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RSS2014 Vol. 33, No. 6
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2014, 33(6): 789-791.
doi: 10.13433/j.cnki.1003-8728.2014.0601
PDF 369KB
Abstract:
Aiming to the lack of accurate theoretical analysis of spheric joint of working cylinder for double columntype forging hydraulic press, a mechanical model for spheric joint support is presented and the frictional resistingmoment of spheric joint support and the radius of friction circle is discussed to determine the double spheric jointand single shperic joint's lateral thrust to the moving parts. By elaborating the importance of spheric joint's rotationcondition and lateral thrust to the force analysis of working cylinder and analyzing the factors that influence thelateral thrust of spheric joint and the applicable scope of double spheric joint and single spheric joint sturctures, afurther research of the moving parts' rotation of double column type forging hydraulic press and the eccentricforging's function mechanism to the main working cylinder could be made.
Aiming to the lack of accurate theoretical analysis of spheric joint of working cylinder for double columntype forging hydraulic press, a mechanical model for spheric joint support is presented and the frictional resistingmoment of spheric joint support and the radius of friction circle is discussed to determine the double spheric jointand single shperic joint's lateral thrust to the moving parts. By elaborating the importance of spheric joint's rotationcondition and lateral thrust to the force analysis of working cylinder and analyzing the factors that influence thelateral thrust of spheric joint and the applicable scope of double spheric joint and single spheric joint sturctures, afurther research of the moving parts' rotation of double column type forging hydraulic press and the eccentricforging's function mechanism to the main working cylinder could be made.
2014, 33(6): 792-795.
doi: 10.13433/j.cnki.1003-8728.2014.0602
Abstract:
According to the analysis of mechanism of unbalanced magnetic pull(UMP), UMP was equivalent to thesupport element with“negative stiffness” during dynamics analysis of the motorized spindle. Based on the transfermatrix method, the dynamic model for high speed motorized spindle with the externally pressurized gas bearing wasconstructed by considering unbalanced magnetic pull. And taking high speed motorized spindle with the externallypressurized gas bearing as an object, Dynamics characteristic was calculated and simulated by using MATLAB7. 0software. The results showed that first three modes critical speed of motorized spindle considering unbalancedmagnetic pull was reduced to a certain degree, and the spindle speed was much higher than the first-mode criticalspeed, which belonged to the flexible spindle.
According to the analysis of mechanism of unbalanced magnetic pull(UMP), UMP was equivalent to thesupport element with“negative stiffness” during dynamics analysis of the motorized spindle. Based on the transfermatrix method, the dynamic model for high speed motorized spindle with the externally pressurized gas bearing wasconstructed by considering unbalanced magnetic pull. And taking high speed motorized spindle with the externallypressurized gas bearing as an object, Dynamics characteristic was calculated and simulated by using MATLAB7. 0software. The results showed that first three modes critical speed of motorized spindle considering unbalancedmagnetic pull was reduced to a certain degree, and the spindle speed was much higher than the first-mode criticalspeed, which belonged to the flexible spindle.
2014, 33(6): 796-801.
doi: 10.13433/j.cnki.1003-8728.2014.0603
Abstract:
The force analysis of a novel 4-SPS/CU parallel mechanism is investigated through statics vectorequilibrium equations. The equilibrium equations in which the equations' number is greater than the unknownvariables are formulated for this mechanism. It happens that the number of redundant equations is equal to the localdegrees of freedom, and redundant equations are abandoned by using the local switch matrix. Such preprocessingfor the local degrees of freedom can improve the efficiency of the solved statics equilibrium equations. In order tosystematically research the influence of the local degrees of freedom and over-constraint on the statics equilibriumequations, the relations between the solvability of statics equilibrium equations in the two to five orderoverconstrained mechanism and the local degrees of freedom, over-constraint are respectively discussed. Thejudgment method of the local degrees of freedom and over-constraint is established. It proves that the influences ofthe local degrees of freedom and over-constraint on the statics equilibrium equations are universal, which providesthe rationale for the solution of joint constraint forces.
