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RSS2014 Vol. 33, No. 10
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2014, 33(10): 1445-1449.
doi: 10.13433/j.cnki.1003-8728.2014.1001
PDF 672KB
Abstract:
Rotors vibration signal of rotating machinery often contains various harmonic and high frequency doublingin addition to base frequency by using amplitude spectrum, power spectrum and other traditional spectral analysismethods.Factors that cause 2X frequency doubling of rotor vibration signal may be misalignment, cracks, electromagnetic interference, etc, and it is difficult to determine the nature and causes of 2X frequency doublingvibration components directly from the amplitude spectrum and other traditional spectral analyses.A variety of rotorsystem failures are simulated based on the rotor test rig, this work mainly studies the application of 2D-holospectrumand shaft orbits in shaft crack fault and rubbing fault diagnosis of rotating machinery, the results verifys theeffectiveness of the proposed algorithms.
Rotors vibration signal of rotating machinery often contains various harmonic and high frequency doublingin addition to base frequency by using amplitude spectrum, power spectrum and other traditional spectral analysismethods.Factors that cause 2X frequency doubling of rotor vibration signal may be misalignment, cracks, electromagnetic interference, etc, and it is difficult to determine the nature and causes of 2X frequency doublingvibration components directly from the amplitude spectrum and other traditional spectral analyses.A variety of rotorsystem failures are simulated based on the rotor test rig, this work mainly studies the application of 2D-holospectrumand shaft orbits in shaft crack fault and rubbing fault diagnosis of rotating machinery, the results verifys theeffectiveness of the proposed algorithms.
2014, 33(10): 1450-1454.
doi: 10.13433/j.cnki.1003-8728.2014.1002
Abstract:
In order to seek a convenient method to modeling the dual-rotor system and reduce the dimensions, applications of the fixed interface modal synthesis method and the finite element software ANSYS on dual-rotor systemmodeling are studied.Motion equation is established with mass matrix and stiffness matrix obtained from ANSYS.Then the dimensions are reduced by the fixed interface modal synthesis method.Correctness of the system parametersis verified by the characteristics of modal mass matrix and modal stiffness matrix.Critical speed characteristics arecalculated, the results of which are verified with that of ANSYS(finite element method).Besides, the modal cut-offfrequency's effect on critical speed is analyzed.The transient analysis of the uniformly changed velocity process iscarried out and verified by experiments.The research shows that: modeling method in this paper is correct andreliable, and can be easily used to calculate the response characteristics of the dual-rotor system.
In order to seek a convenient method to modeling the dual-rotor system and reduce the dimensions, applications of the fixed interface modal synthesis method and the finite element software ANSYS on dual-rotor systemmodeling are studied.Motion equation is established with mass matrix and stiffness matrix obtained from ANSYS.Then the dimensions are reduced by the fixed interface modal synthesis method.Correctness of the system parametersis verified by the characteristics of modal mass matrix and modal stiffness matrix.Critical speed characteristics arecalculated, the results of which are verified with that of ANSYS(finite element method).Besides, the modal cut-offfrequency's effect on critical speed is analyzed.The transient analysis of the uniformly changed velocity process iscarried out and verified by experiments.The research shows that: modeling method in this paper is correct andreliable, and can be easily used to calculate the response characteristics of the dual-rotor system.
2014, 33(10): 1455-1458.
doi: 10.13433/j.cnki.1003-8728.2014.1003
Abstract:
Aim at removing the residual liquid within the barrel-yarn efficiently in yarns modification and dyeing, akind of rotating cage was designed for using in the high-speed and large-inertia environment and it was checked withthe shearing force and bending moment.Then the structure of rotating cage was improved according to the results ofanalysis based on the materials mechanics.Then, Simulations were conducted for the original and improvedstructures of rotating cage by using the finite-element analysis software, respectively.The results show that thedeformation of the rotating cage is effectively controlled and the maximum stress has a substantial reduction and thefatigue safety coefficient is also increased for the improved rotating cage.The present studies provide theoreticalreference for the structural design of the work condition of the high speed and large inertia rotating cage for removalof liquid in barrel-yarn.
Aim at removing the residual liquid within the barrel-yarn efficiently in yarns modification and dyeing, akind of rotating cage was designed for using in the high-speed and large-inertia environment and it was checked withthe shearing force and bending moment.Then the structure of rotating cage was improved according to the results ofanalysis based on the materials mechanics.Then, Simulations were conducted for the original and improvedstructures of rotating cage by using the finite-element analysis software, respectively.The results show that thedeformation of the rotating cage is effectively controlled and the maximum stress has a substantial reduction and thefatigue safety coefficient is also increased for the improved rotating cage.The present studies provide theoreticalreference for the structural design of the work condition of the high speed and large inertia rotating cage for removalof liquid in barrel-yarn.
2014, 33(10): 1459-1462.
doi: 10.13433/j.cnki.1003-8728.2014.1004
Abstract:
According to the Oil Tank Cleaning Robot characteristics, and the merit and demerit of presentworkspace solving methods, respectively using Diagrammatize method and Monte Carlo Method and Simulationmethod solved the workspace of Oil Tank Cleaning Robot.And the different views was compared among the threemethods.The result indicated that different methods had different suit conditions in solving robot workspace and theconsequences were also different.On the basis of that result selected the prior method of solving Oil Tank CleaningRobot workspace on different occasions.The topic provides theory basis for structure optimization and obstacleavoiding and motion controlling.
According to the Oil Tank Cleaning Robot characteristics, and the merit and demerit of presentworkspace solving methods, respectively using Diagrammatize method and Monte Carlo Method and Simulationmethod solved the workspace of Oil Tank Cleaning Robot.And the different views was compared among the threemethods.The result indicated that different methods had different suit conditions in solving robot workspace and theconsequences were also different.On the basis of that result selected the prior method of solving Oil Tank CleaningRobot workspace on different occasions.The topic provides theory basis for structure optimization and obstacleavoiding and motion controlling.
