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RSS2012 Vol. 31, No. 6
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2012, 31(6): 861-864.
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Abstract:
In order to improve the surface quality and reduce the surface roughness for inner surface groove of thick tubing, a device of magnetic-abrasive finishing was developed with Nd-Fe-B permanent magnets instead of electromagnet as built-in magnetic pole, after analyzing the magnetic field and the characteristics of inner circular surface. The device is simple in structure with smaller size and lighter weight, which is easy to assemble and disassemble, and needs no power supply, thus can be applied widely. The experiment conducted in which good surface quality has been obtained demonstrates that the performance of this device is superior to other finishing methods, so that it is an excellent finishing process for inner surface groove of thick tubing.
In order to improve the surface quality and reduce the surface roughness for inner surface groove of thick tubing, a device of magnetic-abrasive finishing was developed with Nd-Fe-B permanent magnets instead of electromagnet as built-in magnetic pole, after analyzing the magnetic field and the characteristics of inner circular surface. The device is simple in structure with smaller size and lighter weight, which is easy to assemble and disassemble, and needs no power supply, thus can be applied widely. The experiment conducted in which good surface quality has been obtained demonstrates that the performance of this device is superior to other finishing methods, so that it is an excellent finishing process for inner surface groove of thick tubing.
2012, 31(6): 865-868.
Abstract:
In the application of stress relaxation-forming process to form skin-panel part of small curvature and large size, springbaek is one of the main factors which influence the accuracy of the part's size and shape. In this paper the algorithm to compensate for springback is established by using the experience formula summarized from experimental data and the formula is used as the initial value of iteration. The iteration experiment of mold type surface is designed and used for validating the validity of the method which compensates the springback in the process of forming small curvature skin-panel in which the springback phenomenon is relatively serious.
In the application of stress relaxation-forming process to form skin-panel part of small curvature and large size, springbaek is one of the main factors which influence the accuracy of the part's size and shape. In this paper the algorithm to compensate for springback is established by using the experience formula summarized from experimental data and the formula is used as the initial value of iteration. The iteration experiment of mold type surface is designed and used for validating the validity of the method which compensates the springback in the process of forming small curvature skin-panel in which the springback phenomenon is relatively serious.
2012, 31(6): 869-872.
Abstract:
We numerically calculate the three-dimensional viscous flow field near the blade tip region at the near stall margin of a highly-loaded and forward-swept fan rotor. We compare the effects of the forward-swept fan rotor on the tip clearance vortex structure with those of a conventionally stacked radial rotor that has aerodynamically equal performance. The comparison results show that both the stall margin of the forward-swept fan rotor and the distribu-tion of its aerodynamic tip loading are improved. Our detailed analysis of its flow field reveals that the tip clearance vortex of the forward-swept fan rotor does not break under the near stall condition, thus providing a novel explanation why the tip clearance vortex structure of a forward-swept fan rotor is different from that of a conventional fan rotor.
We numerically calculate the three-dimensional viscous flow field near the blade tip region at the near stall margin of a highly-loaded and forward-swept fan rotor. We compare the effects of the forward-swept fan rotor on the tip clearance vortex structure with those of a conventionally stacked radial rotor that has aerodynamically equal performance. The comparison results show that both the stall margin of the forward-swept fan rotor and the distribu-tion of its aerodynamic tip loading are improved. Our detailed analysis of its flow field reveals that the tip clearance vortex of the forward-swept fan rotor does not break under the near stall condition, thus providing a novel explanation why the tip clearance vortex structure of a forward-swept fan rotor is different from that of a conventional fan rotor.
2012, 31(6): 873-876.
Abstract:
In this paper the topology optimization design of multi-loaded continuum structure is taken as a kind of structural unit pattern reeognition, and K Nearest Neighbor （KNN） method of pattern recognition is used to conduct the topology optimization design. The entire design region is taken as the initial sample space, and the element stresses under multi-load are regarded as the feature vectors, and the feature vectors' Euclidean distance is regarded as the recognition standard to classify all the unit samples into two classes so as to obtain the topology optimization result. Several examples of the topology optimization design are given and made based on KNN method. The results indicate that this design method is feasible.
In this paper the topology optimization design of multi-loaded continuum structure is taken as a kind of structural unit pattern reeognition, and K Nearest Neighbor （KNN） method of pattern recognition is used to conduct the topology optimization design. The entire design region is taken as the initial sample space, and the element stresses under multi-load are regarded as the feature vectors, and the feature vectors' Euclidean distance is regarded as the recognition standard to classify all the unit samples into two classes so as to obtain the topology optimization result. Several examples of the topology optimization design are given and made based on KNN method. The results indicate that this design method is feasible.
2012, 31(6): 877-882.
Abstract:
According to the characteristics of multi-stage forming, more information, variety types for aeroengine blade during forging process, an organizational method of blade forging process information based on multi-state model was proposed. According to the definition and state division of the blade forging process, the organizational form of status information and XML representation of status model were described in detail. Process information integrated application model based on multi-state model was given and the blade forging process information integrated platform was developed supporting the application of blade forging polymorphic model. Through the organizational form by the status of process as node, the classification and the reorganization for the blade forging process information were realized. This could facilitate process information management and be applicable to actual technical process, which could assure digital value transmission the logicality, continuity and integrity during the technical process.
