Volume 39,Issue 4,2016 Table of Contents

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  • 1  Comparison of modeling methods for a leaf spring with gradually changing stiffness
    XU Zhongming JIN Xin HE Yansong ZHANG Zhifei XIA Xiaojun
    2016, 39(4):1-7. DOI: 10.11835/j.issn.1000-582X.2016.04.001
    [Abstract](1603) [HTML](337) [PDF 3.29 M](1153)
    Abstract:
    According to GB/T 19844-2005, the Chinese national standard of leaf spring, a certain type of leaf spring with gradually changing stiffness was chosen as the research object to compare the superiority of the present modeling and calculation methods of the stiffness of leaf springs. The finite element model and the discrete beam model of the research object were established by using the finite element software Hypermesh and the multi-body dynamics software Adams, respectively. Then, the stiffness of the leaf spring was obtained through simulation. At the same time, the traditional methods of calculating the stiffness of leaf springs through common curvature and concentrated load were also used to calculate the stiffness of the research object, respectively. We compared the simulation stiffness and the calculated stiffness with the test stiffness, and found the stiffness of the discrete beam model is closer to the test stiffness for this leaf spring.
    2  Characteristics of electro-hydraulic proportional cartridge inserted valve based on flow amplifier
    HUANG Jiahai GUO Xiaoxia LI Taotao QUAN Long ZHANG Yong WANG Shengguo
    2016, 39(4):8-15. DOI: 10.11835/j.issn.1000-582X.2016.04.002
    [Abstract](1352) [HTML](499) [PDF 4.36 M](972)
    Abstract:
    Cartridge inserted valves are widely used in hydraulic applications because of their large flow capacities, simple structure and low cost. In this paper, a two-stage cartridge inserted proportional throttle valve was investigated. The main stage of the two-stage poppet type proportional throttle valve is based on flow amplification principle, and a single-stage servo proportional direction valve is used in its pilot stage. We first established a simplified mathematical model, and obtained the qualitative expressions under simplified conditions. Then, we set up a simulation model of the proportional throttle valve by means of SimulationX, and verified the correctness of the model with experimental data. Finally, we used the verified simulation model to analyze the performance of the proportional throttle valve. The results show that there is a dead zone and time lag of the output flow and the flow gain of the main stage is variable. The performance of the proportional throttle valve is affected by the underlap and the area gradient of the feedback slot, the volume between the pilot and the main stages, and flow capacity of the pilot stage, etc.
    3  A dynamic behavior optimization method of windpower speed-increase gearbox
    LIN Tengjiao SONG Jianjun MENG Lingkuan CHEN Bingkui
    2016, 39(4):16-23. DOI: 10.11835/j.issn.1000-582X.2016.04.003
    [Abstract](1311) [HTML](347) [PDF 3.72 M](1205)
    Abstract:
    A finite element vibration analysis model of speed-increase gearbox was established, and modal analysis of gear system has been performed by adopting Lanczos method. Considering the time-varying mesh stiffness, tooth error and impact exaction, we used the direct integration method to obtain the vibration response of surface nodes of gearbox. Taking twelve main structure parameters on the housing as the design variables, the volume of the gearbox as the state variable, RMS of vibration acceleration on the surface of the gearbox as the objective function, we used the zero order and the first order optimization method to acquire the optimal solution of design variables. The results indicate that resonance phenomenon doesn't occur and the gearbox satisfies the static condition both before and after optimization. The objective function has reduced by 37.5%, and significant reduce of vibration response of the computing points of the gearbox can also be found after optimization, and the maximum reduction is 54%.
    4  Heat transfer performance optimization of direct-contact heat exchangers
    YANG Bo HUANG Junwei WANG Huitao WANG Shibo XU Jianxin
    2016, 39(4):24-31. DOI: 10.11835/j.issn.1000-582X.2016.04.004
    [Abstract](1306) [HTML](449) [PDF 2.33 M](1272)
    Abstract:
    A performance optimization model of direct-contact heat exchangers was established, in which the volumetric heat transfer coefficient was used as objective function, the refrigerant initial flow rate U0, the nozzle diameter di, and the heat transfer oil height Z were used as decision variables. The linear model of bubble swarm and heat transfer performance was used as constraint condition in the optimization model, and the influence of the constraint condition on optimization process and results were mainly analyzed. The genetic algorithm was used to analyze the original model and supplementary model. And the results show that the optimized volumetric heat transfer coefficient of the original model is promoted by 6.7 times compared with that of the original design. The number of iterations of the optimal value in the supplement model is reduced by around 55%, and the optimal value increases by 0.3% compared with those of the original model. Therefore, this constraint condition improves not only the iteration rate, but also the probability of seeking the global optimum, which makes the optimal solution more approximate to the global optimal value.