2014, 33(10): 1463-1467.
doi: 10.13433/j.cnki.1003-8728.2014.1005
Abstract:
Nanoimprint lithography (NIL) has been developed fast in decades.Vibration caused by novelCompressional Gas Cushion Press (CGCP) style of NIL deteriorates the pattern transfer precision of CGCP.Damping vibration system is used to reduce the influence of vibration caused by servomotor and piston＇s movement.Damping vibration model is established based on vibration source and CGCP-NIL structure.Analysis of materialproperties and finite element modeling simulation optimizes materials performance and the inner structure ofdamping vibration system.The simulation results indicate that circumcircle radius of honeycomb in the optimal unitlayer is 0.02 m and the circumcircles of two adjacent honeycombs are external tangent.The honeycomb dampingvibration cushion with three optimal unit layers which are made up of rubber can attenuate 87.51% of the maximumamplitude.Damping vibration system can lower the vibration source impact on fidelity.
Nanoimprint lithography (NIL) has been developed fast in decades.Vibration caused by novelCompressional Gas Cushion Press (CGCP) style of NIL deteriorates the pattern transfer precision of CGCP.Damping vibration system is used to reduce the influence of vibration caused by servomotor and piston＇s movement.Damping vibration model is established based on vibration source and CGCP-NIL structure.Analysis of materialproperties and finite element modeling simulation optimizes materials performance and the inner structure ofdamping vibration system.The simulation results indicate that circumcircle radius of honeycomb in the optimal unitlayer is 0.02 m and the circumcircles of two adjacent honeycombs are external tangent.The honeycomb dampingvibration cushion with three optimal unit layers which are made up of rubber can attenuate 87.51% of the maximumamplitude.Damping vibration system can lower the vibration source impact on fidelity.
2014, 33(10): 1468-1472.
doi: 10.13433/j.cnki.1003-8728.2014.1006
Abstract:
Aiming to predict the barrel life, the theoretical(empirical) formula or the modeling method based onthe degradation data are generally adopted, but the prediction accuracy is not enough.In order to reduce theconfidence interval of predicted life, a data fusion model is obtained by combining the simulation of degradationprocess with the measured data of performance degradation.Considering a caliber weapon barrel as the researchobject, based on the stochastic finite element method, combined with barrel melting ablation prediction model, thedistribution rule of barrel inner surface radial wearing is obtained and converted to theoretical simulation degradationmodel which is based on the theory muzzle velocity.Then combining with a small sample barrel test data, theparameter of the model is updated by using the Bayes statistics.Finally, the various methods of the life predictionresults and the confidence interval are compared, and the effectiveness of the present method is verified.
Aiming to predict the barrel life, the theoretical(empirical) formula or the modeling method based onthe degradation data are generally adopted, but the prediction accuracy is not enough.In order to reduce theconfidence interval of predicted life, a data fusion model is obtained by combining the simulation of degradationprocess with the measured data of performance degradation.Considering a caliber weapon barrel as the researchobject, based on the stochastic finite element method, combined with barrel melting ablation prediction model, thedistribution rule of barrel inner surface radial wearing is obtained and converted to theoretical simulation degradationmodel which is based on the theory muzzle velocity.Then combining with a small sample barrel test data, theparameter of the model is updated by using the Bayes statistics.Finally, the various methods of the life predictionresults and the confidence interval are compared, and the effectiveness of the present method is verified.
2014, 33(10): 1473-1478.
doi: 10.13433/j.cnki.1003-8728.2014.1007
Abstract:
A 3D flow field model of small wind turbine blade is established and the flow behavior and aerodynamiccharacteristics of wind turbine under the different wind speeds are analyzed by using fluid mechanics softwareFLUENT.The results show that: the blade stall phenomenon as the wind speed increases is becoming more serious, the maximal value of pressure and flow rate all occur in the blade tip.With the wind speed increasing, the outputpower rises, but both tip speed ratio and wind energy utilization coefficient reduce.Experiment test is also done forthe wind turbine through wind energy experiment platform, and the experiment data is compared with the simulationresult, they agree well with each other.
A 3D flow field model of small wind turbine blade is established and the flow behavior and aerodynamiccharacteristics of wind turbine under the different wind speeds are analyzed by using fluid mechanics softwareFLUENT.The results show that: the blade stall phenomenon as the wind speed increases is becoming more serious, the maximal value of pressure and flow rate all occur in the blade tip.With the wind speed increasing, the outputpower rises, but both tip speed ratio and wind energy utilization coefficient reduce.Experiment test is also done forthe wind turbine through wind energy experiment platform, and the experiment data is compared with the simulationresult, they agree well with each other.
2014, 33(10): 1479-1483.
doi: 10.13433/j.cnki.1003-8728.2014.1008
Abstract:
The approach to filling holes from 3D point clouds measured by 3D scanner was studied to get accurateand complete 3D point clouds of several excavator bucket teeth.RBF neural network algorithm was successfullyapplied in mending the data deletion serious regional and cross-facial data deletion area from those 3D incompletepoint clouds which are difficult to fill well by well-know commercial reverse software.The results of comparisonshow that the mending effects by using RBF neural network algorithm are better than by using the reverse software, and RBF neural network algorithm has good effects on solving the problems of mending the 3D incomplete pointclouds of the complicated bucket teeth.Several complete point clouds of different bucket teeth were obtained.Theresults of mending provided a reliable references for obtaining design data by using the“point cloud-surface-solidmodel” converse countermeasure.the main processing and key links for the hole filling were described briefly.
The approach to filling holes from 3D point clouds measured by 3D scanner was studied to get accurateand complete 3D point clouds of several excavator bucket teeth.RBF neural network algorithm was successfullyapplied in mending the data deletion serious regional and cross-facial data deletion area from those 3D incompletepoint clouds which are difficult to fill well by well-know commercial reverse software.The results of comparisonshow that the mending effects by using RBF neural network algorithm are better than by using the reverse software, and RBF neural network algorithm has good effects on solving the problems of mending the 3D incomplete pointclouds of the complicated bucket teeth.Several complete point clouds of different bucket teeth were obtained.Theresults of mending provided a reliable references for obtaining design data by using the“point cloud-surface-solidmodel” converse countermeasure.the main processing and key links for the hole filling were described briefly.
