Human errors of seven types of armored equipment, which occur during the course of field test, are statistically analyzed. The human error-to-armored equipment failure ratio is obtained. The causes of human errors are...Human errors of seven types of armored equipment, which occur during the course of field test, are statistically analyzed. The human error-to-armored equipment failure ratio is obtained. The causes of human errors are analyzed. The distribution law of human errors is acquired. The ratio of human errors and human reliability index are also calculated.展开更多
Vibration monitoring and vibration severity evaluation of armored vehicle transmission are realized by additional sensors. An algorithm of vibration severity in frequency domain is presented. The algorithm has powerfu...Vibration monitoring and vibration severity evaluation of armored vehicle transmission are realized by additional sensors. An algorithm of vibration severity in frequency domain is presented. The algorithm has powerful applicability for signal type and flexible selectivity for frequency range,and avoids the processing of signal conversion used calculus and filtering compared to the algorithm of vibration severity in time domain. An applied example is given in company with attentive proceedings and measures for improving evaluation effect.展开更多
When the mechanical drive is changed into the electric transmission,the cooling system of the engine compartment should be altered to meet the new requirement for the increasing in equipment such as electric apparatus...When the mechanical drive is changed into the electric transmission,the cooling system of the engine compartment should be altered to meet the new requirement for the increasing in equipment such as electric apparatus.In order to predict and analyze the rationality of cooling system in the virtual engine compartment,the numerical simulation of airflow fields in the engine compartment by using computational fluid dynamics(CFD) technique is necessary.An armored vehicle with electric transmission in the research is taken as the research object.The physical model and mathematical model for the computation of 3D air flow and heat transfer in the engine compartment of an armored vehicle with electric transmission is established.Turbulent flow in the compartment is described by using the standard k-ε two-equation turbulence model.The temperature and velocity fields of 3D air flow in the engine compartment are numerically simulated and analyzed based on different fan's flux.A theoretical basis for determination of the fan's flux is given by the simulation results.The positions of the air-vent shutter are analyzed.The simulation results show that the different positions of the air-vent shutter can lead to different cooling efficiencies.展开更多
Aimed at the difficulties in analyzing the buffer characteristics of airbag system by using thermodynamic or experimental method only,the finite element method was used to establish nonlinear models for heavy equipmen...Aimed at the difficulties in analyzing the buffer characteristics of airbag system by using thermodynamic or experimental method only,the finite element method was used to establish nonlinear models for heavy equipment and its airbag system.The models' efficiency and correctness were validated by using on-site experiment data in vehicle airdrop landing.The simulation results agree very well with the experiment results.Then,the environment adaptability of airbag system of heavy equipment under high-altitude condition was studied by using the models.Finally,some solutions were given to solve the overturn problem in the landing.展开更多
A simulation model for a certain diesel engine cooling system is set up by using GT-COOL. The backwater temperature response in different operating conditions is simulated numerically. The effects of single or multipl...A simulation model for a certain diesel engine cooling system is set up by using GT-COOL. The backwater temperature response in different operating conditions is simulated numerically. The effects of single or multiple system parameters on the water temperature are analyzed. The results show that, changing different single parameters, the time taken for the steady backwater temperature is different, but relatively short;and if multiple parameters are changed, the time will be longer. Referred to the thermal balance test, the simulation results are validated and provide a basis for the intelligent control of the cooling system.展开更多
The semiconductor CdSeS quantum dots （QDs） embedded in glass are analysed by means of absorption spectra, photoluminescence （PL） spectra and photoluminescence excitation （PLE） spectra. The peaks of absorption sp...The semiconductor CdSeS quantum dots （QDs） embedded in glass are analysed by means of absorption spectra, photoluminescence （PL） spectra and photoluminescence excitation （PLE） spectra. The peaks of absorption spectra shift to lower energies with the size of QD increasing, which obviously shows a quantum-size effect. Using the PLE spectra, the physical origin of the lowest absorption peak is analysed. In PLE spectra, the lowest absorption peak can be deconvoluted into two peaks that stem from the transitions of 1S3/2-1Se and 2S3/2-1Se respectively. The measured energy difference between the two peaks is found to decrease with the size of QD increasing, which agrees well with the theoretical calculation for the two transitions. The luminescence peak of defect states is also analysed by PLE spectra. Two transitions are present in the PLE, which indicates that the transitions of 1S3/2 1Se and 2S3/2 1Se are responsible for the defect states luminescence.展开更多