    5  Application of dielectric parameter numerical experiment toGPR test and detection
    YIN Xiaobo ZHANG Bin DENG Jiping TU Zhengyu LIU Chaoyun
    2016, 39(4):32-40. DOI: 10.11835/j.issn.1000-582X.2016.04.005
    [Abstract](1300) [HTML](453) [PDF 4.04 M](1007)
    Abstract:
    Relative permittivity calibration is an important part of ground penetrating radar (GPR) test and detection, which directly affects the test accuracy of GPR. Conventional core-drilling method uses reflection time and the thickness of core to get wave velocity and approximate permittivity, and often ignores the influence of the conductivity on the radar wave velocity. In order to reduce the errors caused by the single core-drilling method, we used the time domain finite difference method to carry out numerical experiments on the double dielectric parameters of reinforced concrete with different conductivities, investigated the relationship among the relative permittivity, the conductivity and the radar wave velocity of the reinforced concrete from the three aspects of the simulation sections, the single scan signal and the snapshots of Ez component respectively, and obtained the correlation between the double dielectric parameters and the radar wave velocity calibration with cubic interpolation and biharmonic interpolation. Results show the correlation between the double dielectric parameters and the radar wave velocity calibration is a section surface distribution and the conductivity and relative dielectric parameters should to be integrally taken into account in radar wave velocity calibration.
    6  The flexural properties of RC beams strengthened with multi-pointsachored externally unbonded prestressed CFRP sheets
    CHEN Xiaoying ZHUO Jing LI Tangning CHEN Mingzheng ZHU Langtao
    2016, 39(4):41-49. DOI: 10.11835/j.issn.1000-582X.2016.04.006
    [Abstract](1104) [HTML](521) [PDF 3.42 M](831)
    Abstract:
    Three same 7 m span reinforced concrete T-beams were strengthened with an external prestressed strengthening technique. CFRP (carbon fiber reinforced polymer) sheets were not affixed to the beams, but laterally pulled by WSGG (wave-shaped-gear-grip) anchor and gripped at the bottom or two sides of the beams. Two beams were strengthened at two sides, while the other one beam was strengthened at bottom. The flexural propterty test results indicate that the section of the CFRP sheets can be adjusted according to the moment of the beam and the high-strength properties of CFRP materials can be efficiently used. There is no difference in improving the flexural rigidity of the beams either strengthened at two sides or at bottom. The WSGG can anchor the prestressed CFRP sheets well. Based on the test results, we proposed an equation for calculating ultimate load and deflection of beams which are strengthen by externally unbonded prestressed CFRP sheets, and a flexural capacity formula according to the beam plastic hinge zone length limit state of the strengthened beams. And the formula for calculation deflection is derived by considering secondary effects of inertia. Compared with the experimental results, the above formulas are verified and can be used for design.
    7  Study on separation of molybdenum from molybdenum-containing copperconcentrate by oxidizing roasting-leaching
    XIAO Junhui SHI Zhe CHEN Jinhua
    2016, 39(4):50-56. DOI: 10.11835/j.issn.1000-582X.2016.04.007
    [Abstract](1311) [HTML](335) [PDF 2.34 M](1120)
    Abstract:
    An oxidizing roasting-leaching flowsheet was proposed to further separate molybdenum because of complex minerals composition and tightness paragenetic relationship of molybdenum and copper in the molybdenum-containing copper concentrate in western Panzhihua of Sichuan province. Samples were put into the roasting furnace to conduct oxidizing roasting, and sulphide ore was oxidized into CuO, MoO3, Fe2O3, etc. Then, NaOH and H2O were added to react with MoO3, and Na2MoO4 was produced, and leaching residue was taken as the copper concentrate. Study results indicate that copper and molybdenum occur in the form of oxide in the roasting ores. The sulfur content is 0.53% in the roasting ores, and sulfur volatilizes in the form of SO2. The leaching ratio of molybdenum is 94.24% and the copper mass fraction in the copper concentrate(leaching residue) is 24.27% when the roasting temperature is 650℃, roasting time is 120 min, NaOH dosage is 30%, leaching temperature is 60℃, leaching time is 120 min, and leaching liquid-solid ratio is 2:1. The effect of molybdenum separation is obvious.