2014, 33(10): 1484-1488.
doi: 10.13433/j.cnki.1003-8728.2014.1009
Abstract:
In order to explore vertical vibration characteristics of a longitudinal roadheader under the influence ofrandom excitations, longitudinal dynamics model of the roadheader was established according to the theory of multi-body dynamics and longitudinal differential equations of the roadheader were established by using Lagrangianequation method.Taking a domestic longitudinal roadheader as an example, for the cutting head suffers randomexcitations, the mathematical models of vertical vibration responses were derived using the pseudo-excitation methodand the responses characteristics of cutting head, boom and body were obtained by applying MATLAB programs.The results show: natural frequency of cutting head, boom and body locates in 3.2 Hz, 2.9 Hz, 2.3 Hz; with theincrease of the stiffness and the damping between the boom and the body, the peak of the PSDS of displacement ofcutting head and body gradually decreases, longitudinal vibration can be decreased by increasing the stiffness andthe damping between boom and body, the body and the base.A multi-body dynamics model was simulated inAdams for the sake of identifying the conclusions.The theoretical value, the model simulation results and theexperiments are relatively close, which imply reliability of this method.
In order to explore vertical vibration characteristics of a longitudinal roadheader under the influence ofrandom excitations, longitudinal dynamics model of the roadheader was established according to the theory of multi-body dynamics and longitudinal differential equations of the roadheader were established by using Lagrangianequation method.Taking a domestic longitudinal roadheader as an example, for the cutting head suffers randomexcitations, the mathematical models of vertical vibration responses were derived using the pseudo-excitation methodand the responses characteristics of cutting head, boom and body were obtained by applying MATLAB programs.The results show: natural frequency of cutting head, boom and body locates in 3.2 Hz, 2.9 Hz, 2.3 Hz; with theincrease of the stiffness and the damping between the boom and the body, the peak of the PSDS of displacement ofcutting head and body gradually decreases, longitudinal vibration can be decreased by increasing the stiffness andthe damping between boom and body, the body and the base.A multi-body dynamics model was simulated inAdams for the sake of identifying the conclusions.The theoretical value, the model simulation results and theexperiments are relatively close, which imply reliability of this method.
2014, 33(10): 1489-1494.
doi: 10.13433/j.cnki.1003-8728.2014.1010
Abstract:
To complete the entire job on schedule and reduce manufacture cost, a mathematical model for taskallocation of manufacturing system was established in this paper.Aiming at the shortages exiting in traditionalcoordination mechanism for solving task allocation, a hormone-based implicit coordination approach is proposed byreferring to hormone-regulation principles in the biological body.Compared with the traditional CNP coordinationmechanism, this approach is characterized by higher efficiency, lower communication and better robustness.
To complete the entire job on schedule and reduce manufacture cost, a mathematical model for taskallocation of manufacturing system was established in this paper.Aiming at the shortages exiting in traditionalcoordination mechanism for solving task allocation, a hormone-based implicit coordination approach is proposed byreferring to hormone-regulation principles in the biological body.Compared with the traditional CNP coordinationmechanism, this approach is characterized by higher efficiency, lower communication and better robustness.
2014, 33(10): 1495-1499.
doi: 10.13433/j.cnki.1003-8728.2014.1011
Abstract:
Based on the circular-non circular bevel gear differential gear train, a new type of non-circular bevelgear swing stop-step device is designed in this paper.The principle of this device is describedand the transmissionratio function of a pair of non-circular bevel gear located in the transmission center is deduced.The design andchecking method based on the theory of non-circular bevel gear is expounded.Finally a virtual prototype of thisdeviceis established and its displacement responseis obtained by using ADAMS software, The results verify thecorrectness of the proposed design method and principle.
Based on the circular-non circular bevel gear differential gear train, a new type of non-circular bevelgear swing stop-step device is designed in this paper.The principle of this device is describedand the transmissionratio function of a pair of non-circular bevel gear located in the transmission center is deduced.The design andchecking method based on the theory of non-circular bevel gear is expounded.Finally a virtual prototype of thisdeviceis established and its displacement responseis obtained by using ADAMS software, The results verify thecorrectness of the proposed design method and principle.
2014, 33(10): 1500-1504.
doi: 10.13433/j.cnki.1003-8728.2014.1012
Abstract:
Aiming at the questions of traditional flat-lapping method that high repetition rate of lapping trajectory onworkpiece center point, and velocity distribution inhomogeneous in radial, a double-side flat-lapping method ofdisplacement-rotation based on the solid abrasive lapping technology is proposed.Workpiece is driven by varietallapping force which comes from the movements of lapping tool.The motion pattern of workpiece is changed inprinciple, and the degrees of freedom in workpiece are increased.A random relative motion between workpiece andlap tool while the workpiece rotates is put into effect.The trajectory in the rotation center of both workpiece and laptool are time-variant curves.For the different lapping process, the new method overcomes the deficiencies in thecommon lapping method, and a new CNC lapping machine tool is developed on the basis of the present principle.The simulation analysis further verifies that the new method has the advantage in improving the uniformity of velocitydistribution, and the time variation in lapping trajectory.The compared experiment shows that the new lappingmethod reached lower surface roughness than that for the planet type lapping at the same processing conditions.
Aiming at the questions of traditional flat-lapping method that high repetition rate of lapping trajectory onworkpiece center point, and velocity distribution inhomogeneous in radial, a double-side flat-lapping method ofdisplacement-rotation based on the solid abrasive lapping technology is proposed.Workpiece is driven by varietallapping force which comes from the movements of lapping tool.The motion pattern of workpiece is changed inprinciple, and the degrees of freedom in workpiece are increased.A random relative motion between workpiece andlap tool while the workpiece rotates is put into effect.The trajectory in the rotation center of both workpiece and laptool are time-variant curves.For the different lapping process, the new method overcomes the deficiencies in thecommon lapping method, and a new CNC lapping machine tool is developed on the basis of the present principle.The simulation analysis further verifies that the new method has the advantage in improving the uniformity of velocitydistribution, and the time variation in lapping trajectory.The compared experiment shows that the new lappingmethod reached lower surface roughness than that for the planet type lapping at the same processing conditions.