The force analysis of a novel 4-SPS/CU parallel mechanism is investigated through statics vectorequilibrium equations. The equilibrium equations in which the equations' number is greater than the unknownvariables are formulated for this mechanism. It happens that the number of redundant equations is equal to the localdegrees of freedom, and redundant equations are abandoned by using the local switch matrix. Such preprocessingfor the local degrees of freedom can improve the efficiency of the solved statics equilibrium equations. In order tosystematically research the influence of the local degrees of freedom and over-constraint on the statics equilibriumequations, the relations between the solvability of statics equilibrium equations in the two to five orderoverconstrained mechanism and the local degrees of freedom, over-constraint are respectively discussed. Thejudgment method of the local degrees of freedom and over-constraint is established. It proves that the influences ofthe local degrees of freedom and over-constraint on the statics equilibrium equations are universal, which providesthe rationale for the solution of joint constraint forces.
2014, 33(6): 802-806.
doi: 10.13433/j.cnki.1003-8728.2014.0604
Abstract:
There was a typical disadvantage in the early developed biped walking mechanism that it could not walkstably by only one mechanism. Balance device and control strategies were applied on a new Biped-Imitating WalkingMechanism (BIWM) to overcome this shortcoming. On the basis of introducing the basic structure of BIWM and itswalking principle, the dynamic position of ZMP of BIWM during single-support phase and double-support phase wereanalyzed in details. The expected ZMP position, which enables BIWM to walk stably at any time, could be obtainedby the controlled movement of balance mass. The relative motion path and motion function of balance mass werepresented. Simulation case study was given to verify the availability of walking stability control for BIWM.
There was a typical disadvantage in the early developed biped walking mechanism that it could not walkstably by only one mechanism. Balance device and control strategies were applied on a new Biped-Imitating WalkingMechanism (BIWM) to overcome this shortcoming. On the basis of introducing the basic structure of BIWM and itswalking principle, the dynamic position of ZMP of BIWM during single-support phase and double-support phase wereanalyzed in details. The expected ZMP position, which enables BIWM to walk stably at any time, could be obtainedby the controlled movement of balance mass. The relative motion path and motion function of balance mass werepresented. Simulation case study was given to verify the availability of walking stability control for BIWM.
2014, 33(6): 807-810.
doi: 10.13433/j.cnki.1003-8728.2014.0605
Abstract:
The Ant Colony Optimization (ACO) algorithm with an improved pheromone updating rule wasintroduced in this paper, in which the binary coding was used to transfer the continuous variables to discretevariables. The improved ACO algorithm was applied to analysis and optimization of two classical truss structures,namely the ten-bar plane truss and the seventy two-bar space truss. The comparisons between improved ACO andother algorithms in the previous literatures show that for the ten-bar truss optimization, the optimum solutionobtained by improved ACO algorithm is closer to the optimum value than other algorithms, where the relativedeviation is about 0. 18%; for the seventy two-bar space truss optimization, the optimum design is better than thoseof other algorithms, where the relative deviation is about 2. 8%.
The Ant Colony Optimization (ACO) algorithm with an improved pheromone updating rule wasintroduced in this paper, in which the binary coding was used to transfer the continuous variables to discretevariables. The improved ACO algorithm was applied to analysis and optimization of two classical truss structures,namely the ten-bar plane truss and the seventy two-bar space truss. The comparisons between improved ACO andother algorithms in the previous literatures show that for the ten-bar truss optimization, the optimum solutionobtained by improved ACO algorithm is closer to the optimum value than other algorithms, where the relativedeviation is about 0. 18%; for the seventy two-bar space truss optimization, the optimum design is better than thoseof other algorithms, where the relative deviation is about 2. 8%.
2014, 33(6): 811-814.
doi: 10.13433/j.cnki.1003-8728.2014.0606
Abstract:
The paper presents a method of mechanism selection during mechanical design scheme on the basis ofextenics. The original and kernel models for the problem are built according to extension strategy generating.Several of strategies solving the contradiction are generated by extension analysis and extension transformation. Thestrategies are assessed by means of the excellent degree evaluation. The feasibility and effectiveness of the proposedmethod are verified by the selection of reciprocating motion mechanism for plane blade of planer.
