2015 volumne 36 Issue 02
LIU Zhu-li,ZHAO Min-min,MA Peng-peng,QIN Dong-chen
Abstract: For a helical gear vice in a large transmission device,assembly model is created in Solidworks, andthen it is imported into the finite element analysis software ANSYS and stress analysis is contacted. Besides ,the contact stress calculation results and the traditional contact stress calculation results is compared;Finally ,the contact stress reliability in ANSYS is analyzed. The results show that : the helical gear vice actual contactstress is less than the allowable contact stress,and meet the requirements,but its reliability is only 83.6398%, which means by traditional method which only counts the mechanical design safety factor is not e-nough;Besides, from the sensitivity of random factors to detss , we know that increasing driven wheel diametercan improve the reliability effectively.
ZHAO Wei1,WANG Ning-ning1,DUAN Yan-yan1,ZHANG Ming-zhu2
Abstract: When deviating from the expected route in a complex rode condition,the heavy truck easily experiencesa serious accident,because of its heavy lode. In view of the condition of turning of a large lode truck ,the paperapplies the yaw moment technology to control the stability of the truck. The changes of wheel vertical load and theside slip angle will exert an influence on the braking force. Through the analysis of the influence,the article propo-ses the control strategy of controlling the truck to keep traveling track,and the fuzzy controller was designed andsimulated.The result of the simulation shows that,the intelligent tracking control system can improve the trackingability of the truck under curve driving,and has a certain significance to improve the driving safety.
ZHAN Li-hua,CHEN Zhen
Abstract: Pre-treatment ( geometric modeling-grid-boundary conditions-material attribute definition )-analysis-post-processing are needed when the different plate sizes,solid solution, quenching temperature,thermal con-ductivity,stretching rate and other parameters are taken into consideration on the residual stress analysis. Themathematical model is set up for each set of parameters for analysis,repeating operation,the analysis efficien-cy is low. Based on MSC. Patran for secondary development platform,were based on Marc solver,make fulluse of the powerful features of the Patran command language,by making the custom menus and graphical in-terface,can submit automatically parameterized modeling, analysis, and read the result of analysis.The alu-minum alloy thick plate residual stress analysis software system is developed.The results show that the systemcalculation results are accurate,convenient and practical,and the efficiency is improved greatly. The errorlimit is 8.5 %.
WANG Dong,XIAO Bo,SONG Zhi-dong,HE Zong-hai
Abstract: Based on the APDL( ANSYS Parametric Design Language ) of commercial finite element softwareANSYs and selecting the double-ellipsoid heat source model,the finite element model of (345B plate T-jointmulti-layer and multi-pass welding is created. With the element birth and death technology and simulating thefilling process of weld material by programming subroutine which activates the welding element step by step.The temperature field distribution regularities of the model under different welding speeds are analylized andworked out the thermal cycling curves of typical positions.The simulation results are verified through experi-ment which prove the reliability of the welding simulation and provide some theoretical help to analysis the ac-tual welding process.
YANG Mu-ye1,JI Bo-hai1,FU Zhong-qiu1,XU Han-jiang2
Abstract: Based on the 3rd Nanjig Yangtze River Bridge and the measured data of traffic,the analysis of thestress and damage prediction influencing factors of the fatigue details on welding roots in U - Rib and orthotro-pic steel bridge deck under the and the wheel load is made.Based on the cumulative damage failure criterion,fatigue damage degree calculated by nominal stress method is more reliable and notch stress is not stable whilecompare to other methods. For the steel deck plate details in this paper,FE analysis prediction of fatigue lifeshowed that 1mm hot spot stress method is of strong theory and most accuracy results. This approach is recom-mended for predicting the fatigue life of details on welding roots in U - Rib and orthotropic steel bridge decks.