2014, 33(10): 1505-1509.
doi: 10.13433/j.cnki.1003-8728.2014.1013
Abstract:
Aiming at difficult identification of unbalanced fault data for the mechanical equipment monitoring, anovel method based on similarity factor analysis of sliding mode control is proposed.In this method, the slidingmode control technology is introduced, and a dataset pool is constituted by analyzing the principal componentanalysis similarity factor between the target data and historical date, which is from the old monitoring dataset.Thenthe most similar data which will be used in training is obtained by analyzing the distance similarity factor of targetdata and the data from the dataset pool.The kernel principal component analysis-support vector machines method isapplied in the unbalanced data classification of fault rotor.The result shows that this method can improve theclassification decision boundary effectively, and reduce the false diagnosis caused by the unbalanced samples.
Aiming at difficult identification of unbalanced fault data for the mechanical equipment monitoring, anovel method based on similarity factor analysis of sliding mode control is proposed.In this method, the slidingmode control technology is introduced, and a dataset pool is constituted by analyzing the principal componentanalysis similarity factor between the target data and historical date, which is from the old monitoring dataset.Thenthe most similar data which will be used in training is obtained by analyzing the distance similarity factor of targetdata and the data from the dataset pool.The kernel principal component analysis-support vector machines method isapplied in the unbalanced data classification of fault rotor.The result shows that this method can improve theclassification decision boundary effectively, and reduce the false diagnosis caused by the unbalanced samples.
2014, 33(10): 1510-1513.
doi: 10.13433/j.cnki.1003-8728.2014.1014
Abstract:
As one of the new plastic forming technologies, the forming performance of the NC incremental formingis mostly focused on the largest forming angle, there is a few work about the small forming angle.For small formingangle parts, the springback and unexpected bulge are two key problems in the parts forming procedure using the NCincremental forming.The positive and negative incremental forming methods are investigated through experiments.The experimental results show that unexpected bulge in the center and warp at the edge produced in negativeincremental forming can be settled by using flat tool and annealing.The edge warp produced in positive incrementalforming can be solved by settling preloading quantity of the elevating.Both of the positive and negative incrementalforming can eventually get ideal parts.
As one of the new plastic forming technologies, the forming performance of the NC incremental formingis mostly focused on the largest forming angle, there is a few work about the small forming angle.For small formingangle parts, the springback and unexpected bulge are two key problems in the parts forming procedure using the NCincremental forming.The positive and negative incremental forming methods are investigated through experiments.The experimental results show that unexpected bulge in the center and warp at the edge produced in negativeincremental forming can be settled by using flat tool and annealing.The edge warp produced in positive incrementalforming can be solved by settling preloading quantity of the elevating.Both of the positive and negative incrementalforming can eventually get ideal parts.
2014, 33(10): 1514-1517.
doi: 10.13433/j.cnki.1003-8728.2014.1015
Abstract:
Intensity interrupted turning experiment on different hardness hardened tool steel Cr12MoV with PCBN(polycrystalline cubic boron nitride) cutting tools was investigated in this paper.Using the statistical software forrange analysis based on orthogonal design method, the impacts of the hardness of work-piece and the cuttingparameters on surface roughness were analyzed, and the optimum cutting parameters were obtained.A linearprediction model and an exponential prediction model of surface roughness were built by using multiple regressionanalysis method.Then the two models were compared.The results indicated that: the four factors that affect thesurface roughness values of the primary and secondary relationship followed by the hardness of the work-piece, cutting speed, depth of cut, feed rate; the average error of the linear prediction model was 7% at most, so thelinear model could predict surface roughness well.
Intensity interrupted turning experiment on different hardness hardened tool steel Cr12MoV with PCBN(polycrystalline cubic boron nitride) cutting tools was investigated in this paper.Using the statistical software forrange analysis based on orthogonal design method, the impacts of the hardness of work-piece and the cuttingparameters on surface roughness were analyzed, and the optimum cutting parameters were obtained.A linearprediction model and an exponential prediction model of surface roughness were built by using multiple regressionanalysis method.Then the two models were compared.The results indicated that: the four factors that affect thesurface roughness values of the primary and secondary relationship followed by the hardness of the work-piece, cutting speed, depth of cut, feed rate; the average error of the linear prediction model was 7% at most, so thelinear model could predict surface roughness well.
2014, 33(10): 1518-1524.
doi: 10.13433/j.cnki.1003-8728.2014.1016
Abstract:
A new diagnosis method for the fault classification and damage degree of rolling bearing based on empiricalmode decomposition(EMD) and kernel principal component analysis(KPCA) is proposed.Firstly, the fault signal ofrolling bearing was decomposed into several intrinsic mode functions under different characteristic scales with EMD.ThenHilbert-Huang transform was employed to calculate the statistical features and dimensionless features in both time domainand frequency domain.Secondly, KPCA based on samples was introduced to eliminate redundant features and reduce thevector dimension greatly.Thus, the KPCA feature vector was acquired, which could reflect the failure.Furthermore, theclassifier based on one-versus-one support vector machine was constructed.At last, the classification of three failuremodes and different damage degree for rolling bearing was completed.
A new diagnosis method for the fault classification and damage degree of rolling bearing based on empiricalmode decomposition(EMD) and kernel principal component analysis(KPCA) is proposed.Firstly, the fault signal ofrolling bearing was decomposed into several intrinsic mode functions under different characteristic scales with EMD.ThenHilbert-Huang transform was employed to calculate the statistical features and dimensionless features in both time domainand frequency domain.Secondly, KPCA based on samples was introduced to eliminate redundant features and reduce thevector dimension greatly.Thus, the KPCA feature vector was acquired, which could reflect the failure.Furthermore, theclassifier based on one-versus-one support vector machine was constructed.At last, the classification of three failuremodes and different damage degree for rolling bearing was completed.