The paper presents a method of mechanism selection during mechanical design scheme on the basis ofextenics. The original and kernel models for the problem are built according to extension strategy generating.Several of strategies solving the contradiction are generated by extension analysis and extension transformation. Thestrategies are assessed by means of the excellent degree evaluation. The feasibility and effectiveness of the proposedmethod are verified by the selection of reciprocating motion mechanism for plane blade of planer.
2014, 33(6): 815-819.
doi: 10.13433/j.cnki.1003-8728.2014.0607
Abstract:
The present research based on SIMPLE algorithm, and the numerical test used rNG k-ε turbulencemodel and dispersed control equations of flow field with the finite volume method. The test employed CFX moduleand the Static Structure module of ANSYS Workbench software to make fluid-structure coupling simulation. Throughthe simulation of full machine under the conditions of four wind speeds with considering the nacelle and tower, theflow field characteristics, the stress and strain of the structure in the operation process of wind turbine wereanalyzed, and compared with those without nacelle and tower. The results showed that the presence of the nacelleand tower had significant influence on the flow field characteristics; the pressure distribution of blades was obviousconcentrated on the tip position; the maximum stress of wind turbine concentrated on the blade where was abouttwo-thirds length from the blade root; with the increase of wind speed, the stress at the connection between bladeroot and wheel hub had a obvious increase.
The present research based on SIMPLE algorithm, and the numerical test used rNG k-ε turbulencemodel and dispersed control equations of flow field with the finite volume method. The test employed CFX moduleand the Static Structure module of ANSYS Workbench software to make fluid-structure coupling simulation. Throughthe simulation of full machine under the conditions of four wind speeds with considering the nacelle and tower, theflow field characteristics, the stress and strain of the structure in the operation process of wind turbine wereanalyzed, and compared with those without nacelle and tower. The results showed that the presence of the nacelleand tower had significant influence on the flow field characteristics; the pressure distribution of blades was obviousconcentrated on the tip position; the maximum stress of wind turbine concentrated on the blade where was abouttwo-thirds length from the blade root; with the increase of wind speed, the stress at the connection between bladeroot and wheel hub had a obvious increase.
2014, 33(6): 820-824.
doi: 10.13433/j.cnki.1003-8728.2014.0608
Abstract:
The research on robot inverse kinematics is the basis of robot controlling. Firstly, the screw theory andinverse kinematical product of exponentials (POE) were introduced. Then, based on the screw theory and inversekinematical POE, the inverse kinematical sub problems were analyzed. The inverse kinematical model of rrrProbot was built according to its characteristics. The whole inverse kinematical problem was divided into several subproblems, and joints angles equations were obtained under the giving position and pose of the end tool. Comparedwith the traditional D-H method, the whole process of the presented method showed the simpler and superiormeaning. The method provides a new approach for the analysis of similar kinematics and dynamics.
The research on robot inverse kinematics is the basis of robot controlling. Firstly, the screw theory andinverse kinematical product of exponentials (POE) were introduced. Then, based on the screw theory and inversekinematical POE, the inverse kinematical sub problems were analyzed. The inverse kinematical model of rrrProbot was built according to its characteristics. The whole inverse kinematical problem was divided into several subproblems, and joints angles equations were obtained under the giving position and pose of the end tool. Comparedwith the traditional D-H method, the whole process of the presented method showed the simpler and superiormeaning. The method provides a new approach for the analysis of similar kinematics and dynamics.
2014, 33(6): 825-828.
doi: 10.13433/j.cnki.1003-8728.2014.0609
Abstract:
Defect electromagnetic testing signals of steel cord conveyor belt in coal mine are vulnerable to beaffected by the non-stationary strong noise of working conditions in coal mine. In this paper, a kind of variable stepsize LMS adaptive filtering algorithm based on improved threshold wavelet was presented, which was used to filternon-stationary noise of defect signals of steel cord conveyor belt. First, in this method, the high frequency signalsfrom improved threshold wavelet multi-scale decomposition were used as reference noise signals of adaptivefiltering. Then, the defect signals were filtered by variable step size LMS adaptive filtering method. This methodcan overcome soft and hard threshold defects of the wavelet, and step size requirement inconsistent contradictionbetween convergence speed and steady-state error. This method was also compared with improved threshold waveletfiltering method. The results show that the method has better filtering effect, as well as it can effectively filter nonstationary strong noise in defect signals of steel cord conveyor belt.