According to the characteristics of multi-stage forming, more information, variety types for aeroengine blade during forging process, an organizational method of blade forging process information based on multi-state model was proposed. According to the definition and state division of the blade forging process, the organizational form of status information and XML representation of status model were described in detail. Process information integrated application model based on multi-state model was given and the blade forging process information integrated platform was developed supporting the application of blade forging polymorphic model. Through the organizational form by the status of process as node, the classification and the reorganization for the blade forging process information were realized. This could facilitate process information management and be applicable to actual technical process, which could assure digital value transmission the logicality, continuity and integrity during the technical process.
2012, 31(6): 883-887.
Abstract:
The damage evolutions of compression loaded composite laminates with circle cutout were simulated based on the three-dimension progressive damage model.Good agreement was found between the analytical and experimental results.The results showed that the ply stacking-sequence could significantly influence the damage propagations of each layer.Based on the validated finite element model,the influence of ply stacking-ratio on the strength of composite laminates was analysed.
The damage evolutions of compression loaded composite laminates with circle cutout were simulated based on the three-dimension progressive damage model.Good agreement was found between the analytical and experimental results.The results showed that the ply stacking-sequence could significantly influence the damage propagations of each layer.Based on the validated finite element model,the influence of ply stacking-ratio on the strength of composite laminates was analysed.
2012, 31(6): 888-892.
Abstract:
The numerical modeling techniques of 3D stretch bending for complex cross section is investigated in this paper. Firstly, the movements of jaws and arms of the stretch bending machine with force-controlled strategy are analyzed. The boundary conditions corresponding to the rotating arm, lifting arm and stretching arm are defined. Then, the material properties affected by age-hardening for rolling extrusion is studied. The effects of age-hardening are simulated by adjusting the strain-stress relation curves of the rolling parts. Based on the above modeling formulation together with the nonlinear finite element software MSC. Marc, a numerical stretch bending simulation for a car's doorframe with complex cross section is presented. The results show that the proposed boundary condition for 3D stretch bending simulation under force-controlled strategy is effective; the adjusting method for strain-stress curves can simulate the age-hardening effects, and can significantly improve the spring-back simulating accuracy for 3D stretch bending process.
The numerical modeling techniques of 3D stretch bending for complex cross section is investigated in this paper. Firstly, the movements of jaws and arms of the stretch bending machine with force-controlled strategy are analyzed. The boundary conditions corresponding to the rotating arm, lifting arm and stretching arm are defined. Then, the material properties affected by age-hardening for rolling extrusion is studied. The effects of age-hardening are simulated by adjusting the strain-stress relation curves of the rolling parts. Based on the above modeling formulation together with the nonlinear finite element software MSC. Marc, a numerical stretch bending simulation for a car's doorframe with complex cross section is presented. The results show that the proposed boundary condition for 3D stretch bending simulation under force-controlled strategy is effective; the adjusting method for strain-stress curves can simulate the age-hardening effects, and can significantly improve the spring-back simulating accuracy for 3D stretch bending process.
2012, 31(6): 893-897.
Abstract:
It is generally accepted that composite laminated plates with cutouts not only reduce the strength of struc tures but also have a serious effect on stability. Linear eigenvalue method is used to study stability of laminated plates under uniaxial compression. Flange reinforcement, single ring reinforcement, double ring reinforcement and center tube reinforcement are adopted to reinforce the stability of plates with cutouts. In the case of reinforcement structures having the same additional mass, better plans are got by comparing critical buckling loads. The best de sign range of reinforcement parameters such as flange on stability. These conclusions will provide references angle, flange height are obtained by studying their influence for stability reinforcement of cutouts structures.
It is generally accepted that composite laminated plates with cutouts not only reduce the strength of struc tures but also have a serious effect on stability. Linear eigenvalue method is used to study stability of laminated plates under uniaxial compression. Flange reinforcement, single ring reinforcement, double ring reinforcement and center tube reinforcement are adopted to reinforce the stability of plates with cutouts. In the case of reinforcement structures having the same additional mass, better plans are got by comparing critical buckling loads. The best de sign range of reinforcement parameters such as flange on stability. These conclusions will provide references angle, flange height are obtained by studying their influence for stability reinforcement of cutouts structures.
2012, 31(6): 898-905.
Abstract:
The paper presents an overview of the research on repair-replace strategies under product warranty at home and abroad,and introduces the basic theories and concepts of product warranty and warranty policy.The research of repair-replace strategy is classified under the index of maintenance category and deployment time and the purpose of optimization of repair-replace strategy is illustrated.Based on the above analysis,it summarizes and comments on the main contents and methods of repair-replace strategy under one-dimensional and two-dimensional product warranty.Some research findings are compared and analyzed further.Finally,it presents the exploratory outlook of further research on repair-replace strategy.
The paper presents an overview of the research on repair-replace strategies under product warranty at home and abroad,and introduces the basic theories and concepts of product warranty and warranty policy.The research of repair-replace strategy is classified under the index of maintenance category and deployment time and the purpose of optimization of repair-replace strategy is illustrated.Based on the above analysis,it summarizes and comments on the main contents and methods of repair-replace strategy under one-dimensional and two-dimensional product warranty.Some research findings are compared and analyzed further.Finally,it presents the exploratory outlook of further research on repair-replace strategy.
2012, 31(6): 906-909.
Abstract:
In order to overcome the application restriction of frequency domain subspace algorithm in modal parameter identification,a new subspace algorithm with segments of frequency domain（SFDS） is put forward in this paper.The SFDS algorithm segments the frequency domain data and re-computes the broad sense arithmetic operators to construct the new state equation and identifies the modal parameters.The simulation validation is carried out.The SFDS algorithm is used to identify the parameters of some variable section shaft.The result is consistent with the finite element result,so it is verified that the SFDS algorithm is effective.It is concluded that the SFDS algorithm can significantly reduce the computation volume,so can be realized on the common computing device.