2014, 33(10): 1525-1530.
doi: 10.13433/j.cnki.1003-8728.2014.1017
Abstract:
Engine oil filter paper spot atlas method is a common method to determine the pollution degree of the engineoil, but this method has a certain degree of subjectivity.Using machine recognition method to replace human judgmentcan avoid the influence of subjective factors.The engine oil pollution degree recognition system designed in this paper isbased on digital image detection theory, in which the six colors characteristic values of R, G, B, Gray, a and b areextracted from the spots atlas image.It shows that the six colors characteristic were medium to strong correlation to thedegree of contamination and the correlation was significant.A backpropagation neural network classifier recognitionsystem was established and the system can determine the degree of contamination of engine oil according to the collectedoil spots picture, and it provides the technical support for automotive replace engine oil by qualit.
Engine oil filter paper spot atlas method is a common method to determine the pollution degree of the engineoil, but this method has a certain degree of subjectivity.Using machine recognition method to replace human judgmentcan avoid the influence of subjective factors.The engine oil pollution degree recognition system designed in this paper isbased on digital image detection theory, in which the six colors characteristic values of R, G, B, Gray, a and b areextracted from the spots atlas image.It shows that the six colors characteristic were medium to strong correlation to thedegree of contamination and the correlation was significant.A backpropagation neural network classifier recognitionsystem was established and the system can determine the degree of contamination of engine oil according to the collectedoil spots picture, and it provides the technical support for automotive replace engine oil by qualit.
2014, 33(10): 1531-1535.
doi: 10.13433/j.cnki.1003-8728.2014.1018
Abstract:
In order to investigate the damage and failure behavior of multi-layer winding wire ropes, a set of fatiguewear equipment for wire ropes with multi-layer winding is developed by using the hoisting and luffing mechanism ofthe crane as prototype.The equipment is composed of the test bench, data monitoring system and electric controlsystem.It has the controllable function characteristic of linear velocity and tension of wire ropes.By using theequipment, the fatigue wear experiment of wire ropes in parallel grooved multi-layer winding is carried out.Theresults show that the equipment can actual reflects the process of damage and failure behavior of wire ropes in multi-layer winding, and the experimental data is accurate and reliable.
In order to investigate the damage and failure behavior of multi-layer winding wire ropes, a set of fatiguewear equipment for wire ropes with multi-layer winding is developed by using the hoisting and luffing mechanism ofthe crane as prototype.The equipment is composed of the test bench, data monitoring system and electric controlsystem.It has the controllable function characteristic of linear velocity and tension of wire ropes.By using theequipment, the fatigue wear experiment of wire ropes in parallel grooved multi-layer winding is carried out.Theresults show that the equipment can actual reflects the process of damage and failure behavior of wire ropes in multi-layer winding, and the experimental data is accurate and reliable.
2014, 33(10): 1536-1539.
doi: 10.13433/j.cnki.1003-8728.2014.1019
Abstract:
Based on the common types of mixer, a new kind of static mixer used for high viscous two-phase fluidwas designed.The impact of pre-mixing unit on the overall mixing effect was analyzedby using the Fluent software, and the influence of the number of mixing units and the entrance velocity of fluid on the mixing uniformity were alsostudied.The results showed that the mixing effect of mixer with pre-mixed unit was better than that without pre-mixed unit, and it also indicted that well mixing effect can be obtained with different entrance velocity when thenumber of mixing units reached 3.On this basis, according to the distribution of flow field and velocity field ofparticles, it wa explained that the disordering distribution of the velocity and streamline was the fundamental reasonfor well mixing effect.Meanwhile, the influence of viscosity on mixing effect was analyzed by simulation, the resultsshowed that the mixing uniformity of the mixer was improved along with the increasing of the viscosity of fluid, andthis mixer also had good mixing effect for low viscosity or middle viscosity fluid.
Based on the common types of mixer, a new kind of static mixer used for high viscous two-phase fluidwas designed.The impact of pre-mixing unit on the overall mixing effect was analyzedby using the Fluent software, and the influence of the number of mixing units and the entrance velocity of fluid on the mixing uniformity were alsostudied.The results showed that the mixing effect of mixer with pre-mixed unit was better than that without pre-mixed unit, and it also indicted that well mixing effect can be obtained with different entrance velocity when thenumber of mixing units reached 3.On this basis, according to the distribution of flow field and velocity field ofparticles, it wa explained that the disordering distribution of the velocity and streamline was the fundamental reasonfor well mixing effect.Meanwhile, the influence of viscosity on mixing effect was analyzed by simulation, the resultsshowed that the mixing uniformity of the mixer was improved along with the increasing of the viscosity of fluid, andthis mixer also had good mixing effect for low viscosity or middle viscosity fluid.
2014, 33(10): 1540-1544.
doi: 10.13433/j.cnki.1003-8728.2014.1020
Abstract:
The paper introduced the production process of ultra-fine powders with superheated steam-powered jetmill.According to the process requirement of the system, the control system was designed, which mainly consists ofsystem hardware structure and control scheme.In the hardware structure, S7-300 programmable logic controller(PLC) was used as the lower computer used, which communicated with the upper computer by PROFIBUS, tocollect data and control automatically, The remote monitor was realized by the upper computer with WINCCconfiguration software.In the control scheme, some key techniques such as the hold up control of jet mill, thetemperature control of high temperature bag filter, the pulse jet control of high temperature bag filter, on-site andremote control of system and fault scram were discussed in details.The temperature of filter and material level ofmill can be monitored and controlled accurately after the control system was debugged, the whole system ran stablyand reliably, the on-site and remote control of the key facilities was realized and it improved the reliability and theefficiency of ultra-fine powders by using superheated steam-powered jet mill.
The paper introduced the production process of ultra-fine powders with superheated steam-powered jetmill.According to the process requirement of the system, the control system was designed, which mainly consists ofsystem hardware structure and control scheme.In the hardware structure, S7-300 programmable logic controller(PLC) was used as the lower computer used, which communicated with the upper computer by PROFIBUS, tocollect data and control automatically, The remote monitor was realized by the upper computer with WINCCconfiguration software.In the control scheme, some key techniques such as the hold up control of jet mill, thetemperature control of high temperature bag filter, the pulse jet control of high temperature bag filter, on-site andremote control of system and fault scram were discussed in details.The temperature of filter and material level ofmill can be monitored and controlled accurately after the control system was debugged, the whole system ran stablyand reliably, the on-site and remote control of the key facilities was realized and it improved the reliability and theefficiency of ultra-fine powders by using superheated steam-powered jet mill.