A finite element model of vehicle and its airbag landing attenuation system is established and verified experimentally.Two design cases are selected to constrain the airbag design for extreme landing conditions,while ...A finite element model of vehicle and its airbag landing attenuation system is established and verified experimentally.Two design cases are selected to constrain the airbag design for extreme landing conditions,while the height and width of airbag and the area of vent hole are chosen as design variables.The optimization is forced to compromise the design variables between the conflicting requirements of the two extremes.In order to optimize the parameters of airbag,the multi-dimensional response surfaces based on extended Latin hypercube design and radial basis function are employed instead of the complex finite element model.Pareto optimal solution sets based on response surfaces are then obtained by multi-objective genetic algorithm.The results show the optimization method presented in this paper is a practical tool for the optimization of airbag landing attenuation system for heavy airdrop.展开更多
The electric transmission system congfiguration-2 is one of the main electric drives for tracked vehicles. The geometrical model for the power-train cabin is established and the preliminary design for its cooling syst...The electric transmission system congfiguration-2 is one of the main electric drives for tracked vehicles. The geometrical model for the power-train cabin is established and the preliminary design for its cooling system is implemented. The mathematic model is established for thermal current field computation, simulation and analysis in the powertrain cabin. The three-dimensional structure of the powertrain cabin is optimized. The validity of the cooling system design is proved. The foundation for optimizing the whole electric transmission system configuration is laid.展开更多
To predict the erosion and abrasion of high bore pressure tank gun barrel, the least square support vector machine (LSSVM) algorithm was used. Based on the gun firing test data, the prediction model for barrel's e...To predict the erosion and abrasion of high bore pressure tank gun barrel, the least square support vector machine (LSSVM) algorithm was used. Based on the gun firing test data, the prediction model for barrel's erosion and abrasion was established. It was adopted to predict the wear increment of gun barrel. The results show that the prediction values given by the model coincide with the measured data better, and the model can predict the barrel's wear accurately and rapidly.展开更多
The analytic surface plasmon polaritons （SPPs） dispersion relation is studied in a system consisting of a thin metallic film bounded by two sides media of nonlinear dielectric of arbitrary nonlinearity is studied by...The analytic surface plasmon polaritons （SPPs） dispersion relation is studied in a system consisting of a thin metallic film bounded by two sides media of nonlinear dielectric of arbitrary nonlinearity is studied by applying a generalised first integral approach. We consider both asymmetric and symmetric structures. Especially, in the symmetric system, two possible modes can exist： the odd mode and the even mode. The dispersion relations of the two modes are obtained. Due to the nonlinear dielectric, the magnitude of the electric field at the interface appears and alters the dispersion relations. The changes in SPPs dispersion relations depending on film thicknesses and nonlinearity are studied.展开更多
The acoustic vibration signal of tank is disassembled into the sum of intrinsic mode function （IMF） by multi-resolution empirical mode decomposition （EMD） method. The instantaneous frequency is obtained, and featu...The acoustic vibration signal of tank is disassembled into the sum of intrinsic mode function （IMF） by multi-resolution empirical mode decomposition （EMD） method. The instantaneous frequency is obtained, and feature transformation matrix is figured out by class scatter matrix. Multi- dimensional scale energy vector is mapped into low-dimensional eigenvector, and classification extraction is realized. This method sufficiently separates of different sound target features. The test result indicates that it is effective.展开更多
Structures of two classes of solvable subgroups in SL（3, C） are given in this paper, and the integrability of the 3-order Fuchsian equation which is integrable in the sense that its monodromy group is solvable is di...Structures of two classes of solvable subgroups in SL（3, C） are given in this paper, and the integrability of the 3-order Fuchsian equation which is integrable in the sense that its monodromy group is solvable is discussed.展开更多