In order to overcome the application restriction of frequency domain subspace algorithm in modal parameter identification,a new subspace algorithm with segments of frequency domain（SFDS） is put forward in this paper.The SFDS algorithm segments the frequency domain data and re-computes the broad sense arithmetic operators to construct the new state equation and identifies the modal parameters.The simulation validation is carried out.The SFDS algorithm is used to identify the parameters of some variable section shaft.The result is consistent with the finite element result,so it is verified that the SFDS algorithm is effective.It is concluded that the SFDS algorithm can significantly reduce the computation volume,so can be realized on the common computing device.
2012, 31(6): 910-914.
Abstract:
According to the vibration conditions and the fixture design standardization in vibration environment test, the fixture for the airborne equipment is designed with the help of the analysis of the complex airborne equipment structure and the model selection of vibrating test bench. The finite element modal analysis of the fixture is per formed based on the threedimension solid model, thus its natural frequency and vibrating mode are obtained. Fur thermore, the ＂Energy＂ magnifying cloud picture is drawn on the basis of the PSD spectral analysis of the fixture fi nite element model. The research and the relevant test show that the designed fixture has good stiffness and reasona ble quality factor, which can satisfy the fixture design requirements. The present approach can be applied to the de sign of vibration test fixture for large scale as well as complex structure.
According to the vibration conditions and the fixture design standardization in vibration environment test, the fixture for the airborne equipment is designed with the help of the analysis of the complex airborne equipment structure and the model selection of vibrating test bench. The finite element modal analysis of the fixture is per formed based on the threedimension solid model, thus its natural frequency and vibrating mode are obtained. Fur thermore, the ＂Energy＂ magnifying cloud picture is drawn on the basis of the PSD spectral analysis of the fixture fi nite element model. The research and the relevant test show that the designed fixture has good stiffness and reasona ble quality factor, which can satisfy the fixture design requirements. The present approach can be applied to the de sign of vibration test fixture for large scale as well as complex structure.
2012, 31(6): 915-918.
Abstract:
The method of fault diagnosis based on wavelet packet transform （WPT） and support vector machine （SVM） is presented. The vibration signals are decomposed using wavelet packet transform, and the energy of each frequency band is extracted as the fault features and input into support vector machine, then the fault pattern is rec ognized using SVM fault classifier. The proposed method is applied to the structure fault diagnosis of a tower crane, and the results of the experiment demonstrate that the proposed method is efficient in fauh diagnosis.
The method of fault diagnosis based on wavelet packet transform （WPT） and support vector machine （SVM） is presented. The vibration signals are decomposed using wavelet packet transform, and the energy of each frequency band is extracted as the fault features and input into support vector machine, then the fault pattern is rec ognized using SVM fault classifier. The proposed method is applied to the structure fault diagnosis of a tower crane, and the results of the experiment demonstrate that the proposed method is efficient in fauh diagnosis.
2012, 31(6): 919-923.
Abstract:
For the steer-by-wire system, the road feeling should be produced by simulation because there is no mechanical connection between the steering wheel and the front wheels. The dynamics model of steering wheel module and the aligning torque model of the mechanical steering system were established. According to the disadvantages of the fixed ratio in traditional steering system, a control strategy of road feeling based on variable transmission ratio was proposed. Small transmission ratio was used at the low speed in order to realize sensitive steering. Big transmission ratio was used at the high speed in order to realize stable steering. At the same time, modification of the road feeling was carried out according to the ideal road feeling expected by the driver, and the modification formula of the road feeling was derived finally. The simulation results showed that the road feeling control strategy could make good use of steer-by-wire system and satisfy the steering sensitivity at low speed and the steering stability at high speed. Fuzzy Proportion Integration Differentiation （PID） controller was designed to real-timely control the road feeling simulating motor.
For the steer-by-wire system, the road feeling should be produced by simulation because there is no mechanical connection between the steering wheel and the front wheels. The dynamics model of steering wheel module and the aligning torque model of the mechanical steering system were established. According to the disadvantages of the fixed ratio in traditional steering system, a control strategy of road feeling based on variable transmission ratio was proposed. Small transmission ratio was used at the low speed in order to realize sensitive steering. Big transmission ratio was used at the high speed in order to realize stable steering. At the same time, modification of the road feeling was carried out according to the ideal road feeling expected by the driver, and the modification formula of the road feeling was derived finally. The simulation results showed that the road feeling control strategy could make good use of steer-by-wire system and satisfy the steering sensitivity at low speed and the steering stability at high speed. Fuzzy Proportion Integration Differentiation （PID） controller was designed to real-timely control the road feeling simulating motor.
2012, 31(6): 924-927.
Abstract:
The transient responses of the offset single-disk rotor system under sudden unbalance load are investigated in this paper. The transient motion equation including acceleration terms is established based on Transfer Matrix Method （TMM）, in which the impacts of acceleration and damping are considered. The transient response of the system under sudden unbalance load has been simulated by Newmarkintegration method. Analysis result shows that a sudden unbalance on the operating system will cause larger oscillations but can be stabilized finally. The transient oscillation's amplitude and final steady value caused by the sudden unbalance are increased with the advance of the sudden unbalance, and it's a positive correlation approximately. This method contributes a good guidance for the design and intelligent fault diagnosis of aero-engine.
