共查询到20条相似文献,搜索用时 15 毫秒
1.
This paper is a supplement to “Trends in the Development of Advanced Manufacturing Technology” (Yang and Wu in Chin. J. Mech. Eng., 39: 73, 2003) but delves deeper into it. It first points out the strategic status of manufacturing industry in state development. Then,
a detailed analysis is given on the features and trends in the development of advanced manufacturing technology in a total
of 12 points from three aspects: “precision,” “extreme,” and “culture” from the aspect of the product itself; “green,” “rapidness,”
“saving,” and “efficiency” during the manufacturing process; and “digit,” “auto,” “integration,” “networking,” and “intelligence”
in view of the manufacturing method. In addition, it emphasizes that all the above aspects should be based on two base points:
“manufacture” and “machinery.” Finally, it puts forth the guiding ideologies for the development of advanced manufacturing
technology and the aspects China should give priority to in development, while stressing on the principles of independence,
innovation and “human orientation.” 相似文献
2.
Zhanshe GUO Yihui WU Yonggang MENG Dezhi ZHENG 《Frontiers of Mechanical Engineering in China》2008,3(1):76-80
To satisfy the needs of the high deep-width ratio and thickness of a planar micromotor’s stator windings, a process method
to produce an electromagnetic planar micromotor with AZ4903 is proposed. Optimum relationships, such as the desired rotation
speed vs. thickness of the coating process, and the temperature vs. time of pre-baking, are obtained. The appropriate time
of lithography and development are also achieved. The thickness of the produced windings is 40 μm with ideal perpendicularity.
Finally, stators and rotors are fabricated. The rotation speed and pull-out torque of the micromotor are tested. The experiment
proved that the micromotor worked with a steady speed and a low ripple of pull-out torque.
__________
Translated from J Tsinghua Univ (Sci & Tech) 2005, 45(8): 1062–1065 [译自: 清华大学学报(自然科学版)] 相似文献
3.
Directional solidification of metal-gas eutectic (Gasar) is a novel process for making regular porous metals. This process
is based on a solid-gas eutectic reaction involving a gaseous medium and a metal or ceramic phase. The process easily controls
the porosity, the pore size, the pore orientation, and the pore morphology when the melting and solidifying conditions are
varied in a wide range. The latest progress and our research work are reviewed in this paper.
Translated from Special Casting and Nonferrous Alloys, 2005, 25(1):1–4 [译自: 特种铸造及有色合金] 相似文献
4.
A dynamical sliding-mode controller is devised to track the output of mobile manipulators. During the investigation, firstly
a reduced dynamic model considering the dynamics of the driving motor is developed for mobile manipulators. Then, the system
is decomposed into four lower-dimensional subsystems by means of diffeomorphism and nonlinear input transformation. Moreover,
a design method of the dynamical sliding-mode controller that is applied to the output tracking of mobile manipulators is
proposed. The simulation results indicate that the dynamical sliding-mode controller can not only track the given trajectory
correctly but also reduce the chattering of sliding-mode control system considerably.
__________
Translated from Journal of South China University of Technology (Natural Science Edition), 2006, 34(6): 29–33 [译自: 华南理工大学学报 (自然科学版)] 相似文献
5.
6.
Zhang Jianming Zhang Weigang Yang Bing Wang Yawei 《Frontiers of Mechanical Engineering in China》2007,2(4):439-441
A force model of a control valve of injector is set up, and the changes of the fluid damping clearance are investigated on
the basis of the results of the computational fluid dynamics (CFD) and the experiments of control valve of injector. Results
indicate that a damping clearance of 0.02–0.03 mm between the poppet and the valve guide is the most sufficient to dampen
any excessive control valve poppet bouncing.
__________
Translated from Journal of Shanghai Jiaotong University, 2006, 40(6): 1031–1034 [译自: 上海交通大学学报] 相似文献
7.
In allusion to fatigue life of a tracked vehicle torsion bar, a virtual prototype model of the tracked vehicle suspension
system including a flexible torsion bar was built based on dynamic simulation software—ADAMS. Node force and stress results
of the torsion bar from last step simulation were acquired; taking into account the material characteristics and influential
factors, fatigue life of the flexible body of the torsion bar was predicted. Engineering results can be acquired through the
contrast of the result of virtual test and statistical fatigue.
__________
Translated from Journal of Academy of Armored Force Engineering, 2006, 20(1): 44–47 [译自: 装甲兵工程学院学报] 相似文献
8.
Li Zhinong He Yongyong Chu Fulei Wu Zhaotong 《Frontiers of Mechanical Engineering in China》2007,2(1):46-49
A blind identification method was developed for the threshold auto-regressive (TAR) model. The method had good identification
accuracy and rapid convergence, especially for higher order systems. The proposed method was then combined with the hidden
Markov model (HMM) to determine the auto-regressive (AR) coefficients for each interval used for feature extraction, with
the HMM as a classifier. The fault diagnoses during the speed-up and speed-down processes for rotating machinery have been
successfully completed. The result of the experiment shows that the proposed method is practical and effective.