YUAN Yu-qing1,LIU Feng-li1,WANG Xuan-cang1
Abstract: To explore tensile strength index of anti-cracking interlayer between old cement pavement and as-phalt overlay,based on the special model of APP modified bituminous linoleum reinforced the structure,me-chanical analysis,theoretical derivation and numerical simulation were put forward. Then,practical calcula-tion formula of tensile strength of anti-cracking layer was also deduced. Finally,strength index was recommen-ded. In the premise of small deformation,deflection value is proportional to crack width and elongation.Pul-ling force of anti-cracking sandwich is proportional to crack width and pavement pressure, and inverse to elon-gation. The anti-cracking interlayer with 1000 MPa modulus can obtain the best economic technology effect,when the maximum principal stress,equivalent stress and maximum shear stress are 0.59,1.02 and 0. 51MPa,respectively. In consideration of the general test methods and expression,the tensile strength of APP li-noleum should be not less than 300 N/50 mm.
Ll Jie,CHEN Huai,WANG Yan,CHEN Dai-hai
Abstract: In view of the problem of the bridge deck ’s large deformation of a curved chord concrete filled steeltubular truss bridge,which is overpass over an electrified main line,bridge analytic software is firstly used tobuilt finite model to analyze the old structure. In combination with static test results,the reason of the bridgedeck ’s large deformation is discussed. Then in line with some principles of little effect below the railway oper-iou,coIILcL0u sate au easlIe,savng uvesuen,au euecuvey upovg ue unuge opetauou stae,the transformation plan is put forward. These plans are structure system transformation,strengthening trans-verse support and tension sling. The transformation steps are given too. Finally,the effect of transformation isanalyzed and evaluated. Through analysis,it shows that structure after transformation is safety and the deform-ation of the bridge deck and the cross beam is greatly reduced. The effect of transformation is significant.
WANG Yi-ming1,2,YANG Jun-sheng1,LUO Lu-sen3,LIN Hui1
Abstract: Based on the statistical analysis of water pressure load on tunnel lining,the main influencing factorsof water pressure are analyzed. The main control ingredients are geological structure,rock permeability,thesupply and drainage of Karst water,vertical zonation of Karst water. The population distribution characteristicsof water pressure on liner are also studied with different drainaged designs. A large number of drainage leadsto a small water pressure on lining. When full-sealing water proofing lining is employed,the water pressure onlining is equal to hydrostatic pressure. When Karst water is released,the water pressure can be reduced sharp-ly. The water pressure on lining can be weakened by controlled drainage design.Based on the statistics of datameasured in field,a fuzzy synthetic evaluation system of water pressure is established. According to the evalu-ation results of water pressure,reasonable choice of different drainage patterns can be acquired.
LV Peng-min,YANG Long-fei,WANG Bin-hua
Abstract: The MSS50-38000 overhead launching gantry is taken as research object. The body ’s strength andstiffness under the maximum amount of pouring condition are analyzed with the software ANSYS,the stress dis-tribution and deflection curves of the overhead launching gantry are obtained. Based on the finite element cal-culations,the 1l high stress points of structure were monitored throughout the pouring process, and the testingresults are consistent with the theoretical calculations. The results of this paper will provide some references forthe design and safe construction of the overhead launching gantry.
WANG Jun1,2,KONG Ya-mei1,LIU Li-xin2
Abstract: Precisely predicting the long term deflection is one of the most important advantages of prestressedconcrete beam with pretensioned bent-up tendons. By loading three prestressed concrete beams with preten-sioned bent-up tendons in a long term,the mid-span deflection and section creep strain were studied. Togetherwith the numerical relationship expression between creep coefficient and creep deflection coefficient which wasestablished earlier,the numerical relationships among creep coefficient,long-term deflection coefficient,andcreep deflection coefficient were further studied. The results show that: The value of the long-term deflectioncoefficient is 1.1 times that of the creep coefficient. Finally,a practical expression was derived for calculatingthe long-term deflection of prestressed concrete beam with pretensioned bent-up tendons,which took a numberof influencing factors into consideration ,such as concrete shrinkage,concrete creep,partially prestressed rati-os,the axial compression and the moment value due to prestressing,component equivalent sectional area andthe section modulus of bending,etc. .