    8  Simulation analysis on hydrogen reduction shaft furnace
    WANG Chengshan SHI Yanwen LI Dandan FENG Pengfei MU Xiaojing
    2016, 39(4):57-66. DOI: 10.11835/j.issn.1000-582X.2016.04.008
    [Abstract](1395) [HTML](410) [PDF 4.32 M](1131)
    Abstract:
    A mathematical model for ore reduction mainly by H2 in shaft furnace was established by a set of conservation equations of materials and heat, and other constraint conditions. All consumptions and productions could be calculated if the composition of N2, the value of V(CO)/V(H2), the metallization ratio of DRI, the temperature of input gas, etc. were given. It shows that the input gas can be reduced from 1650 N·3 for H2 reduction to 1200 N·m3 by CO addition. When the volume ration of CO to H2 V(CO)/V(H2)was 0.6, the energy utilization ratio of shaft furnace was maximum without N2 addition; when V(CO)/V(H2)=0.3, the optimum composition of N2 was 11%; when V(CO)/V(H2)=0, the optimum composition of N2 was 25%. The N2 addition may result in H2 consumption, but could not reduce the total input gas. The simulation will provide reference to process design, operation and energy saving.
    9  The progress and the new profile design of oxygen blast furnace
    ZHANG Wei YU Xiaobing LI Qiang QI Yuanhong ZOU Zongshu
    2016, 39(4):67-81. DOI: 10.11835/j.issn.1000-582X.2016.04.009
    [Abstract](1204) [HTML](627) [PDF 5.07 M](1808)
    Abstract:
    The current researches and development trends of oxygen blast furnace process were summarized and discussed from the perspectives of mathematical model, laboratory experiment and industrial trial. Moreover, the profile design was discussed in this paper. The results show that proper direct reduction degree and thermal reserve temperature should be determined or used in the static simulation of blast furnace process. Meanwhile, compared with conventional blast furnace, the change of productivity, the change of heat loss, the limit of coal injection and the problem of N2 accumulation due to top gas recycling etc. should be all considered. It concluded the problems existing in the multi-dimensional kinetic models and multi-objective optimization models of oxygen blast furnace. Nevertheless, are pointed out future mathematical simulation trend of these two kinds of models. The profile designs including furnace height, bosh angle and shaft angle, and tuyeres were analyzed based on the characteristics of oxygen blast furnace process described in literatures.
    10  Influence and dynamics analysis of MgO content on the desulfurization of blast furnace slag with high Al2O3 content
    SUN Changyu CHEN Yachun LI Jing WANG Qi LIU Xiaohong SHENG Xingxing
    2016, 39(4):82-87. DOI: 10.11835/j.issn.1000-582X.2016.04.010
    [Abstract](1162) [HTML](372) [PDF 2.13 M](952)
    Abstract:
    Al2O3 content will inevitably rise in blast furnace slag as iron ore with high alumina content is continually used, and then metallurgical properties of the blast furnace slag will be certainly impacted. In order to research the effect of MgO content on the desulfurization ability and the desulfurization dynamics of the blast furnace slag with high alumina content, we studied the slag with MgO content of 5%, 9% and 13%, respectively. The results show the MgO content has different effect on the viscosity and the desulfurizaton ability of the slag with high alumina content, and can greatly change the desulfurization rate. The higher the MgO content is, the lower the viscosity and the greater the desulfurization speed is. The desulfuration rate reaches the maximum when the MgO content in the slag is 9%. Both the viscosity and the desulfurization ability are preferable when the MgO content is 9% in the slag, the Al2O3 content is 17% and the basicity is equal to 1.1.