__________
Translated from Journal of Tsinghua University (Science and Technology), 2005, 45(8): 1 036–1 039 [译自: 清华大学学报(自然科学版)] 相似文献
9.
Fei Yanqiong Dong Qinglei Zhao Xifang 《Frontiers of Mechanical Engineering in China》2007,2(1):116-119
This paper proposes a novel, hermaphroditic, and lattice self-reconfigurable modular robot. Each module is composed of a center
body—a cubic part and six sides that can rotate independently. There are two holes and two extensible pegs on each side. The
rotary motion of each side and the extensible motion of the pegs are generated by a motor connected to a reducer, using a
cone-shaped gear, belt, clutch, etc. The structure of the module is compact, and has space to extend further.
__________
Translated from Journal of Shanghai Jiaotong University, 2005, 39(6): 877–879 [译自: 上海交通大学学报] 相似文献
10.
This paper employs a shallow water model and the finite element method to approximate periodical flows of a micropump to a
two-dimensional thickness-averaged flow. A liquid-solid coupled system equation of the micropump is presented. Through the
mode analysis of the liquid-solid coupled system, the first-order natural frequency, diaphragm vibration shape and amplitude-frequency
relationship are obtained. The vibration response of the diaphragm is calculated when an external electric field is applied.
Based on the thickness-averaged flow equation, the periodical flow of the micropump is studied using the finite volume method
to investigate the flow behavior and flow rate-frequency characteristics. Numerical results indicate that an optimal working
frequency can be obtained, at which the flow rate of the micropump achieves the maximum when the external electric voltage
is fixed.
__________
Translated from Journal of Hydrodynamics, 2006, 21(4): 512–518 [译自: 水动力学研究与进展] 相似文献
11.
A. N. Magunov A. O. Zakharov B. A. Lapshinov 《Instruments and Experimental Techniques》2012,55(1):134-139
Recording of a sequence of thermal-radiation spectra allows determination of a nonstationary temperature T(t) without using the data on the emissivity of an object. For a КЭФ-4.5 silicon single crystal heated with radiation from a
continuous-wave Nd:YAG laser (λ = 1.064 μm), sequences of hundreds of emission spectra in wavelength ranges of λ = 350–760
nm and λ = 650–1000 nm were recorded at a signal storage time of a CCD array of τ = 15–35 ms and a frequency of recording
spectra of f ≈ 30–66 Hz. The spectra were automatically processed, and the dependences of the crystal temperature on the time after the
irradiation onset were obtained in the range T ≈ 1100–1450 K. 相似文献
12.
This paper presents an optimization model for rotor blades of horizontal axis wind turbines. The model refers to the wind
speed distribution function on the specific wind site, with an objective to satisfy the maximum annual energy output. To speed
up the search process and guarantee a global optimal result, the extended compact genetic algorithm (ECGA) is used to carry
out the search process. Compared with the simple genetic algorithm, ECGA runs much faster and can get more accurate results
with a much smaller population size and fewer function evaluations. Using the developed optimization program, blades of a
1.3 MW stall-regulated wind turbine are designed. Compared with the existing blades, the designed blades have obviously better
aerodynamic performance.
__________
Translated from Journal of Shantou University (Natural Science), 2006, 21(1): 44–49 [译自: 汕头大学学报 (自然科学版)] 相似文献
13.
Yinnan Yuan Deqing Mei Zhong Wang Tian Zhang 《Frontiers of Mechanical Engineering in China》2008,3(2):189-192
The combustion and heat release of engines using diesel fuel and bio-diesel fuel have been investigated. The results illustrate
that the combustion happens in advance and the ignition delay period is shortened. The initial heat release peak declines
a little, the corresponding crankshaft angle changes in advance, and the combustion duration is prolonged. The economic performance
and emission features of diesel engines using diesel fuel and bio-diesel fuel are compared. The results also show that the
specific fuel consumption of bio-diesel increases by about 12%. The emissions, such as CO, HC, and particulate matter decrease
remarkably whereas NO
x
increases a little.
__________
Translated from Journal of Jiangsu University (Natural Science Edition), 2006, 27(3): 216–219 [译自: 江苏大学学报(自然科学版)] 相似文献
14.
The operating technique and benefits of three-crucible differential thermal analysis are discussed. Using this method, the
temperatures and heat effects of iron phase transitions were determined: 773±3°C (α→β), 923±4°C and 10.2±0.8 J/g (β→γ), 1400±3°C
and 17.0±1.0 J/g (γ→δ), and 1539±4°C and 250±20 J/g (°→liquid). The temperature of (α→β) beryllium transition (1274±5°C),
its melting point (1292±5°C), and the interval of BCC Be (18±5°C) were also measured. The total heat of both trnasitions is
15.1±0.7 kJ/mol, composed of the heat of the α→β transition (7.5±0.4 kJ/mol) and the heat of melting (7.6±0.4 kJ/mol). ***
DIRECT SUPPORT *** A31DG005 00013 相似文献
15.