JIA Shan-po1,2,LIN Jian-pin2,LlU Tuan-hui2,CUI Li-hua2,TANG Xiao-qi2,JIANG Su-ping2
Abstract: Further study of the mechanism and law of rock deformation and breakage under the temperatureeffect has great significance to the safety and stability of the underground rock engineering. Based on the evo-lution characteristics of rock mechanics parameters under the temperature effect,a new thermo-elasto-plasticconstitutive model with improved Mohr-Coulomb criterion is presented,which can depict the temperature effectand softening behaviours of the rock. The main contents of the implicit constitutive integration algorithm arediscussed systematically; and the consistent stiffness matrix is deduced. Based on the implicit Euler stress in-tegration algorithm,the UMAT subroutine of the model is developed in ABAQUS. The numerical simulationunder various stress states and temperatures shows that the numerical simulations agree with the experimentalrules and the proposed model is able to depict effectively the main features of brittle-plastic transition of rock.
SUN Li-ping1,WANG Xin-ling2, ZOU Xu-yan3 ,QIAN Hui2
Abstract: Based on the previous work of the horizontal low cyclic test study on RC frame and RC frame rein-forced with CFRP sheets,the Pushover analysis about these tests is carried out by using the FEA softwareSAP2000,and the analysis result shows a good consistency with the test result. On this basis,the FEA modelof the damaged RC frame reinforced with CFRP sheets is established,where the damage degree of RC framecan be expressed by defining the material modulus.Then,the Pushover analysis is carried out to study theseismic performance of the RC frame strengthened with CFRP sheet. The results show that the ductility andbear capacity of the frame will decrease with the increment of the damage degree. The feasibility and the ra-tionality of the proposed analysis method are verified in this paper.
LV Peng-min,SONG Nian-b,Ll Da-tao
Abstract: In order to study the fatigue characteristics on the diaphragm arc transition for orthotropic bridgedeck,Jiujiang Yangtze River bridge was taken as an example,and the fatigue test specimens of the diaphragmand U rib local structural detail were made.Experimental results showed that 8 samples fatigue crack occurredin the diaphragm with U rib welds in 13 samples,and 5 samples fatigue crack occurred in the diaphragm aretransitional area,which illustrated that the diaphragm arc transitional area is one of the dangerous places of thefatigue failure. Finite element analysis and stress tests all indicated that this region is in the compressive stressstate,but the shear stress is very large,and the fatigue failure belongs to shear fatigue failure.Comparing theexperimental data with European standard Eurocode3,we can find it meets the T -N curve equation of the al-lowable shear stress amplitude for 100 MPa. The results of this study can provide reference for the strength de-sign and life assessment on the orthotropic deck structure details.
CHEN Yuan-hong
Abstract: High speed railway is strict with the requirements for deformation,for the subgrade abnormal settle-ment on one high-speed railway station,through the verification of design and construction quality and the analy-sis of subgrade settlement caused by the regional structure and the exploitation of groundwater,and the founda-tion pit dewatering of surounding buildings,it has been found out that the reason which has caused the the sub-grade foundation settlement is the foundation pit dewatering of station square,the influence scope of foundationpit pumping has been analysized and determined. Therefore,the efficient solution has been adopted,Thesmoothness of track has been satisfied by fitting and adjusting the vertical section of railway line,the foundationpit dewatering of station square has been immediately called of,the foundation pit dewatering of subsequentconstruction has been controlled and limited,monitoring has shown that the subgrade settlement of has been con-trolled rapidly and effectively,it has been ensured that high speed railway operates safely and stablely.
LI Wei-ying
Abstract: Based on the systematic study of the planning concept of modern academy campus which combinedthe native historic cultural resources and the purpose of Guoxue education,this paper proposes the conceptthat planning and design style of “modern academy”should reflect the age of “traditional academy”and em-body the historic“ academy spirit”naturally. This paper evaluated the planning concept of Songyang Acade-my,Zhengzhou University and indicated the positive influence of this case on the similar projects about historyand culture.
ZHAO Jun1,2,SHEN Ming-wei3,ZHU Dai-yin1,ZHAO Jian-yang4
Abstract: The clutter distribution of airborne bistatic radar varie with ranges due to the relative motion be-tween the transmiter and the receiver and the covariance matrix estimation is no longer accuate ,so that the sta-tistical STAP methods degrade. In this paper,a new clutter compensation algorithm for airborne bistatic radar is proposeu. This methou involves frist a pre-processing with Doppler warping methou to bring the clutter spectra together in the deriction of main beam and subquently Doppler compensation of different range gates in thedirection of multiple space angels.Simulation results show the proposed method can reduce the clutter nonho-mogeneity of bistatic radar effectively and is spuerior to the traditional compensation methods.