2014, 33(10): 1545-1550.
doi: 10.13433/j.cnki.1003-8728.2014.1021
Abstract:
The paper proposed a new synthesized bayesianian approach for structure finite element model updatingby using parameters uncertainty estimation.It integrated stochastic models instead of the original model and markovchain Monte Carlo(MCMC)algorithm with gibbs sampling.By sensitivity analysis, sensitive parameters were used tosimulate and obtain parameters dynamic posterior statistics characteristics, and then the parameters uncertainty waseatimated.Numerical simulation indicates that the approach is effective, It evidently improves the computationalefficiency with SRSM, the method is suitable for finite element model updating of complex structure containing multi-parameters uncertainty.
The paper proposed a new synthesized bayesianian approach for structure finite element model updatingby using parameters uncertainty estimation.It integrated stochastic models instead of the original model and markovchain Monte Carlo(MCMC)algorithm with gibbs sampling.By sensitivity analysis, sensitive parameters were used tosimulate and obtain parameters dynamic posterior statistics characteristics, and then the parameters uncertainty waseatimated.Numerical simulation indicates that the approach is effective, It evidently improves the computationalefficiency with SRSM, the method is suitable for finite element model updating of complex structure containing multi-parameters uncertainty.
2014, 33(10): 1551-1554.
doi: 10.13433/j.cnki.1003-8728.2014.1022
Abstract:
A new kind of retractable fin stabilizer mechanism with embedded fin is designed.The mechanismincludes rotating fin mechanism, retractable fin mechanism, embedded fin and fixing mechanism.By using thismechanism, the rotating mechanism and the retractable mechanism can implement rocking motion and retractablemotion precisely.The configuration of a big fin wraping a small fin is adopted to reduce the opening size of shipbody.A fixing mechanism, installed on the surface of the fin stabilizer, is designed in order to keep fin in the rightplace when it works properly.The working process of fin stabilizer mechanism is simulated kinematicly usingPro/E, the results show that the required motion of fin stabilizer mechanism can be achieved accurately.Comparedwith integral fin, the embedded fin can reduce the opening size of ship body by about 1/5.
A new kind of retractable fin stabilizer mechanism with embedded fin is designed.The mechanismincludes rotating fin mechanism, retractable fin mechanism, embedded fin and fixing mechanism.By using thismechanism, the rotating mechanism and the retractable mechanism can implement rocking motion and retractablemotion precisely.The configuration of a big fin wraping a small fin is adopted to reduce the opening size of shipbody.A fixing mechanism, installed on the surface of the fin stabilizer, is designed in order to keep fin in the rightplace when it works properly.The working process of fin stabilizer mechanism is simulated kinematicly usingPro/E, the results show that the required motion of fin stabilizer mechanism can be achieved accurately.Comparedwith integral fin, the embedded fin can reduce the opening size of ship body by about 1/5.
2014, 33(10): 1555-1561.
doi: 10.13433/j.cnki.1003-8728.2014.1023
Abstract:
To take an SUV frame as research subject, the finite element model was established, the bending, torsional stiffness and modal were analyzed, and the modal value with the testing vale was compared in order toensure the model' effectiveness.Using the orthogonal test method to determine the lightweight components, and thesteel material for SUV frame was replaced by aluminum alloy so as to get the steel-aluminum composite lightweightframe.Then compromise programming multi-objective morphology optimization design method was adopted toimprove the stiffness and modal property.The results showed that the new frame mass reduced about 6.7 kgaltogether after using the orthogonal test and morphology optimization, meanwhile the stiffness and modal propertywas enhanced.
To take an SUV frame as research subject, the finite element model was established, the bending, torsional stiffness and modal were analyzed, and the modal value with the testing vale was compared in order toensure the model' effectiveness.Using the orthogonal test method to determine the lightweight components, and thesteel material for SUV frame was replaced by aluminum alloy so as to get the steel-aluminum composite lightweightframe.Then compromise programming multi-objective morphology optimization design method was adopted toimprove the stiffness and modal property.The results showed that the new frame mass reduced about 6.7 kgaltogether after using the orthogonal test and morphology optimization, meanwhile the stiffness and modal propertywas enhanced.
2014, 33(10): 1562-1567.
doi: 10.13433/j.cnki.1003-8728.2014.1024
Abstract:
A new multi-function vehicle for disaster rescue is presented.The main purpose is to use this new typedvehicle for disaster rescue of the scene where the natural earthquakes, mudslides, landslides and other naturaldisasters break out, not only that, this novelty vehicle also can be used for large-scale building demolition work.The vehicle for Disaster Rescue is consisted of moving system, dual turntable system, arm system, anti-interferencesystem, gravity of regulate and control system, power-monitoring system, wire-less remote control system andcomputer control system.It can be controlled by semi-autonomous and the operator tele-operating.Also it has thefunctions of autonomous obstacle avoidance, semi-automatic and automatic of gravity regulation, pivot around, semi-autonomous power management and efficient snatch, cut and rake.The moving system is constituted by themain power movement and the auxiliary movement containing the front and rear sections a total of four crawlers.Theanti-interference system utilizes two methods, control program as well as positive movement and inverse kinematicsalgorithm, to achieve the purpose of avoiding interference.The system not only can prevent the anti-interferencebetween the five joints of left arm and four joints of right arm, also can guard against the interference between dual-arms and disaster scene.The experiments showed that the scene consists of steels, pre-cast panels, stones, dirt andother substances could be cleaned up quickly.The rescue efficiency is at last 10 times than the artificial.Throughthe test for movement of the vehicle of speed, gripping force, shear force and gravity control, it indicates that theflexibility of the rescue vehicle, the stability of the gravity, the strong ability of anti-interference, the reliablecontrol and the rescue efficiency.