Aimed at the requirements for electric transmission system of a military tracked vehicle, the motor's design indexes were analysed and calculated. A model based on saturate inductance parameter of interior permane...Aimed at the requirements for electric transmission system of a military tracked vehicle, the motor's design indexes were analysed and calculated. A model based on saturate inductance parameter of interior permanent magnet (IPM) synchronous motor was brought forward by using finite element analysis. And its control strategy based on the largest running capability was studied also. The experiment results for a scale model show that the modelling method improves the model's accuracy, and the motor's control strategy is effective.展开更多
A set of metallic specimens containing fatigue cracks with different sizes were tested using eddy current pulsed thermography(ECPT),therefore the relations between heating response of the crack area and the crack leng...A set of metallic specimens containing fatigue cracks with different sizes were tested using eddy current pulsed thermography(ECPT),therefore the relations between heating response of the crack area and the crack length was studied.The numerical and experimental results both showed that the increase of the crack length enhanced the crack heating response under specific test conditions.A particular form of calculated response signal,which is linearly related to the crack length,was introduced to provide a quantitative evaluation of crack length.展开更多
A novel energy-regenerative active suspension(NEAS) system was designed to solve the problem of low energy recovery efficiency caused by frequent alternation of energy-recovery mode and active-control mode in a tradit...A novel energy-regenerative active suspension(NEAS) system was designed to solve the problem of low energy recovery efficiency caused by frequent alternation of energy-recovery mode and active-control mode in a traditional energyregenerative active suspension(TEAS) system. The energy recovery and active control could be implemented simultaneously in the NEAS. The transforming processes and the corresponding computational formulas of power conversion in the NEAS were provided. The simulation results show that the performances of energy recovery of the NEAS are improved, and the selfsustaining of power supply for the NEAS can be realized.展开更多
A computational fluid dynamics(CFD)calculation model for the airflow and heat transfer in an armored vehicle cooling wind tunnel is established.A practical method to determine computation region outside power train co...A computational fluid dynamics(CFD)calculation model for the airflow and heat transfer in an armored vehicle cooling wind tunnel is established.A practical method to determine computation region outside power train compartment,produce grid and ensure grid quality is put forward.A commercial software FLUENT can be used to obtain solutions numerically in 3-D space.Precision of CFD calculation results is verified.The CFD model is used in designing a vehicle cooling wind tunnel,and air flow resistance of fan blast baffle is calculated.The calculated results show feasibility of the CFD model and the method.展开更多
Both the traverse subsystem and the elevation subsystem of the all-electrical tank gun control system are composed of electrical drive control system respectively. The parameters of PI regulator in these electrical dr...Both the traverse subsystem and the elevation subsystem of the all-electrical tank gun control system are composed of electrical drive control system respectively. The parameters of PI regulator in these electrical drive control systems affect the performance of the control system seriously. Up to now, there is not a simple and practical method for choosing regulator parameters, which are usually determined by repeated and continual readjustment. This method is low efficient, and the parameters got are not always optimal. A method for on-line adjusting the parameters of PI regulator in the electrical drive control system by computer program is introduced in this paper. The function of adjusting PI parameters of the electrical drive control system is realized by PC program written by VC++ and controlling program written by assemble language and by the communication between PC and DSP completed by the control MSCOMM in VC++6.0. The method as mentioned above which is applied for an all-electrical tank gun control system under development is proved very available, a better performance might be obtained for the all-electrical tank gun control system easily.展开更多