The transient responses of the offset single-disk rotor system under sudden unbalance load are investigated in this paper. The transient motion equation including acceleration terms is established based on Transfer Matrix Method （TMM）, in which the impacts of acceleration and damping are considered. The transient response of the system under sudden unbalance load has been simulated by Newmarkintegration method. Analysis result shows that a sudden unbalance on the operating system will cause larger oscillations but can be stabilized finally. The transient oscillation's amplitude and final steady value caused by the sudden unbalance are increased with the advance of the sudden unbalance, and it's a positive correlation approximately. This method contributes a good guidance for the design and intelligent fault diagnosis of aero-engine.
2012, 31(6): 928-932.
Abstract:
To solve the problem of the contact impact between missile and launch canister, we use the implicit scheme in the finite element's （FE） statics and the explicit scheme in FE dynamics to simulate a missile's charging and launching respectively. We use the composites launch canister's ply thickness and its lamination angle as the optimal design variables and define the launch canister's maximum displacement during missile launching and the launch canister's mass as optimization objectives. Taking into account the FE numerical calculation results, we use the Python language to develop the programs and the non-dominant sequencing genetic algorithm II （NSGA-II） which is based on the Pareto strategy to establish the multi-objective optimization model. With the optimization model, we obtain the Pareto front surface curve and the optimal solution. We use the specific stiffness structural ef-ficiency to' compare the performance of the launch canister before and after the optimization; the comparison results show that optimal design of the launch canister is effective.
To solve the problem of the contact impact between missile and launch canister, we use the implicit scheme in the finite element's （FE） statics and the explicit scheme in FE dynamics to simulate a missile's charging and launching respectively. We use the composites launch canister's ply thickness and its lamination angle as the optimal design variables and define the launch canister's maximum displacement during missile launching and the launch canister's mass as optimization objectives. Taking into account the FE numerical calculation results, we use the Python language to develop the programs and the non-dominant sequencing genetic algorithm II （NSGA-II） which is based on the Pareto strategy to establish the multi-objective optimization model. With the optimization model, we obtain the Pareto front surface curve and the optimal solution. We use the specific stiffness structural ef-ficiency to' compare the performance of the launch canister before and after the optimization; the comparison results show that optimal design of the launch canister is effective.
2012, 31(6): 933-937.
Abstract:
Precisely constructing turbulence wind model avails the whole system simulation, stable power control, system dynamics analysis and control system design of wind turbine. In order to solve weak real-time characters of ＂ turbulence generating, a design method of turbulence filter based real-time simulation is proposed in this paper. The real time turbulence wind can be acquired when Gaussian white noise goes through the designed turbulence fiter. The equivalent wind speed combining wind shear, tower shadow effect, turbulence and rotational sampling has been realized in software. The simulation results show that the generating system of equivalent wind speed based turbulence filter is practicable and effective.
Precisely constructing turbulence wind model avails the whole system simulation, stable power control, system dynamics analysis and control system design of wind turbine. In order to solve weak real-time characters of ＂ turbulence generating, a design method of turbulence filter based real-time simulation is proposed in this paper. The real time turbulence wind can be acquired when Gaussian white noise goes through the designed turbulence fiter. The equivalent wind speed combining wind shear, tower shadow effect, turbulence and rotational sampling has been realized in software. The simulation results show that the generating system of equivalent wind speed based turbulence filter is practicable and effective.
2012, 31(6): 938-941.
Abstract:
A method of analyzing and calculating contact fatigue life of aerospace bearing under arbitrary application load is presented in this paper. The input load data is transformed into stress according to the line-contact stress formula and fatigue equation of constantife. Bringing the stress into the commonly used empirical formula of high cycle fatigue, the amended contact fatigue life under arbitrary application load is obtained. Taking the bearing series MS21438 of the roller wheel track applied in wing flap mechanism as an example, its contact fatigue life is calculaed under its working load. Furthermore, we obtain the conclusion that the service life is prolonged obviously as the model number of bearings increases. The result could provide helpful reference for choosing aerospace bearing designation and confirming bearing's repair cycle.
A method of analyzing and calculating contact fatigue life of aerospace bearing under arbitrary application load is presented in this paper. The input load data is transformed into stress according to the line-contact stress formula and fatigue equation of constantife. Bringing the stress into the commonly used empirical formula of high cycle fatigue, the amended contact fatigue life under arbitrary application load is obtained. Taking the bearing series MS21438 of the roller wheel track applied in wing flap mechanism as an example, its contact fatigue life is calculaed under its working load. Furthermore, we obtain the conclusion that the service life is prolonged obviously as the model number of bearings increases. The result could provide helpful reference for choosing aerospace bearing designation and confirming bearing's repair cycle.
2012, 31(6): 942-946.
Abstract:
This paper investxgates me modeling, study on the model parameters. At first, the linear cylinder actuator is developed and manufactured and the electro mechanical performance is tested. Considering the constraint and boundary conditions of design, the actuator model is established according to Ogden and Yeoh strain energy functions. The model works well through test data verifi cation. For further stable control application, more simple models are also provided based on experiment data re gression and data fitting.
This paper investxgates me modeling, study on the model parameters. At first, the linear cylinder actuator is developed and manufactured and the electro mechanical performance is tested. Considering the constraint and boundary conditions of design, the actuator model is established according to Ogden and Yeoh strain energy functions. The model works well through test data verifi cation. For further stable control application, more simple models are also provided based on experiment data re gression and data fitting.
2012, 31(6): 947-951.