A new multi-function vehicle for disaster rescue is presented.The main purpose is to use this new typedvehicle for disaster rescue of the scene where the natural earthquakes, mudslides, landslides and other naturaldisasters break out, not only that, this novelty vehicle also can be used for large-scale building demolition work.The vehicle for Disaster Rescue is consisted of moving system, dual turntable system, arm system, anti-interferencesystem, gravity of regulate and control system, power-monitoring system, wire-less remote control system andcomputer control system.It can be controlled by semi-autonomous and the operator tele-operating.Also it has thefunctions of autonomous obstacle avoidance, semi-automatic and automatic of gravity regulation, pivot around, semi-autonomous power management and efficient snatch, cut and rake.The moving system is constituted by themain power movement and the auxiliary movement containing the front and rear sections a total of four crawlers.Theanti-interference system utilizes two methods, control program as well as positive movement and inverse kinematicsalgorithm, to achieve the purpose of avoiding interference.The system not only can prevent the anti-interferencebetween the five joints of left arm and four joints of right arm, also can guard against the interference between dual-arms and disaster scene.The experiments showed that the scene consists of steels, pre-cast panels, stones, dirt andother substances could be cleaned up quickly.The rescue efficiency is at last 10 times than the artificial.Throughthe test for movement of the vehicle of speed, gripping force, shear force and gravity control, it indicates that theflexibility of the rescue vehicle, the stability of the gravity, the strong ability of anti-interference, the reliablecontrol and the rescue efficiency.
2014, 33(10): 1568-1573.
doi: 10.13433/j.cnki.1003-8728.2014.1025
Abstract:
To solve the problems of large torque ripples and improve the tracking accuracy of speed regulator inconventional direct torque control system, this paper proposed a design scheme of double fuzzy direct torque controlsystem for an electric motor vehicle based on the STM32.The scheme uses a fuzzy controller instead of flux linkageand torque hysteresis comparator and speed PI regulator, in which the STM32 is the core control device.A fulldigital electric vehicle induction motor direct torque control experiment system is established.The simulationexperiments are conducted to evaluate the motor performance, where some influence factors such as the runningenvironment and mechanical drive interference are considered.The experimental results show that the system caneffectively reduce torque and flux ripple, enhance the robustness and adaptability of the system, and improve thedynamic and static qualities of the system.
To solve the problems of large torque ripples and improve the tracking accuracy of speed regulator inconventional direct torque control system, this paper proposed a design scheme of double fuzzy direct torque controlsystem for an electric motor vehicle based on the STM32.The scheme uses a fuzzy controller instead of flux linkageand torque hysteresis comparator and speed PI regulator, in which the STM32 is the core control device.A fulldigital electric vehicle induction motor direct torque control experiment system is established.The simulationexperiments are conducted to evaluate the motor performance, where some influence factors such as the runningenvironment and mechanical drive interference are considered.The experimental results show that the system caneffectively reduce torque and flux ripple, enhance the robustness and adaptability of the system, and improve thedynamic and static qualities of the system.
2014, 33(10): 1574-1578.
doi: 10.13433/j.cnki.1003-8728.2014.1026
Abstract:
The mechanical performance of self-piercing riveted (SPR) joint in aluminum and copper alloy (Al-Cu)sheets with different piercing directions is investigated experimentally, and the material properties are tested.Theformability of SPR Cu-Cu joint is analyzed by riveting experiment and finite element analysis.The mechanicalperformances of SPR joints in Al-Cu with different piercing directions are tested, and the load-displacement curves areobtained.The result show that the tensile-shear strength of SPR joint is higher than its peel strength.The strength of Cu-Cu joint is the highest, Cu-Al joint is the secondary and the Al-Cu joint is the smallest.Under the tensile-shearcondition, the mechanical performance of the joint is determined by the structure of interlock, the failure mode is therivet pull-out from the lower sheet.Under the peel condition, the mechanical performance of joint is determined by thestructure of interlock and the behavior of sheet material.If the strength of upper sheet is smaller, the rivet is pulled outfrom riveting hole on the upper sheet.If the strength of lower sheet is smaller, the rivet is pulled out from the lowersheet.If the strengthes of upper and lower sheets are big and identical, the rivet is also pulled out from the lower sheet.
The mechanical performance of self-piercing riveted (SPR) joint in aluminum and copper alloy (Al-Cu)sheets with different piercing directions is investigated experimentally, and the material properties are tested.Theformability of SPR Cu-Cu joint is analyzed by riveting experiment and finite element analysis.The mechanicalperformances of SPR joints in Al-Cu with different piercing directions are tested, and the load-displacement curves areobtained.The result show that the tensile-shear strength of SPR joint is higher than its peel strength.The strength of Cu-Cu joint is the highest, Cu-Al joint is the secondary and the Al-Cu joint is the smallest.Under the tensile-shearcondition, the mechanical performance of the joint is determined by the structure of interlock, the failure mode is therivet pull-out from the lower sheet.Under the peel condition, the mechanical performance of joint is determined by thestructure of interlock and the behavior of sheet material.If the strength of upper sheet is smaller, the rivet is pulled outfrom riveting hole on the upper sheet.If the strength of lower sheet is smaller, the rivet is pulled out from the lowersheet.If the strengthes of upper and lower sheets are big and identical, the rivet is also pulled out from the lower sheet.
2014, 33(10): 1579-1584.
doi: 10.13433/j.cnki.1003-8728.2014.102
Abstract:
The accordion cellular honeycomb has an increasing attention in the aviation industry over the lastdecade, because of the zero Poisson' s ratio and high-strain capability.In this paper, the accordion cellularhoneycomb is equivalent to a homogeneous orthogonal anisotropic plate.A novel analytical method for solving theequivalent flexural and torsional stiffness of the accordion cellular honeycomb was proposed based on the energyequivalence principle.And the analytical expressions of the equivalent stiffness were derived.Furthermore, theinfluence of the base cell structure parameters on the equivalent stiffness was studied.With the parameterized modelof the accordion cellular honeycomb being established, a set of inversion method based on the numerical simulationhas been used to obtain the equivalent stiffness.The comparisons between the theoretical results with the inversionresults show that the present analytical method is feasible and valid.