To know the temperature status of track and wheels on tank,the finite element calculation of temperature field was implemented with ANSYS software.The detailed temperature distributions for road wheel,drive wheel,idle...To know the temperature status of track and wheels on tank,the finite element calculation of temperature field was implemented with ANSYS software.The detailed temperature distributions for road wheel,drive wheel,idle wheel and track loop were obtained.The effect of factors,such as tank speed,environment temperature,sun radiant energy,ground deformation resistant and tank load,on the temperature of road wheel was studied.The sensitivity analysis shows that the effect of tank load on the temperature is the most,and the effect of ground deformation resistant is the least.The temperature testing device for road wheel on tank was developed to perform the experiments in real time.The calculated temperatures are in accord well with the experimental values.展开更多
Over recent years the progress in actuator and microelectronics technology has made intelligent suspension systems feasible.Based on conventional vane hydraulic damper,a new vane magneto-rheological fluid(MRF) damper ...Over recent years the progress in actuator and microelectronics technology has made intelligent suspension systems feasible.Based on conventional vane hydraulic damper,a new vane magneto-rheological fluid(MRF) damper with fail-safe capability is designed.Firstly,the mathematical model of damping moment is deduced based on the parallel-plate model and Bingham model of MR fluids.Secondly,some influence factors of damping adjustable multiple are analyzed to provide some ways for augmenting the damping adjustable multiple under the condition of keeping initial damping moment invariable.Finally,the magnetic circuit is designed,and magnetic field distribution is simulated with the magnetic finite element analysis software-ANSOFT.The theory and simulation results confirm that the damping adjustable range of vane MRF damper can meet the requirement of heavy vehicle semi-active suspension system.展开更多
文摘Human errors of seven types of armored equipment, which occur during the course of field test, are statistically analyzed. The human error-to-armored equipment failure ratio is obtained. The causes of human errors are analyzed. The distribution law of human errors is acquired. The ratio of human errors and human reliability index are also calculated.
基金Sponsored by National Defense Science and Technology Key Lab Foundation of China (51457120104JB3505)
文摘Vibration monitoring and vibration severity evaluation of armored vehicle transmission are realized by additional sensors. An algorithm of vibration severity in frequency domain is presented. The algorithm has powerful applicability for signal type and flexible selectivity for frequency range,and avoids the processing of signal conversion used calculus and filtering compared to the algorithm of vibration severity in time domain. An applied example is given in company with attentive proceedings and measures for improving evaluation effect.
文摘When the mechanical drive is changed into the electric transmission,the cooling system of the engine compartment should be altered to meet the new requirement for the increasing in equipment such as electric apparatus.In order to predict and analyze the rationality of cooling system in the virtual engine compartment,the numerical simulation of airflow fields in the engine compartment by using computational fluid dynamics(CFD) technique is necessary.An armored vehicle with electric transmission in the research is taken as the research object.The physical model and mathematical model for the computation of 3D air flow and heat transfer in the engine compartment of an armored vehicle with electric transmission is established.Turbulent flow in the compartment is described by using the standard k-ε two-equation turbulence model.The temperature and velocity fields of 3D air flow in the engine compartment are numerically simulated and analyzed based on different fan's flux.A theoretical basis for determination of the fan's flux is given by the simulation results.The positions of the air-vent shutter are analyzed.The simulation results show that the different positions of the air-vent shutter can lead to different cooling efficiencies.
文摘Aimed at the difficulties in analyzing the buffer characteristics of airbag system by using thermodynamic or experimental method only,the finite element method was used to establish nonlinear models for heavy equipment and its airbag system.The models' efficiency and correctness were validated by using on-site experiment data in vehicle airdrop landing.The simulation results agree very well with the experiment results.Then,the environment adaptability of airbag system of heavy equipment under high-altitude condition was studied by using the models.Finally,some solutions were given to solve the overturn problem in the landing.
文摘A simulation model for a certain diesel engine cooling system is set up by using GT-COOL. The backwater temperature response in different operating conditions is simulated numerically. The effects of single or multiple system parameters on the water temperature are analyzed. The results show that, changing different single parameters, the time taken for the steady backwater temperature is different, but relatively short;and if multiple parameters are changed, the time will be longer. Referred to the thermal balance test, the simulation results are validated and provide a basis for the intelligent control of the cooling system.