WANG Zhong-yong1,JIA Meng1,HOU Zhong-xin2,CHEN Zai-xu2
Abstract: For the task of segmentation and counting of granular objects with low quality images,a new meth-od which based on watershed and morphology is presented. First ,an oversegmented result is gotten by conduc-ting the watershed algorithm to the smoothed image. Then the region merge stage,which is directed by usingthe morphological features defined in this article,as well as weighted Mahalanobis distance and region adja-cency graph (RAG),takes place.Experiments with real images demonstrate the validity of the method,thatit is invariant under translation of gray scale,contrast and noise. And it performs better than any present meth-od ,in terms of precision-recall criterion.
YAN Xin-fang,WANG Xiao-xiao,FENG Yan,YAN Jing-jing
Abstract: To prolong the lifetime of wireless sensor network,a Clustering Topology Algorithm Based on Q-learning in WSN ( CTQL)is proposed on the basis of classical clustering algorithms such as ETBG. The Or-dered Weighted Average ( OWA) operator multi-attribute decision making method is used to determine theweight of the nodes, and Q learning algorithm is used to periodically train the cluster heads.So the Q value ofthe optimal path is selected of this algorithm and the topology control is realized. Through simulation studyshows that the use of Q-learning algorithm to resolve the problem that much energy consumption of ETBG algo-rithm fails to find the best path and CTQL effectively extend the network lifetime.
MA Li,WANG Zhen-xue,YE Hui-ying,ZHU Jun-yao
Abstract: Conductor surface electric field strength is the determining factor for radio interference,audiblenoise and corona loss of ultra-high voltage direct current(UHVDC)transmission line,so it is particularly im-portant to accurately calculate the conductor surface electric field strength. The study of factors on the surfaceelectric field at home and abroad is more less. Therefore the investigation is carried out on the influence of sub-conductor number,sub-conductor cross section,split spacing and conductor height on the conductor sur-face maximum field strength,which used charge simulation method by set 12 charge simulation in each sub-conductor. The program is written in MATLAB language to calculate and simulate,and each variable affectingon surface electric field strength is resulted quantitatively,which provides an important theoretical basis for en-gineering construction how to select the structural parameters of conductor.
ZHANG Yong,DANG Lan-xue
Abstract: To solve the problem that the features extracted by randomfaces method have weak discriminative a-bility in sparse representation-based classification ( SRC),a sparse representation - based face recognitionmethod by linear discriminant analysis ( LDA) feature extraction was proposed. Firstly,LDA is used to solvethe optimal discriminative projective subspace,and then the training samples are projected onto the subspaceto extract the features of the training samples. Using the features of the trainings samples as the dictionary, thefeatures of the test sample can be sparsely represent as linear combination of the atoms of the dictionary. Fur-thermore,using the sparse coefficients associated with the special class,this method approximates the featuresof the test sample and calculates the reconstruction error between the features of the test sample with its ap-proximation associated with the special class. Based on the reconstruction error associated with special class,the test sample can be classified accurately. Experimental results on Extend Yale B and CMU PIE face data-bases show that face recognition method proposed in this paper has a good performance.
LIAO Ping,YU Wei-xing,LIU Chun-liang,Ll Yu,ZHENG You-juan
Abstract: For the realization of intelligent demand of the lifting part of the hydraulic static pile driver,a designabout a set of safety monitoring system based on SPV210 processor and embedded Linux operating system isproposed in the paper.To achieve the function of graphics,sound and light alarm,the system monitors the re-al-time status of various conditions by multi-sensor installed on the static pile driver lifting parts. We recordthe running and lifting operation information via the Linux operating system,which is similar to the black box.The experiment results demonstrate that the system can effectively prevent the overload problem and achievethe monitor protection function.