    11  Study on progressive destruction model and constitutive model of red sandstone under limiting shear creep
    ZHAO Hongbao LI Huahua HU Guilin
    2016, 39(4):88-95. DOI: 10.11835/j.issn.1000-582X.2016.04.011
    [Abstract](1065) [HTML](327) [PDF 4.35 M](762)
    Abstract:
    Taking square rock block of red sandstone as research object, we studied all of progressive properties, process and model of destruction of red sandstone under restrictive shear and restrictive shear creep with a self-designed shear creep experimental device of coal or weak rock, a monitor software of coal or rock micromechanics properties and ultrasonic test equipment. The results show that apparent progressive property of red sandstone samples is shown under condition of restrictive shear and restrictive shear creep. The decrease extent of ultrasonic wave velocity in red sandstone samples is samller than those in most of the testing process, and the significantly decrease extent is only shown near the destruction of the sample. The destruction process contains four stages:key fracture plane forms firstly, then abundant secondary micro-fractures forms, and these secondary micro-fractures develope and interconnect, and finally the friction on shear plane is overcome and burst destruction occurs and the main large crack appears in beneath of samples. The development process of destruction is progressive, and the destruction model is burst. A constitutive model that can be used to express the properties of progressive destruction of red sandstone is proposed.
    12  A novel method to measure the velocity of premixed abrasive jet
    ZUO Weiqin LU Yiyu LIU Mingju HAO Fuchang BAI Yapeng
    2016, 39(4):96-102. DOI: 10.11835/j.issn.1000-582X.2016.04.012
    [Abstract](1043) [HTML](349) [PDF 2.57 M](963)
    Abstract:
    The ultra-intense hitting power of abrasive water jet is mainly provided by high-speed abrasives. So measuring the abrasive velocity is the base to research the hitting power and the erosion mechanism. To overcome the shortcomings of traditional research methods, a new testing method was proposed. The method uses the PIV(particle image velocimetry)combined with center recognition program to gain the abrasive velocity, and can test the high velocity of abrasive jet without contacting. Furthermore, the influence law of nozzle structure on the abrasive velocity was proceeded with this method. The results show that increasing the length of straight segment in a certain range is conducive to improve the abrasive velocity, because the abrasives were in the state of obvious accelerated motion in the end of the straight segment. Increasing the length of convergence section in a certain range is conducive to improve the abrasive velocity, but the increase amplitude is not very large. When the convergence angle is too large, liquid phase accelerates slowly in the first half of convergence section but accelerates sharply in the second half of convergence section. Then the acceleration of abrasives lags behind that of liquid phase, and thus the abrasive velocity is decreased.
    13  Optimization of mining sequence based on coordination mining technology between two adjacent open pits
    LIU Chuang BAI Runcai LIU Guangwei CAO Bo
    2016, 39(4):103-111. DOI: 10.11835/j.issn.1000-582X.2016.04.013
    [Abstract](1365) [HTML](302) [PDF 3.00 M](942)
    Abstract:
    To resolve the contradiction between long-term economic benefits generated by coordinating mining technology and short-term profits affected by changing mining sequences, we used the basic principles of surface mining to optimize the mining sequences of two adjacent open pits. We first analyzed the characteristics of coordination mining technology and influencing factors for unifying stopes, then proposed an optimization criterion about mining district dividing schemes, also built optimization models about forms of stope and dump and gave a method to calculate the time of unifying stopes, and finally proposed an method to optimize forms of stope and dump after stopes were unified. The proposed models were verified through an engineering example. The results show that optimizing forms of stope and dump can reduce overburden, increase internal dump space reasonably, and enhance economic benefits of open pits in the process of unifying stopes.
    14  Determination of H2O2 in rainwater using flow injection chemiluminescence enhanced by ZnO nanoparticles
    CHEN Hua CHEN Zuqin YANG Min XIE Xue
    2016, 39(4):112-117. DOI: 10.11835/j.issn.1000-582X.2016.04.014
    [Abstract](1222) [HTML](394) [PDF 1.71 M](833)
    Abstract:
    Based on the fact that the ZnO nanoparticles (ZnO NPs) can enhance the weak chemilu-minescence (CL) of the luminol-H2O2 system, a simple, fast and sensitive flow injection CL method was developed for the determination of H2O2 in rainwater. Experimental parameters affecting CL were optimized, including pH and concentrations of ZnO NPs, luminol and H2O2. Under optimal conditions, the logarithm of CL peak area (lg A) is linear with the logarithm of the concentration (lg c) of H2O2 when the concentration of H2O2 ranges from 0.06 to 20 μmol/L and its limit of detection is 0.016 μmol/L(3σ). The method has been successfully applied to the determination of H2O2 in rainwater, giving recovery rate in the range of 95%~102% and RSD (n=11) of 2.41%.