The accordion cellular honeycomb has an increasing attention in the aviation industry over the lastdecade, because of the zero Poisson' s ratio and high-strain capability.In this paper, the accordion cellularhoneycomb is equivalent to a homogeneous orthogonal anisotropic plate.A novel analytical method for solving theequivalent flexural and torsional stiffness of the accordion cellular honeycomb was proposed based on the energyequivalence principle.And the analytical expressions of the equivalent stiffness were derived.Furthermore, theinfluence of the base cell structure parameters on the equivalent stiffness was studied.With the parameterized modelof the accordion cellular honeycomb being established, a set of inversion method based on the numerical simulationhas been used to obtain the equivalent stiffness.The comparisons between the theoretical results with the inversionresults show that the present analytical method is feasible and valid.
2014, 33(10): 1585-1589.
doi: 10.13433/j.cnki.1003-8728.2014.1028
Abstract:
Based on one flying wing with multi-control surface and split rudder, the structural finite element modeland aerodynamic model were built.According to the characteristics of multi-control surfaces and split rudders themodification for aerodynamic model and structural model wereconducted, so the aeroelastic characteristics of theflying wing with split rudders are reasonable.The proposed modeling andcomputation method is practical.
Based on one flying wing with multi-control surface and split rudder, the structural finite element modeland aerodynamic model were built.According to the characteristics of multi-control surfaces and split rudders themodification for aerodynamic model and structural model wereconducted, so the aeroelastic characteristics of theflying wing with split rudders are reasonable.The proposed modeling andcomputation method is practical.
2014, 33(10): 1590-1593.
doi: 10.13433/j.cnki.1003-8728.2014.1029
Abstract:
The object of the study is the flap and slat motion mechanism.For simulating the real aircraft flightcondition, firstly, it meted the boundary conditions for the flap and slat by pressurizing rigidly on the box specimenof wing; secondly, using the single-point dual-actuator loading scheme, the changes of aerodynamic loads on theflap and slat motion mechanism under launch and retrieval conditions during takeoff and landing were simulated, bycontrolling size and the direction of actuator applied load.The study result of the test and analysis shows: the errorof the flap and slat each channel wing loading is less than 5%.The tracking loading method of locomotory wing forflap and slat is feasible and effective.
The object of the study is the flap and slat motion mechanism.For simulating the real aircraft flightcondition, firstly, it meted the boundary conditions for the flap and slat by pressurizing rigidly on the box specimenof wing; secondly, using the single-point dual-actuator loading scheme, the changes of aerodynamic loads on theflap and slat motion mechanism under launch and retrieval conditions during takeoff and landing were simulated, bycontrolling size and the direction of actuator applied load.The study result of the test and analysis shows: the errorof the flap and slat each channel wing loading is less than 5%.The tracking loading method of locomotory wing forflap and slat is feasible and effective.
2014, 33(10): 1594-1598.
doi: 10.13433/j.cnki.1003-8728.2014.1030
Abstract:
To explore the beneficial usage of profiled endwall in improving the performance of the axial flowcompressor rotor, Using the isentropic efficiency of rotor as the objective, the optimization of non-axisymmetricprofiled endwall was conducted on a subsonic axial flow compressor rotor by CFD simulations.By the flow analysisof the best optimization results, it can be concluded that the low velocity zone was reduced and the radial vortex wasalmost died out closing to suction side of the rotor tail near the hub.The inverse pressure difference was partlyweakened and the mixing flow loss and vortex loss was attenuated on the whole, which increased the isentropicefficiency of the rotor by 1.0%.
To explore the beneficial usage of profiled endwall in improving the performance of the axial flowcompressor rotor, Using the isentropic efficiency of rotor as the objective, the optimization of non-axisymmetricprofiled endwall was conducted on a subsonic axial flow compressor rotor by CFD simulations.By the flow analysisof the best optimization results, it can be concluded that the low velocity zone was reduced and the radial vortex wasalmost died out closing to suction side of the rotor tail near the hub.The inverse pressure difference was partlyweakened and the mixing flow loss and vortex loss was attenuated on the whole, which increased the isentropicefficiency of the rotor by 1.0%.
2014, 33(10): 1599-1603.
doi: 10.13433/j.cnki.1003-8728.2014.1031
Abstract:
Aiming at the problem caused by the highly coupled multi-parameters in aircraft design, firstly a networkgraph model of product design relationship is established, and the definition of the association values of parametersis studied; secondly, a method for design iteration control is proposed; and finally the evaluation objectives of themost optimal design path based on the density and depth of parameter association is obtained.This method has beenused in a design iteration process of an aircraft wing, and the obtained optimal design iteration path of the centralgirder strength indicated the high enhancement in the term of design efficiency.
Aiming at the problem caused by the highly coupled multi-parameters in aircraft design, firstly a networkgraph model of product design relationship is established, and the definition of the association values of parametersis studied; secondly, a method for design iteration control is proposed; and finally the evaluation objectives of themost optimal design path based on the density and depth of parameter association is obtained.This method has beenused in a design iteration process of an aircraft wing, and the obtained optimal design iteration path of the centralgirder strength indicated the high enhancement in the term of design efficiency.
2014, 33(10): 1604-1608.
doi: 10.13433/j.cnki.1003-8728.2014.1032
Abstract:
Aiming at the loading condition requirements of UAV (unmanned aerial vehicle) platform, themechanical structure of the small opto-electronic stabilized platform assembled on a UAV is designed in this paper.By analyzing the requirement of frame structure, function and specific parameters of the opto-electronic stabilizedplatform, the structure with two axis and three frames is chosen; the separated outer frame is designed andoptimized with weight reduction.This design can decrease the difficulty of assembly and the manufacturing costgreatly, the precision of the whole platform is also improved.Meanwhile, the opto-electronic stabilized platformmodel is built and its dynamics is simulated by using ADAMS software.
Aiming at the loading condition requirements of UAV (unmanned aerial vehicle) platform, themechanical structure of the small opto-electronic stabilized platform assembled on a UAV is designed in this paper.By analyzing the requirement of frame structure, function and specific parameters of the opto-electronic stabilizedplatform, the structure with two axis and three frames is chosen; the separated outer frame is designed andoptimized with weight reduction.This design can decrease the difficulty of assembly and the manufacturing costgreatly, the precision of the whole platform is also improved.Meanwhile, the opto-electronic stabilized platformmodel is built and its dynamics is simulated by using ADAMS software.