AN Xiao-wei1,SU Hong-sheng1,2
Abstract: Group Search Optimization (GSO) is a swarm intelligence approach inspired by animal searchingbehavior and group living theory. It is simple and efficient , and easy to implement. The searching mode of thescrounger is oversimplified , so it falls into local optimum easily. In order to enhance its convergence speed andprecision,the improved Group Search Optimization ( IGS0) is proposed. Inheriting the strategy of producer-scrounger of GSO,IGSO introduces the strategy of the Antificial Fish Swarm (AFS) algorithm to the behaviorof the scrounger. By introducing prey , fellow , swarm and leap of the AFS algorithm , searching forms is diver-sified,as well as the best individuals of group and best groups of population can be considered,IGS0 can ef-ectively avoid the local optimum. Six benchmark functions are used to evaluate the performance of two algo-rithms..Experimental results.show that ICSO.is able to achieve better results than standard GSo.
DING Guo-qiang1,MA Jun-xia3,XIONG Ming1,Qiao Xiang-wei1
Abstract: Proceeding from actual technological needs of the inertial navigation system ’s initial alignmenttechnology of warship shipboards,specific to rigidity shipboards,this paper analyzed the affect expressions ofLever-arm effect of transfer alignment process in strap-down inertial navigation system ’s velocity and accelera-tion ( ecificforce ) with the effect of lever-arm error vector,and in the situation of large initial misalignment an-gles,and with the conceptions of the nominal misalignment angle and calculated angle developed the velocityand attitudes matching transfer alignment model algorithm with large misalignment attitudes of SINS’otherthan traditional models,and carried out the system states and parameters estimation performance research.Thesimulated results indicate that the model algorithm performance,with comparison studying inhering lever-armvector error’s influence on SINS misalignment attitudes’estimation error and its alignment accuracy,and withdifferent initial lever-arm vectors their effects on misalignment attitudes’estimation error and its accuracy,andverified the model algorithm’s validity and its superior alignment accuracy,and the research results are of greattheory and application value in design of SINS.
CHEN Hong-bing,MIN Jing-yan
Abstract: There were detecting errors by a grid frequency ’s varying and not enough to lock phase free degreefor a single phase grid. In view of the above mentioned difficulties,the single phase phase-locked loop ( SP-PLL.) based on a self-adaptive frequency filter (SFF) was researched. Firstly,performances and self-adaptivelaw of the SFF were analyzed,and then the key parameters of the phase-locked loop were tuned to get the opti-mum performance. Finally,the researched phase-locked loop was simulated and investigated. Research resultshave proved the single phase phase-locked loop base on a SFF can precisely detect the phase and the frequen-cy of a single phase grid,and the error of detecting phase brought by the frequency varying has been elimina-ted. The correctness and the feasibility of the proposed phase-locked loop were verified through the simulateresults in the distorted grid and the frequency varying grid.
CHEN Jun-ying1,FENG Xiang-ying1,2,SHI Zhao-xia’1,3,FANG Shu-qi1,HAN Xiu-li1, WANG Duo1
Abstract: The activated carbon was prepared from desilicon rice husk by compound activating agents ( NaOHand Na,CO,). The influence of four factors ( activation temperature,activation time,mixed ratio,mass con-centration of the impregnating solution) and three levels w investigated. The process was optimized by re-sponse surface methodology. The results showed that activation temperature and concentration of the impregna-ting solution were important factors on iodine adsorption value of activated carbon. The best conditions of pre-paring activated carbon the activation temperature of 635℃,activation time of 35 min,the mixing ratio of 4 :l,mass concentration of the impregnating solution of 40%.The iodine adsorption value was 1383.5 mg/g,which was consistent with the predicted values. The structure and morphology of samples characterized bySEM. The specific surface area and pore-size distribution calculated by the methods of BET and BJH, respec-tively. The activated rice husk carbon exhibit a high specific surface area of 1566.1m /g,average pore diam-eter of 2. 05 nm ,total pore volume of 0.80 cm’/ g.
LIU Qi-jia1,ZHANG Li-qi2.FENG Qi1
Abstract: In this paper,we study the online scheduling on a single machine with deteriorating jobs and deliv-ery times.The objective function is to minimize the maximum delivery completion time of these jobs. For thisonline scheduling problem,the objective is to design an effective online algorithm. We establish a lower boundby adversary strategy, i.e,design a bad instance to make the ratio of the objective by online algorithm andoffine objective as big as possible,then we present an online algorithm by this lower bound. Thus we get alower bound by adversary strategy and an online algorithm with the competitive ratio of 2.
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