1997 Vol.10(1)
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1997, 11(1).
Abstract:
The minimum energy consumption theory on the chip flow interference and coordination is illustrated. An oblique cutting mathematical model of the unit cutting edge is established. Based on the established model, the cutting power is optimized from the original cutting data. The different influences of the two factors of the chip flow vector on the consumption of the cutting power are investigated, results showing that the influence of the chip flow speed is stronger than that of the chip flow direction.
The minimum energy consumption theory on the chip flow interference and coordination is illustrated. An oblique cutting mathematical model of the unit cutting edge is established. Based on the established model, the cutting power is optimized from the original cutting data. The different influences of the two factors of the chip flow vector on the consumption of the cutting power are investigated, results showing that the influence of the chip flow speed is stronger than that of the chip flow direction.
1997, 11(1).
Abstract:
The kinematic and dynamic analysis of a three degrees of freedom 3-RPS parallel robot mechanism are presenteed. The Jacobian of the mechanism is a 3 by 6 rectangular matrix. This imposes difficulties on the kinematic analysis of this mechanism. A method to formulate three motion constrain equations which are consistent with the structure of the mechanism is presented, and the close form dynamic model is established for the parallel robot mechanism.
The kinematic and dynamic analysis of a three degrees of freedom 3-RPS parallel robot mechanism are presenteed. The Jacobian of the mechanism is a 3 by 6 rectangular matrix. This imposes difficulties on the kinematic analysis of this mechanism. A method to formulate three motion constrain equations which are consistent with the structure of the mechanism is presented, and the close form dynamic model is established for the parallel robot mechanism.
1997, 11(1).
Abstract:
The problems in the traditional definition of the compressibility and bulk modulus of the fluid are analyzed, and a new definition is put forward. Some problems which can not be explained by traditional definition may be interpreted by the new definition.
The problems in the traditional definition of the compressibility and bulk modulus of the fluid are analyzed, and a new definition is put forward. Some problems which can not be explained by traditional definition may be interpreted by the new definition.
1997, 11(1).
Abstract:
A new technique of wto-way hydro-mechanical ironing is put forward. Theoretical formulas is derived for calculating the forming limit of ironing together with the experiments of two-way hydro-mechanical ironing by three kinds of preforms. When hydraulic pressure reaches 120 Mpa, ironing limit coefficient for turned soft-aluminum preforms reduces from 0.50 to 0.30, from 0.60 to 0.45 for twice-drawn preforms, from 0.60 to 0.40 for annealed twice-drawn preform. The experimental results show that ironing limit coefficient versus hydraulic pressure tends to be the same as the results from theoretical analyses. Thus indicating that the new technique of two-way hydro-mechanical ironing can increase the forming limit of ironing at a single time effectively.
A new technique of wto-way hydro-mechanical ironing is put forward. Theoretical formulas is derived for calculating the forming limit of ironing together with the experiments of two-way hydro-mechanical ironing by three kinds of preforms. When hydraulic pressure reaches 120 Mpa, ironing limit coefficient for turned soft-aluminum preforms reduces from 0.50 to 0.30, from 0.60 to 0.45 for twice-drawn preforms, from 0.60 to 0.40 for annealed twice-drawn preform. The experimental results show that ironing limit coefficient versus hydraulic pressure tends to be the same as the results from theoretical analyses. Thus indicating that the new technique of two-way hydro-mechanical ironing can increase the forming limit of ironing at a single time effectively.
1997, 11(1).
Abstract:
Several typically instantaneous states are invesitigatied in the course of tube inversion, and correspondingly mathematical models are established according to the experimental results of the tube inversion process. By means of the mathematical models, the tube inversion process and the die parameters are successfully determined.
Several typically instantaneous states are invesitigatied in the course of tube inversion, and correspondingly mathematical models are established according to the experimental results of the tube inversion process. By means of the mathematical models, the tube inversion process and the die parameters are successfully determined.
1997, 11(1).
Abstract:
A scanning probe microscope with high resolution and wide measuring range(140μm×140μm) is presented, which is constructed only with six machined components and can measure the nanotopography of magnetic and optical disk substrate of diameter 130 mm directly. By changing the measuring probe, this instrument can work in the multiple operation modes, such as scanning tunneling microscope, atomic force microscope, magnetic force microscope and electrostatic force microscope. Some experimental results, such as the atomic resolution image of graphite, the nanotopogtrphy of optical grating, and ultragrinding surface are given.
A scanning probe microscope with high resolution and wide measuring range(140μm×140μm) is presented, which is constructed only with six machined components and can measure the nanotopography of magnetic and optical disk substrate of diameter 130 mm directly. By changing the measuring probe, this instrument can work in the multiple operation modes, such as scanning tunneling microscope, atomic force microscope, magnetic force microscope and electrostatic force microscope. Some experimental results, such as the atomic resolution image of graphite, the nanotopogtrphy of optical grating, and ultragrinding surface are given.