Abstract:
Because of the low credibility, subjectivity and blindness of the traditional fuzzy assessment method in determining the fuzzy relationship matrix and the multi-attribute weighting coefficients during evaluating the performance of an integrated avionics system, we propose an improved fuzzy assessment method which combines the classification and statistics theory, the entropy weighting a more scientific and objective assessment, we establish data so as to establish the fuzzy relationship matrix and method and the maximum deviation method. To guarantee a fuzzy evaluation parameter range, classify the simulation determine the weighting values of indicators by combining the entropy weighting method with the maximum deviation method. We use the AFDX （avionics full duplex switched ethernet） avionics system as an example and select the network load and delay time as evaluation indicators to evaluate the performance of the integrated avionics system with our improved fuzzy assessment method. The simulation results show that the evaluation with our improved fuzzy assessment method can obtain more credible resuits without any human subjectivity, thus verifying the validity of our method.
Because of the low credibility, subjectivity and blindness of the traditional fuzzy assessment method in determining the fuzzy relationship matrix and the multi-attribute weighting coefficients during evaluating the performance of an integrated avionics system, we propose an improved fuzzy assessment method which combines the classification and statistics theory, the entropy weighting a more scientific and objective assessment, we establish data so as to establish the fuzzy relationship matrix and method and the maximum deviation method. To guarantee a fuzzy evaluation parameter range, classify the simulation determine the weighting values of indicators by combining the entropy weighting method with the maximum deviation method. We use the AFDX （avionics full duplex switched ethernet） avionics system as an example and select the network load and delay time as evaluation indicators to evaluate the performance of the integrated avionics system with our improved fuzzy assessment method. The simulation results show that the evaluation with our improved fuzzy assessment method can obtain more credible resuits without any human subjectivity, thus verifying the validity of our method.
2012, 31(6): 952-957.
Abstract:
To enhance the efficiency of design process, we apply the genetic engineering methodology to the optimi zation of a product design process, propose a design process optimization method based on the design process gene by analyzing the relationship among genome, design process gene and design process characteristics, and then give the optimization process. According to different stages of design process, we divide the design process gene into task description gene, concept design gene, overall design gene, detailed design gene and technical design gene. We also give the components of every kind of design process gene. By analyzing the effect of design process gene mapping on recognizing the defects of design process gene, we draw the design process gene mapping and its de tailed structure.
To enhance the efficiency of design process, we apply the genetic engineering methodology to the optimi zation of a product design process, propose a design process optimization method based on the design process gene by analyzing the relationship among genome, design process gene and design process characteristics, and then give the optimization process. According to different stages of design process, we divide the design process gene into task description gene, concept design gene, overall design gene, detailed design gene and technical design gene. We also give the components of every kind of design process gene. By analyzing the effect of design process gene mapping on recognizing the defects of design process gene, we draw the design process gene mapping and its de tailed structure.
2012, 31(6): 958-963.
Abstract:
The energy property of mechatronic products is considered as the research object,and the concept of the energy-design factor is proposed and applied in the energy-optimizing design of the mechatronic products in the use stage.Based on the function analysis of products in the use stage,the energy-consuming information of products was extracted.For the use stage of products,the relationship between energy factors and energy consumption was analyzed by adopting the theory of bond graph,and the energy-consuming model was established.Then the energy-design factor was extracted and the energy design factors were applied to the energy-saving design of products in the use stage.A clutch of motorcycle was taken as an example of optimization,the results show the feasibility and effectiveness of the proposed method.
The energy property of mechatronic products is considered as the research object,and the concept of the energy-design factor is proposed and applied in the energy-optimizing design of the mechatronic products in the use stage.Based on the function analysis of products in the use stage,the energy-consuming information of products was extracted.For the use stage of products,the relationship between energy factors and energy consumption was analyzed by adopting the theory of bond graph,and the energy-consuming model was established.Then the energy-design factor was extracted and the energy design factors were applied to the energy-saving design of products in the use stage.A clutch of motorcycle was taken as an example of optimization,the results show the feasibility and effectiveness of the proposed method.
2012, 31(6): 964-967.
Abstract:
The surface quality of injection molding parts relates to the followup processing and product life. In or der to eliminate the defects and distorsion of the surface, the method of mould temperature control for directly heat ing the mold cavity by steam is presented, and the corresponding equipment was developed. This device is made of two subsystemswater steam purifying system and air cleansing system, it works in the way： the high temperature and pressure steam is passed into mold cavity to heat the surface of mold cavity, then the hot air is put into the mold cavity for clearing away the residual condensed water Programmable logic controller （PLC） is used to con trol the order and duration of the steam and the hot air, until the surface temperature reach the desired temperature. In this method,the metal of mould cores are heated for depth of only 1 mm ~ 2 mm form mold surface, so it only needs the very shorter warmup time and less electricity. The flow ability of meolten plastic, the temperature and pressure of the of its front are very high in this heating way, so the distorsion and the surface defects of the injection molding parts can be eliminated.
The surface quality of injection molding parts relates to the followup processing and product life. In or der to eliminate the defects and distorsion of the surface, the method of mould temperature control for directly heat ing the mold cavity by steam is presented, and the corresponding equipment was developed. This device is made of two subsystemswater steam purifying system and air cleansing system, it works in the way： the high temperature and pressure steam is passed into mold cavity to heat the surface of mold cavity, then the hot air is put into the mold cavity for clearing away the residual condensed water Programmable logic controller （PLC） is used to con trol the order and duration of the steam and the hot air, until the surface temperature reach the desired temperature. In this method,the metal of mould cores are heated for depth of only 1 mm ~ 2 mm form mold surface, so it only needs the very shorter warmup time and less electricity. The flow ability of meolten plastic, the temperature and pressure of the of its front are very high in this heating way, so the distorsion and the surface defects of the injection molding parts can be eliminated.