文摘The semiconductor CdSeS quantum dots （QDs） embedded in glass are analysed by means of absorption spectra, photoluminescence （PL） spectra and photoluminescence excitation （PLE） spectra. The peaks of absorption spectra shift to lower energies with the size of QD increasing, which obviously shows a quantum-size effect. Using the PLE spectra, the physical origin of the lowest absorption peak is analysed. In PLE spectra, the lowest absorption peak can be deconvoluted into two peaks that stem from the transitions of 1S3/2-1Se and 2S3/2-1Se respectively. The measured energy difference between the two peaks is found to decrease with the size of QD increasing, which agrees well with the theoretical calculation for the two transitions. The luminescence peak of defect states is also analysed by PLE spectra. Two transitions are present in the PLE, which indicates that the transitions of 1S3/2 1Se and 2S3/2 1Se are responsible for the defect states luminescence.
文摘A finite element model of vehicle and its airbag landing attenuation system is established and verified experimentally.Two design cases are selected to constrain the airbag design for extreme landing conditions,while the height and width of airbag and the area of vent hole are chosen as design variables.The optimization is forced to compromise the design variables between the conflicting requirements of the two extremes.In order to optimize the parameters of airbag,the multi-dimensional response surfaces based on extended Latin hypercube design and radial basis function are employed instead of the complex finite element model.Pareto optimal solution sets based on response surfaces are then obtained by multi-objective genetic algorithm.The results show the optimization method presented in this paper is a practical tool for the optimization of airbag landing attenuation system for heavy airdrop.
文摘The electric transmission system congfiguration-2 is one of the main electric drives for tracked vehicles. The geometrical model for the power-train cabin is established and the preliminary design for its cooling system is implemented. The mathematic model is established for thermal current field computation, simulation and analysis in the powertrain cabin. The three-dimensional structure of the powertrain cabin is optimized. The validity of the cooling system design is proved. The foundation for optimizing the whole electric transmission system configuration is laid.
文摘To predict the erosion and abrasion of high bore pressure tank gun barrel, the least square support vector machine (LSSVM) algorithm was used. Based on the gun firing test data, the prediction model for barrel's erosion and abrasion was established. It was adopted to predict the wear increment of gun barrel. The results show that the prediction values given by the model coincide with the measured data better, and the model can predict the barrel's wear accurately and rapidly.
基金supported by the National Basic Research Program of China (Grant No. 2010CB923202)
文摘The analytic surface plasmon polaritons （SPPs） dispersion relation is studied in a system consisting of a thin metallic film bounded by two sides media of nonlinear dielectric of arbitrary nonlinearity is studied by applying a generalised first integral approach. We consider both asymmetric and symmetric structures. Especially, in the symmetric system, two possible modes can exist： the odd mode and the even mode. The dispersion relations of the two modes are obtained. Due to the nonlinear dielectric, the magnitude of the electric field at the interface appears and alters the dispersion relations. The changes in SPPs dispersion relations depending on film thicknesses and nonlinearity are studied.
文摘The acoustic vibration signal of tank is disassembled into the sum of intrinsic mode function （IMF） by multi-resolution empirical mode decomposition （EMD） method. The instantaneous frequency is obtained, and feature transformation matrix is figured out by class scatter matrix. Multi- dimensional scale energy vector is mapped into low-dimensional eigenvector, and classification extraction is realized. This method sufficiently separates of different sound target features. The test result indicates that it is effective.
文摘Structures of two classes of solvable subgroups in SL（3, C） are given in this paper, and the integrability of the 3-order Fuchsian equation which is integrable in the sense that its monodromy group is solvable is discussed.
文摘Aimed at the requirements for electric transmission system of a military tracked vehicle, the motor's design indexes were analysed and calculated. A model based on saturate inductance parameter of interior permanent magnet (IPM) synchronous motor was brought forward by using finite element analysis. And its control strategy based on the largest running capability was studied also. The experiment results for a scale model show that the modelling method improves the model's accuracy, and the motor's control strategy is effective.