1997, 11(1).
Abstract:
An accurate calculation of stress field based on elastic-plastic finite element method by means of Siemens computer showed that both hardness difference and coefficient of friction are important factors to affect on fatigue failure of rolling-sliding contact. An experiment on fatigue life of rolling-sliding contact was carried out in condition of various hardness difference by a two-roller-type rolling contact fatigue tester.
An accurate calculation of stress field based on elastic-plastic finite element method by means of Siemens computer showed that both hardness difference and coefficient of friction are important factors to affect on fatigue failure of rolling-sliding contact. An experiment on fatigue life of rolling-sliding contact was carried out in condition of various hardness difference by a two-roller-type rolling contact fatigue tester.
1997, 11(1).
Abstract:
On the basis of discussing about several damping models of electrorheological (ER) fluid, a new damping model is provided which accounts for the yielding phenomena of ER fluids. An improved Fourier series expansion parameter extimation method is used to establish the experimental dynamic model of an ER fluid, which is dispersed by silica gel in silicone oil. The models are verified through experiments and provide good agreeements between predicted and measured responses.
On the basis of discussing about several damping models of electrorheological (ER) fluid, a new damping model is provided which accounts for the yielding phenomena of ER fluids. An improved Fourier series expansion parameter extimation method is used to establish the experimental dynamic model of an ER fluid, which is dispersed by silica gel in silicone oil. The models are verified through experiments and provide good agreeements between predicted and measured responses.
1997, 11(1).
Abstract:
Non-chip machining of a harmonic gears through cold rolling process is put forward. The rolling principle and the flow patern of metal in the process are studied. Both for the rigid gear and the flexible gear some satisfactory results, and a new process of non-chip machining the teeth of a harmonic gear are obtained.
Non-chip machining of a harmonic gears through cold rolling process is put forward. The rolling principle and the flow patern of metal in the process are studied. Both for the rigid gear and the flexible gear some satisfactory results, and a new process of non-chip machining the teeth of a harmonic gear are obtained.
1997, 11(1).
Abstract:
A new method based on genetic algorithms is proposed, which is used to optimize structure designs with mixed continuous and discrete design variables. A scheme representing the mixed variable problems is presented, and a method constructing sub-design space to reduce Gas search region is proposed. This method can deal with strucural optimization problems with stress and displacement constraints and measurement of design variables. Examples are given to demonstrate the high efficiency and robustness of this method.
A new method based on genetic algorithms is proposed, which is used to optimize structure designs with mixed continuous and discrete design variables. A scheme representing the mixed variable problems is presented, and a method constructing sub-design space to reduce Gas search region is proposed. This method can deal with strucural optimization problems with stress and displacement constraints and measurement of design variables. Examples are given to demonstrate the high efficiency and robustness of this method.
1997, 11(1).
Abstract:
Flexible manufacturing systems are formulated as an open queueing network. In the model, machines process jobs with exponentially distributed processing time,carts route jobs to workstations according to a Markov routing policy with exponentially distributed routing timeand blocked jobs are treated in accrdance with a new block mechanism, called "FMS block"mechanism. It is shown that the equilibrium state distrbution of the model has a product-form solution. Based on the product-form solution, system performances can be easily measured.
Flexible manufacturing systems are formulated as an open queueing network. In the model, machines process jobs with exponentially distributed processing time,carts route jobs to workstations according to a Markov routing policy with exponentially distributed routing timeand blocked jobs are treated in accrdance with a new block mechanism, called "FMS block"mechanism. It is shown that the equilibrium state distrbution of the model has a product-form solution. Based on the product-form solution, system performances can be easily measured.
1997, 11(1).
Abstract:
The stability of the linear optimal controlled vehicle suspension system, which contains some nonlinear elements and there is time delay in the control circuit is studide. The stability interval of time delay is determined. The periodic movement of the system is analized by Hopf bifurcatin theorem when time delay is at its critical point. The corresponding simulating results are given.
The stability of the linear optimal controlled vehicle suspension system, which contains some nonlinear elements and there is time delay in the control circuit is studide. The stability interval of time delay is determined. The periodic movement of the system is analized by Hopf bifurcatin theorem when time delay is at its critical point. The corresponding simulating results are given.
1997, 11(1).
Abstract:
Based on radial basis function (RBF) neural networks and the reference operating point, a new approach to fault detection and diagnosis of highly nonlinear system is presented. It studies nonlinear system directly. The effects caused by occurrence of fault can be differed from the ones caused by variance of operating points precisely. Finally the effectiveness of this method is verfied in an aeroplane actuating system.
Based on radial basis function (RBF) neural networks and the reference operating point, a new approach to fault detection and diagnosis of highly nonlinear system is presented. It studies nonlinear system directly. The effects caused by occurrence of fault can be differed from the ones caused by variance of operating points precisely. Finally the effectiveness of this method is verfied in an aeroplane actuating system.