2012, 31(6): 968-971.
Abstract:
Based on the results of orthogonal test, belt grinding surface roughness prediction model of AZ91D mag nesium alloy is established using linear regression method. The significant tests of regression equation and regres sion coefficient are conducted and the model was optimized to improve the prediction precision. The results indicate that the model has reliability on the prediction of surface roughness, abrasive belt grinding pressure has certain in fluence on the surface roughness, and grain size of belt and the belt linear speed have high significant influence on surface roughness, while the contact wheel hardness and workpiece axial on surface roughness. feeding speed have no significant influence.
Based on the results of orthogonal test, belt grinding surface roughness prediction model of AZ91D mag nesium alloy is established using linear regression method. The significant tests of regression equation and regres sion coefficient are conducted and the model was optimized to improve the prediction precision. The results indicate that the model has reliability on the prediction of surface roughness, abrasive belt grinding pressure has certain in fluence on the surface roughness, and grain size of belt and the belt linear speed have high significant influence on surface roughness, while the contact wheel hardness and workpiece axial on surface roughness. feeding speed have no significant influence.
2012, 31(6): 972-976.
Abstract:
Aiming at the composite fault diagnosis of the rotor failure and weak roller bearing fault， a fault diagnosis method was proposed based on the wavelet transform and the ensemble empirical mode decomposition by separating the coupling features of the composite fault and extracting the frequency of fault signals.Firstly original signals were decomposed and reconstructed by using the wavelet.Then non-modulation low-frequency fault feature was extracted using FFT for the low-frequency signals obtained from the decomposition and reconstruction of original signals.The high-frequency modulated signals from the decomposition and reconstruction of original were analyzed by envelop demodulation based on the ensemble empirical mode decomposition (EEMD)，and the modulated fault feature was extracted.Analyzing results of engineering signals indicated that the method can extract the composite fault feature of rolling bearings successfully.
Aiming at the composite fault diagnosis of the rotor failure and weak roller bearing fault， a fault diagnosis method was proposed based on the wavelet transform and the ensemble empirical mode decomposition by separating the coupling features of the composite fault and extracting the frequency of fault signals.Firstly original signals were decomposed and reconstructed by using the wavelet.Then non-modulation low-frequency fault feature was extracted using FFT for the low-frequency signals obtained from the decomposition and reconstruction of original signals.The high-frequency modulated signals from the decomposition and reconstruction of original were analyzed by envelop demodulation based on the ensemble empirical mode decomposition (EEMD)，and the modulated fault feature was extracted.Analyzing results of engineering signals indicated that the method can extract the composite fault feature of rolling bearings successfully.
2012, 31(6): 977-981.
Abstract:
Aiming at the composite fault diagnosis of the rotor failure and weak roller bearing fault, a fault diagnosis method was proposed based on the wavelet transform and the ensemble empirical mode decomposition by separating the coupling features of the composite fault and extracting the frequency of fault signals. Firstly original signals were decomposed and reconstructed by using the wavelet. Then non-modulation low-frequency fault feature was extracted using FFT for the low-frequency signals obtained from the decomposition and reconstruction of original signals. The high-frequency modulated signals from the decomposition and reconstruction of original were analyzed by envelop demodulation based on the ensemble empirical mode decomposition （EEMD）, and the modulated fault feature was extracted. Analyzing results of engineering signals indicated that the method can extract the composite fault feature of rollin bearings successfully.
Aiming at the composite fault diagnosis of the rotor failure and weak roller bearing fault, a fault diagnosis method was proposed based on the wavelet transform and the ensemble empirical mode decomposition by separating the coupling features of the composite fault and extracting the frequency of fault signals. Firstly original signals were decomposed and reconstructed by using the wavelet. Then non-modulation low-frequency fault feature was extracted using FFT for the low-frequency signals obtained from the decomposition and reconstruction of original signals. The high-frequency modulated signals from the decomposition and reconstruction of original were analyzed by envelop demodulation based on the ensemble empirical mode decomposition （EEMD）, and the modulated fault feature was extracted. Analyzing results of engineering signals indicated that the method can extract the composite fault feature of rollin bearings successfully.
2012, 31(6): 982-986.
Abstract:
The nonlinear blind source separation algorithm based on kernel function has been widely applied in blind signal processing.However the learning rate of traditional kernel function method is fixed.When the system noise level and iterative error are large,it will take a long time for iterative parameters to get convergence.So it will affect the efficiency of blind source separation.In this paper,a variable rate nonlinear blind source separation algorithm based on kernel function was proposed.The learning rate of the algorithm was adjusted according to SNR and iterative error.The algorithm was applied in gear faults diagnosis.Both of the results of simulation and experiment indicate that the present algorithm has better ability of noise reduction and feature extraction than fixed rate nonlinear blind source separation.
The nonlinear blind source separation algorithm based on kernel function has been widely applied in blind signal processing.However the learning rate of traditional kernel function method is fixed.When the system noise level and iterative error are large,it will take a long time for iterative parameters to get convergence.So it will affect the efficiency of blind source separation.In this paper,a variable rate nonlinear blind source separation algorithm based on kernel function was proposed.The learning rate of the algorithm was adjusted according to SNR and iterative error.The algorithm was applied in gear faults diagnosis.Both of the results of simulation and experiment indicate that the present algorithm has better ability of noise reduction and feature extraction than fixed rate nonlinear blind source separation.