    15  Study on the influence of Cu2+ adsorption onto activated sludge in the presence of HA
    LIU Zhiping SHI Ping FANG Fang WU Wenhui GOU kai
    2016, 39(4):118-126. DOI: 10.11835/j.issn.1000-582X.2016.04.015
    [Abstract](1238) [HTML](327) [PDF 2.78 M](887)
    Abstract:
    To investigate the interaction among HA, Cu2+ and activated sludge, we researched the influence of adsorption time, pH, Cu2+ concentration and temperature on the adsorption of Cu2+ onto activated sludge in the presence of HA, respectively, and analyzed the adsorption mechanism from the aspects of thermodynamics, sludge characteristics and Fourier transform infrared spectroscopy(FTIR) before and after adsorption. The results show that the equilibrium time of the adsorption of Cu2+ onto activated sludge in the presence of HA is 90 min under the conditions of pH, the concentrations of activated sludge, Cu2+ and HA are 6, 2 g/L, 50 mg/L and 50 mg/L, respectively. When the adsorption equilibrium is reached, the adsorption capacity of Cu2+ is 45.98 mg/L and the adsorption rate is 91.96%. It's also found that HA can weaken the toxicity of Cu2+to activated sludge. The performance of activated sludge absorbing Cu2+ mainly depends on the hydrogen bond force and the dipole force, and the functional groups of polysaccharide lipid C-O and benzene ring C-H also play a major role in the process of adsorption.
    16  Simulation and field measurement of the lateral energy fraction in hall
    WANG Hongwei ZHANG Long
    2016, 39(4):127-132. DOI: 10.11835/j.issn.1000-582X.2016.04.016
    [Abstract](1293) [HTML](851) [PDF 2.11 M](1387)
    Abstract:
    The lateral energy fraction in hall is an important objective factor of spatial impression, and it is usually simulated by computer simulation. We first used MKH800 to measure the lateral energy fractions at the corresponding positions of a real hall. Then, we established a 3D model of the hall with ODEON 6.5 to simulate the lateral energy fractions at the receiving points. Finally, the simulated lateral energy fractions were compared with the measured ones. The comparison results show that the simulation values are larger than the measured ones. The deviation of the simulated values is small in the front part of the seating area, and it is large in the middle and back part of the seating area in front of the stage. The reason for the deviation is that the diffusion coefficient of ODEON is not related to the areas' character, and the diffusion coefficient of each frequency band can not be separately defined in this software. Therefore, in order to accurately predict the indoor acoustics, it is recommended to use architectural acoustic scale model to measure lateral energy fractions.
    17  Design and process simulation of high voltage P-channel VDMOS
    PU Shi DU Lin ZHANG Dexi
    2016, 39(4):133-138. DOI: 10.11835/j.issn.1000-582X.2016.04.017
    [Abstract](1397) [HTML](850) [PDF 2.10 M](1020)
    Abstract:
    As one of core devices in modern power semiconductor, P-channel VDMOS device has not been well researched for its narrow applications. We focused on the development of P-channel VDMOS device, designed a P-channel VDMOS with breakdown voltage over -200 V, including the active region cell structure and the junction termination structure, and developed a non-self-aligned progress flow for P channel VDMOS. Simulation results show that the breakdown voltage of the device is over -200 V and the threshold voltage is -2.78 V. The results meet the design requirements, and the research can provide references for the device fabrication.