基金supported by the Open Foundation of Key Laboratory of Nondestructive Testing of Ministry of Education of Nanchang Aeronautical University
文摘A set of metallic specimens containing fatigue cracks with different sizes were tested using eddy current pulsed thermography(ECPT),therefore the relations between heating response of the crack area and the crack length was studied.The numerical and experimental results both showed that the increase of the crack length enhanced the crack heating response under specific test conditions.A particular form of calculated response signal,which is linearly related to the crack length,was introduced to provide a quantitative evaluation of crack length.
文摘A novel energy-regenerative active suspension(NEAS) system was designed to solve the problem of low energy recovery efficiency caused by frequent alternation of energy-recovery mode and active-control mode in a traditional energyregenerative active suspension(TEAS) system. The energy recovery and active control could be implemented simultaneously in the NEAS. The transforming processes and the corresponding computational formulas of power conversion in the NEAS were provided. The simulation results show that the performances of energy recovery of the NEAS are improved, and the selfsustaining of power supply for the NEAS can be realized.
文摘A computational fluid dynamics(CFD)calculation model for the airflow and heat transfer in an armored vehicle cooling wind tunnel is established.A practical method to determine computation region outside power train compartment,produce grid and ensure grid quality is put forward.A commercial software FLUENT can be used to obtain solutions numerically in 3-D space.Precision of CFD calculation results is verified.The CFD model is used in designing a vehicle cooling wind tunnel,and air flow resistance of fan blast baffle is calculated.The calculated results show feasibility of the CFD model and the method.
文摘Both the traverse subsystem and the elevation subsystem of the all-electrical tank gun control system are composed of electrical drive control system respectively. The parameters of PI regulator in these electrical drive control systems affect the performance of the control system seriously. Up to now, there is not a simple and practical method for choosing regulator parameters, which are usually determined by repeated and continual readjustment. This method is low efficient, and the parameters got are not always optimal. A method for on-line adjusting the parameters of PI regulator in the electrical drive control system by computer program is introduced in this paper. The function of adjusting PI parameters of the electrical drive control system is realized by PC program written by VC++ and controlling program written by assemble language and by the communication between PC and DSP completed by the control MSCOMM in VC++6.0. The method as mentioned above which is applied for an all-electrical tank gun control system under development is proved very available, a better performance might be obtained for the all-electrical tank gun control system easily.
文摘To know the temperature status of track and wheels on tank,the finite element calculation of temperature field was implemented with ANSYS software.The detailed temperature distributions for road wheel,drive wheel,idle wheel and track loop were obtained.The effect of factors,such as tank speed,environment temperature,sun radiant energy,ground deformation resistant and tank load,on the temperature of road wheel was studied.The sensitivity analysis shows that the effect of tank load on the temperature is the most,and the effect of ground deformation resistant is the least.The temperature testing device for road wheel on tank was developed to perform the experiments in real time.The calculated temperatures are in accord well with the experimental values.
基金the National Defence Sci-Tech Key Lab Fundation(51457040204BQ0102)
文摘Over recent years the progress in actuator and microelectronics technology has made intelligent suspension systems feasible.Based on conventional vane hydraulic damper,a new vane magneto-rheological fluid(MRF) damper with fail-safe capability is designed.Firstly,the mathematical model of damping moment is deduced based on the parallel-plate model and Bingham model of MR fluids.Secondly,some influence factors of damping adjustable multiple are analyzed to provide some ways for augmenting the damping adjustable multiple under the condition of keeping initial damping moment invariable.Finally,the magnetic circuit is designed,and magnetic field distribution is simulated with the magnetic finite element analysis software-ANSOFT.The theory and simulation results confirm that the damping adjustable range of vane MRF damper can meet the requirement of heavy vehicle semi-active suspension system.