2012, 31(6): 987-990.
Abstract:
To design the box optimization system of YND100 series decelerator of Huai'an Jinxiang Decelerator Fac tory, we put forward the optimal design scheme for the parametric procedural programming language of APDL which is based on the ANSYS software. We present the software's optimal design principle, establish the box optimization mathematical model that uses the minimum volume of the box as objective function and apply the APDL to the para metric modeling of the box optimization system. We give the APDL and VC + + 6.0 nested programming method and the interface of VC + + 6.0 and ANSYS and use the VC + + 6.0 to develop a good interface for the box optimi zation system. We also examine the actual optimization results that are useful for improving the structure of the de celerator box and for the optimal design of the factory's other types of decelerator.
To design the box optimization system of YND100 series decelerator of Huai'an Jinxiang Decelerator Fac tory, we put forward the optimal design scheme for the parametric procedural programming language of APDL which is based on the ANSYS software. We present the software's optimal design principle, establish the box optimization mathematical model that uses the minimum volume of the box as objective function and apply the APDL to the para metric modeling of the box optimization system. We give the APDL and VC + + 6.0 nested programming method and the interface of VC + + 6.0 and ANSYS and use the VC + + 6.0 to develop a good interface for the box optimi zation system. We also examine the actual optimization results that are useful for improving the structure of the de celerator box and for the optimal design of the factory's other types of decelerator.
2012, 31(6): 991-995.
Abstract:
We use the AMESim software to establish the separate models of powersplit continuously variable trans mission（PSCVT） and its matching engine. Through integration, we establish the power model and economic simu lation model of the vehicle equipped with PSCVT. We simulate the models with the European ECE15 test regula tions; the simulation results show that the fuel economy of the vehicle equipped with PSCVT is much better than that of the vehicle equipped with fivespeed manual transmission although its acceleration performance is slightly poorer.
We use the AMESim software to establish the separate models of powersplit continuously variable trans mission（PSCVT） and its matching engine. Through integration, we establish the power model and economic simu lation model of the vehicle equipped with PSCVT. We simulate the models with the European ECE15 test regula tions; the simulation results show that the fuel economy of the vehicle equipped with PSCVT is much better than that of the vehicle equipped with fivespeed manual transmission although its acceleration performance is slightly poorer.
2012, 31(6): 996-998.
Abstract:
In order to extract fault features of weak signal from the strong noise, a new denoising method based on balance orthogonal multiwavelet is proposed. Muhiwavelet has several scaling functions and wavelet functions, and matches different characteristics of signals, and possesses the excellent properties that scalar wavelet cannot satisfy simultaneously. Moreover, the balance orthogonal muhiwavelet can avoid the Gibbs phenomena and their processes have the advantages in denoising. The algorithm and the implementation steps of this denoising method are de scribed. The experimental comparison of the denoising effect between this method and the traditional multiwavelet algorithm was done. The experiments indicate that this method can extract the fault feature submerged in a heavy noise and maintain signal smoothness.
In order to extract fault features of weak signal from the strong noise, a new denoising method based on balance orthogonal multiwavelet is proposed. Muhiwavelet has several scaling functions and wavelet functions, and matches different characteristics of signals, and possesses the excellent properties that scalar wavelet cannot satisfy simultaneously. Moreover, the balance orthogonal muhiwavelet can avoid the Gibbs phenomena and their processes have the advantages in denoising. The algorithm and the implementation steps of this denoising method are de scribed. The experimental comparison of the denoising effect between this method and the traditional multiwavelet algorithm was done. The experiments indicate that this method can extract the fault feature submerged in a heavy noise and maintain signal smoothness.
2012, 31(6): 999-1004.
Abstract:
An automatic registration algorithm of facial data in binocular stereo measurement is proposed.Firstly,the point features are extracted from the facial images in different views,and then the corresponding point matches are steadily established between the images.Secondly,the five-point algorithm is employed to compute the relative pose between the two views to realize the auto-registration of 3D facial data.It is unnecessary to use markers for assistance or select the features by hand.Experiments demonstrate the validity and robustness of the proposed algorithm.
An automatic registration algorithm of facial data in binocular stereo measurement is proposed.Firstly,the point features are extracted from the facial images in different views,and then the corresponding point matches are steadily established between the images.Secondly,the five-point algorithm is employed to compute the relative pose between the two views to realize the auto-registration of 3D facial data.It is unnecessary to use markers for assistance or select the features by hand.Experiments demonstrate the validity and robustness of the proposed algorithm.
2012, 31(6): 1005-1009.
Abstract:
A method of structure design and characteristic calculation for an annular ring pressure-regulating valve was proposed with formula. The coordinates calculation of the valve section are formulated and the computing code for the aerodynamic characteristic of pressureegulating valve were developed. This method was proved credible by comparing calculated data with experimental ones. The stagnation temperature in wind tunnel chamber and the testing time were also discussed.
A method of structure design and characteristic calculation for an annular ring pressure-regulating valve was proposed with formula. The coordinates calculation of the valve section are formulated and the computing code for the aerodynamic characteristic of pressureegulating valve were developed. This method was proved credible by comparing calculated data with experimental ones. The stagnation temperature in wind tunnel chamber and the testing time were also discussed.
2012, 31(6): 1010-1015,1022.