    18  Wind speed time series prediction based on associative network
    YANG Yunong XIU Chunbo
    2016, 39(4):139-146. DOI: 10.11835/j.issn.1000-582X.2016.04.018
    [Abstract](986) [HTML](378) [PDF 1.76 M](1146)
    Abstract:
    In order to improve the reliability of wind speed series prediction, a new associative network was constructed to predict the wind speed series with chaotic characteristics. Stored sample patterns were constructed according to the similarity measure of the volatile of the wind speed series. Utilizing the correlation information contained in the stored sample patterns, the network adopts an unsupervised learning algorithm to complete the weight training. One step or multi-step prediction of the wind speed series which have self-similarity can be completed by the associative network. Compared with the conventional forward neural network, the prediction mechanism of the associative prediction network is explicit, and the prediction result is uniqueness. The network can also give one step or multi-step prediction results simultaneously in once calculation. Simulation results show that the associative network has good prediction performance, and can be applied to predict dynamically the wind speed series.
    19  The application of SA-PSO to CNN edge detection template design
    ZHANG Jie TIAN Yuan DENG Shaojiang
    2016, 39(4):147-153. DOI: 10.11835/j.issn.1000-582X.2016.04.019
    [Abstract](1311) [HTML](347) [PDF 1.92 M](812)
    Abstract:
    In this paper, a synthesis procedure of cellular neural networks (CNNs) template design for edge detection is proposed. This method combines simulated annealing and particle swarm optimization (SA-PSO) to search template values. In the process of searching, annealing temperature is used to adjust kick probability and roulette is adopted to select global optimal replacement value. In this way, trapping into local optimum problems of PSO can be effectively avoided. Moreover, in order to guarantee stable outputs of CNNs, properties of CNN feedback template obtained in previous researches are used to constraint particle solution space. Simulation results show CNN templates designed by this method are efficiency in edge detection.
    20  Investigation of probabilistic design method for ceramic tile thermal protection system
    QU Qiang ZHU Wenxiang XIN Jianqiang YAO Jianyao
    2016, 39(4):154-161. DOI: 10.11835/j.issn.1000-582X.2016.04.020
    [Abstract](1440) [HTML](694) [PDF 2.66 M](1280)
    Abstract:
    A probabilistic sizing tool for rigid ceramic tiles thermal protection system (TPS) for hypersonic flight vehicles was proposed based on finite element and Monte Carlo methods. A two-dimensional probabilistic finite element model was developed, in which the uncertainties of thermal conductivities, specific heat capacities, emissivity and the thickness of TPS were considered. The temperature distributions of TPS were obtained, and the sensitivities of the input random parameters were also investigated. Based on the statistical results, the thermal reliability of ceramic tile TPS was evaluated. The numerical example indicates that the thermal reliability can be improved by increasing the thickness of ceramic tile or strictly controlling its manufacture tolerance. The proposed method could be helpful to design highly reliable TPS with minimum weight.
    21  Nodes fault diagnosis algorithm based on sensor network synchronous state
    ZHANG Ying QU Jianfeng REN Hao
    2016, 39(4):162-170. DOI: 10.11835/j.issn.1000-582X.2016.04.021
    [Abstract](1191) [HTML](368) [PDF 4.64 M](791)
    Abstract:
    First, the concept of complex network synchronous state was introduced in this paper. Then a sensor network varying with time was defined by taking the data measured by sensors as nodes, and the dynamic mechanics of the sensor network was quantitatively described with mathematical analysis method. Finally, the mathematical definition, the calculation method and the physical meaning of the sensor network synchronous state were given. The above theoretical derivation show synchronous state can globally assess the health of the sensor network. The couple matrix A=(aij)N×N of complex network was defined by the distance relevance of the measured data. And the left eigenvector (ξ12,...,ξN)corresponding to the zero feature of the matrix was used to character the local details of sensor network nodes. Then, a node fault diagnosis algorithm was derived based on sensor network synchronous state. A complex network which consists of 100 sensors was experimentally simulated. We collected the measured data in 60 s during the stable operation with each length of 5000, and there were 3 sensors in intermittent gain fault state to verify the effectiveness of the proposed method. The simulation results show that the proposed method can not only track the work state of the whole sensor work and monitor the faults of each node in real-time, but also distinguish the abnormal data caused by the change of external objects or by sensor faults through combining the relevance between the node faults. The proposed algorithm can provide a feasible research idea of assessing the global state of the sensor network and monitoring the partial fault of network nodes, and it's hoped the algorithm can provide references to researchers in related fields.

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