. Based on the kinematics singularity principle and the geometry condition proposed by Huang Zhen in 1999, firstly the singularity equation in degree two is derived. It is a hyperbola when the orientation of the moving platform is given. This result is also proved using screw theory. Then some singularity surfaces are gotten in three-dimensional space. This result is of important significance.
RESEARCH ON THE PERFORMANCE OF NEW TYPE OF PROPORTIONAL PRESSURE AND FLOW CONTROL VALVE
2003, 17(3).
[Abstract](2146) [PDF 142KB](88)
Abstract:
A new closed loop flow controlling principle through correcting the valve's opening area while load pressure is changing is carried out. Further more a principle using only one proportional valve to compound control pressure and flow is suggested. By using very simple proportional throttle valve in structure, the functions that five kinds of proportional valves or any two of them combined possess can be complimented. After analyzing, comparing, and testing the dynamic and static characteristics of valve with different controlling principles and main valve structure styles, the optimized structure styles and control methods are achieved.
PRODUCT DATA PREDICTION WITH UNCERTAINTY IN PRODUCT LIFE CYCLE DESIGN
2003, 17(3).
[Abstract](2135) [PDF 87KB](68)
Abstract:
Various kinds of data are used in new product design and more accurate data make the design results more reliable. Even though part of product data can be available directly from the existing similar products, there still leaves a great deal of data unavailable. This makes data prediction a valuable work. A method that can predict data of product under development based on the existing similar products is proposed. Fuzzy theory is used to deal with the uncertainties in data prediction process. The proposed method can be used in life cycle design, life cycle assessment (LCA) etc. Case study on current refrigerator is used as a demonstration example.
ANALYSIS AND RESEARCH OF COMPUTER-AIDED MODEL OF HIP JOINT BASED ON REVERSE ENGINEERING
2003, 17(3).
[Abstract](2129) [PDF 89KB](63)
Abstract:
Former research work about the modeling of hip joint focus on the upper segment of femoral, and assumes the acetabulum cup is sphere concave, and the acetabulum prostheses is semisphere. A method of acquiring the point data on the surface of the hipbone using the reverse engineering technology is presented. After analyzing the acetabulum surface fitting error, a rotation ellipsoid CAD model is applied to fit the acetabulum surface, and then opti-mization technique is used to find the geometric parameters of the model. The fitting error between the sphere and rotation ellipsoid is compared and gets the result that the fitting error of rotation ellipsoid is smaller than sphere, and the rotation ellipsoid can describe the shape of the acetabulum better.
STUDY ON HU-MAN-COMPUTER SYSTEM FOR STABLE VIR-TUAL DISASSEMBLY
2003, 17(3).
[Abstract](2126) [PDF 112KB](71)
Abstract:
The cooperative work between human being and computer based on virtual reality (VR) is investigated to plan the disassembly sequences more efficiently. A three-layer model of human-computer cooperative virtual disassembly is built, and the corresponding human-computer system for stable virtual disassembly is developed. In this system, an immersive and interactive virtual disassembly environment has been created to provide planners with a more visual working scene. For cooperative disassembly, an intelligent module of stability analysis of disassembly operations is embedded into the human-computer system to assist planners to implement disassembly tasks better. The supporting matrix for stability analysis of disassembly operations is defined and the method of stability analysis is detailed. Based on the approach, the stability of any disassembly operation can be analyzed to instruct the manual virtual disassembly. At last, a disassembly case in the virtual envi-ronment is given to prove the validity of above ideas.
OPTIMUM DESIGN AND NON-LINEAR MODEL OF POWERPLANT HYDRAULIC MOUNT SYSTEM
2003, 17(3).
[Abstract](2132) [PDF 78KB](62)
Abstract:
6–DOF non-linear mechanics model of powerplant hydraulic mount system is established. Optimum design of the powerplant hydraulic mount system is made with the hydraulic mount parame-ters as variables and with uncoupling of energy, rational disposition of nature frequency and minimum of reactive force at mount's location as objective functions. And based on the optimum design, software named ODPHMS (optimum design of powerplant hydraulic mount system) used in powerplant mount system optimum design is developed.
OPTIMIZATION STUDY IN MANUFACTURING PROCESS FOR PC/ABS BLENDS
2003, 17(3).
[Abstract](2152) [PDF 108KB](204)
Abstract:
The optimization of injection molding process for polycarbonate/acrylonitrile-butadiene-styrene blends is studied using Taguchi method and principal component analysis. Four controllable process factors are studied at three levels each in the manufacturing process. The orthogonal array is conducted to determine the optimum process factor/level combination for single auality of mechanical properties to a set of uncorrelated components and to evaluate a comprehensive index for multi-response cases. Then the optimum process factor/level combination for multiple qualities can be determined. Finally the analysisof variance is used to find out the most influential injection molding parameter for single and multiple qualities problems.