Abstract:
The main contents of this paper are focused on the surface geometrical dimension （ contour errors and ge ometrical dimensions） of the neck polishing of crankshaft connecting rod. A abrasive belt followed online pneumat ic system for measuring the roundness errors and diameter of crankshaft's neck is presented. After analyzing the movement control model of the followup tracing system. The constraint conditions are obtained, which can fill the requirements of uniform sampling of the sensor group. The errors of the system analyzed. Based on these, three sensor followup tracing principle is put forward,which can separate the crankpin's roundness errors and systematic errors from the actual measurement data. According to the principle of DFT （ Discrete Fourier Transform）, the fun damental equations of the threesensor tracing principle are deduced. By contrasting the results of this online meas urement system and the results of the tranditional offline method measured roundness, the relative error is about 4%, the proposed system has a higher measurement precision.
The main contents of this paper are focused on the surface geometrical dimension （ contour errors and ge ometrical dimensions） of the neck polishing of crankshaft connecting rod. A abrasive belt followed online pneumat ic system for measuring the roundness errors and diameter of crankshaft's neck is presented. After analyzing the movement control model of the followup tracing system. The constraint conditions are obtained, which can fill the requirements of uniform sampling of the sensor group. The errors of the system analyzed. Based on these, three sensor followup tracing principle is put forward,which can separate the crankpin's roundness errors and systematic errors from the actual measurement data. According to the principle of DFT （ Discrete Fourier Transform）, the fun damental equations of the threesensor tracing principle are deduced. By contrasting the results of this online meas urement system and the results of the tranditional offline method measured roundness, the relative error is about 4%, the proposed system has a higher measurement precision.
2012, 31(6): 1016-1022.
Abstract:
In this paper, it is firstly analyzed which the project demand of digitalized process and introduced the Supporting Environment with the model of information transferring in aircraft development, and then presented a al gorithm, which maps the configuration model based on BOM to process model based on PetriNet, using task model based on WBS as a transition. According to the algorithm, a multilayered process meeting different departments at different stages of process management on requirement is given. With the use of tasks planning, crated by Gantt chart, business process of complicated airplane manufacturing can be controlled automatically gen effectively.
In this paper, it is firstly analyzed which the project demand of digitalized process and introduced the Supporting Environment with the model of information transferring in aircraft development, and then presented a al gorithm, which maps the configuration model based on BOM to process model based on PetriNet, using task model based on WBS as a transition. According to the algorithm, a multilayered process meeting different departments at different stages of process management on requirement is given. With the use of tasks planning, crated by Gantt chart, business process of complicated airplane manufacturing can be controlled automatically gen effectively.
2012, 31(6): 1023-1026,1032.
Abstract:
In this paper, two simple and practical kinds of 2DOF parallel mechanisms （ mechanism of type I and mechanism of type Ⅱ ） were proposed, which can be used as the actuator for plane sprayer. The direct and inverse kinematics solutions were derived of the two kinds of mechanisms on the terminal operating point （ spray gun posi tion）. And then workspace dimension of the two kinds of mechanisms were compared and analyzed with the same parameters. The present result evidenced that mechanism of type II owned larger workspace. The kinematics models of the two mechanisms which do the same trajectory were simulated by examples using Matlab, variation of mecha nism kinematics parameters were obtained. The results which kinematics performance of type I was superior to type II were derived by comparison. The research of this paper provided the basis for the selection of mechanism, trajec tory planning of the spray gun of the sprayer design, and offered practical value for improving effectiveness of the spray.
In this paper, two simple and practical kinds of 2DOF parallel mechanisms （ mechanism of type I and mechanism of type Ⅱ ） were proposed, which can be used as the actuator for plane sprayer. The direct and inverse kinematics solutions were derived of the two kinds of mechanisms on the terminal operating point （ spray gun posi tion）. And then workspace dimension of the two kinds of mechanisms were compared and analyzed with the same parameters. The present result evidenced that mechanism of type II owned larger workspace. The kinematics models of the two mechanisms which do the same trajectory were simulated by examples using Matlab, variation of mecha nism kinematics parameters were obtained. The results which kinematics performance of type I was superior to type II were derived by comparison. The research of this paper provided the basis for the selection of mechanism, trajec tory planning of the spray gun of the sprayer design, and offered practical value for improving effectiveness of the spray.
2012, 31(6): 1027-1032.
Abstract:
Aiming at the problems of low level of information sharing,slow transmission of information,repetitive work in the design process of serial mechanical products,we present a new method of parametric collaborative design which is network-oriented.We analyze the information sharing conflicts and network heterogeneity in the distributed collaborative design and propose a method for building a collaborative design platform based on PDMWorks Workgroup.By studying the mechanisms of role distribution and concurrent control of data,we formulate the communication mechanism of the network-oriented collaborative design.Considering the structural characteristics of an overhead traveling crane,we combine the parametric variant design with the collaborative design,develop the overhead traveling crane's parametric collaborative design system which is network-oriented and verify our new method with the design of a main girder.
Aiming at the problems of low level of information sharing,slow transmission of information,repetitive work in the design process of serial mechanical products,we present a new method of parametric collaborative design which is network-oriented.We analyze the information sharing conflicts and network heterogeneity in the distributed collaborative design and propose a method for building a collaborative design platform based on PDMWorks Workgroup.By studying the mechanisms of role distribution and concurrent control of data,we formulate the communication mechanism of the network-oriented collaborative design.Considering the structural characteristics of an overhead traveling crane,we combine the parametric variant design with the collaborative design,develop the overhead traveling crane's parametric collaborative design system which is network-oriented and verify our new method with the design of a main girder.