Damage detection by using the changes of dynamic parameters is a conventional damage diagnosis method, however, some indices
are not sensitive enough to the most structural damages. In this study, the analytical data of displacement modes of truss
structure are obtained by using the finite element analysis soft—ANSYS. The mode analysis technique for the axial strain change
of any stick is used to detect the steel trusses with different damages. The analytical results show that the damage location
and degree of the truss stick can be effectively diagnosed by means of the axial strain change.
__________
Translated from Journal of Wuhan University of Technology, 2006, 30(2): 285–288 [译自: 武汉理工大学学报] 相似文献
16.
A. N. Magunov 《Instruments and Experimental Techniques》2010,53(6):910-914
The temperature of opaque objects with the emissivity ɛ(λ) depending on the wavelength can be rather precisely determined
with an error of ≤1–5% from their heat emission spectrum using the model of a gray body ɛ = const(λ). This method is based
on the much more strong spectral dependence of the heat emission intensity I(λ) within the short-wavelength region in comparison with that of the emissivity ɛ(λ). At relatively low temperatures T ≤ 3000–4000 K, any opaque object radiates as a gray body in the short-wavelength spectrum region (λ ≤ 350–400 nm), even if
it appreciably differs from a gray body in its optical properties. An experimental heat emission spectrum of tungsten (T ≈ 1970 K), for which the influence of the emissivity manifests itself in the long-wavelength region (λ > 580 nm), is given. 相似文献
17.
Chen Wei Yang Jichang Wu Xiaofeng Lu Dun Guo Weigang 《Frontiers of Mechanical Engineering in China》2007,2(4):399-403
Fracture is a common defect in sheet metal forming and it is essentially caused by tensile instability. This paper analyzes
some experiments and theories for building forming limit diagrams of sheet metal and points out the advantages and disadvantages
of current experiments and theories. According to this, a method that integrates the finite element simulation and experiment
was used to research the forming limit diagrams of the sheet metal under complex strain paths. Taking the rear hanger that
undergoes twice stamping as an example, the strain paths of the dangerous point of the rear hanger is investigated. Finally,
the forming method of the rear hanger is confirmed. Results indicate that finite element method (FEM) can achieve the complex
strain paths and different strain paths will have great impacts on the result of the sheet metal forming.
__________
Translated from Journal of Jiangsu University (Natural Science Edition), 2005, 26(4): 289–293 [译自: 江苏大学学报 (自然科学版)] 相似文献
18.
To conveniently carry out the pipeline leak experiment in a laboratory, leak acoustic signals are simulated by using the converse
piezoelectric effect of a piezoelectric transducer (PZT) cylindrical phase modulator. On the basis of the piezoelectric equations
and electromechanical equivalence principle, the transfer function of a PZT cylindrical phase modulator is delivered. A PZT
cylindrical phase modulator is designed, and the numerical simulation is conducted. Results prove that the PZT cylindrical
phase modulator can effectively simulate leak acoustic emission signals when the frequency is lower than 25 KHz.
__________
Translated from Journal of Beijing University of Technology, 2006, 32(8): 683–687 [译自: 北京工业大学学报] 相似文献
19.
Hu Yida Li Dazhai Yang Yang Sun Xuguang 《Frontiers of Mechanical Engineering in China》2007,2(2):205-209
To enhance the effect of robotic microsurgery, the microsensors are integrated on the robot’s end-effector. On the basis of
the requirements presented for the integration design, measuring mechanism for the robotic end trephine’s force and cutting
depth are studied. Force microsensor and position microsensor are used to measure surgical information of the force and depth.
Measuring mechanism was achieved by means of linear sliding bearing and differential measuring structure. The sensor data
board was developed. With the power spectral estimation of sensor data, two digital filtering methods are proposed, to help
eliminate the interference to the original microsensor signal. They are the filtering method of lowpass-bandstop serial structure
suitable for a PC, and a shift average filtering algorithm suitable for the sensor data board, respectively. The experimental
results show that the integration of microsensors for microsurgery robot’s end-effector can satisfy the design requirements,
and the robotic end trephine can accurately fulfill the surgical task of corneal cutting.
Translated from Journal of Beijing University of Aeronautics and Astronautics, 2005, 31(7): 794–798 [译自: 北京航空航天大学学报] 相似文献
20.
The cutting heat dissipation in chips, workpiece, tool and surroundings during the high-speed machining of carbon steel is
quantitatively investigated based on the calorimetric method. Water is used as the medium to absorb the cutting heat; a self-designed
container suitable for the high-speed lathe is used to collect the chips, and two other containers are adopted to absorb the
cutting heat dissipated in the workpiece and tool, respectively. The temperature variations of the water, chips, workpiece,
tool and surroundings during the closed high-speed machining are then measured. Thus, the cutting heat dissipated in each
component of the cutting system, total cutting heat and heat flux are calculated. Moreover, the power resulting from the main
cutting force is obtained according to the measured cutting force and predetermined cutting speed. The accuracy of cutting
heat measurement by the calorimetric method is finally evaluated by comparing the total cutting heat flux with the power resulting
from the main cutting force.
__________
Translated from Journal of South China University of Technology (Natural Science Edition), 2006, 34(11): 1–4 [译自: 华南理工大学学报(自然科学版)] 相似文献