Defect electromagnetic testing signals of steel cord conveyor belt in coal mine are vulnerable to beaffected by the non-stationary strong noise of working conditions in coal mine. In this paper, a kind of variable stepsize LMS adaptive filtering algorithm based on improved threshold wavelet was presented, which was used to filternon-stationary noise of defect signals of steel cord conveyor belt. First, in this method, the high frequency signalsfrom improved threshold wavelet multi-scale decomposition were used as reference noise signals of adaptivefiltering. Then, the defect signals were filtered by variable step size LMS adaptive filtering method. This methodcan overcome soft and hard threshold defects of the wavelet, and step size requirement inconsistent contradictionbetween convergence speed and steady-state error. This method was also compared with improved threshold waveletfiltering method. The results show that the method has better filtering effect, as well as it can effectively filter nonstationary strong noise in defect signals of steel cord conveyor belt.
2014, 33(6): 829-833.
doi: 10.13433/j.cnki.1003-8728.2014.0610
Abstract:
Based on the elastic contact theory, the elastic contact model for double-row angular ball bearings wasestablished, then the contact load between the ball and the inner raceway was calculated with Newton-raphsonmethod. The distributions of contact load and the variations of contact angle of the bearings under radial load, axialload and moment load were analyzed. The results show that the load distributions of the two rows of bearing are thesame under pure radial load; while only one row of bearing is loaded under pure central axial load. When theexternal moment load is considered the two row balls of bearing are loaded simultaneously, however, one row ballssupport heavier load than the other row balls; and the contact loads between the balls and the inner racewayincrease with the increasing of external load, but the contact angle is not directly related to their contact load.
Based on the elastic contact theory, the elastic contact model for double-row angular ball bearings wasestablished, then the contact load between the ball and the inner raceway was calculated with Newton-raphsonmethod. The distributions of contact load and the variations of contact angle of the bearings under radial load, axialload and moment load were analyzed. The results show that the load distributions of the two rows of bearing are thesame under pure radial load; while only one row of bearing is loaded under pure central axial load. When theexternal moment load is considered the two row balls of bearing are loaded simultaneously, however, one row ballssupport heavier load than the other row balls; and the contact loads between the balls and the inner racewayincrease with the increasing of external load, but the contact angle is not directly related to their contact load.
2014, 33(6): 834-839.
doi: 10.13433/j.cnki.1003-8728.2014.0611
Abstract:
Sliding bearing is one of the most important friction pairs in engine lubrication system. In this paper, acalculation model for lubrication analysis of dynamically loaded journal bearing was established using meshlessreproducing Kernel Particle Method (rKPM). The penalty method was used to impose the Dirichlet essentialboundary condition, and the discrete formulation of dynamic reynolds equation based on rKPM was deduced indetail. Meanwhile, the oil film pressure and nonlinear journal orbit were computed by integrating the motionequation of the journal with the dynamic reynolds equation. Finally, the effect of node number and nodedistribution on the computational accuracy of oil film pressure was discussed through numerical example andprograms, and the best value range of penalty factor was 1. 0 × 102～1. 0 × 104, and the errors estimation wasperformed. The results indicate that the lubrication calculation model based on rKPM has a higher accuracy nomatter uniform or random node distribution, and the computational accuracy increases with the node number.
Sliding bearing is one of the most important friction pairs in engine lubrication system. In this paper, acalculation model for lubrication analysis of dynamically loaded journal bearing was established using meshlessreproducing Kernel Particle Method (rKPM). The penalty method was used to impose the Dirichlet essentialboundary condition, and the discrete formulation of dynamic reynolds equation based on rKPM was deduced indetail. Meanwhile, the oil film pressure and nonlinear journal orbit were computed by integrating the motionequation of the journal with the dynamic reynolds equation. Finally, the effect of node number and nodedistribution on the computational accuracy of oil film pressure was discussed through numerical example andprograms, and the best value range of penalty factor was 1. 0 × 102～1. 0 × 104, and the errors estimation wasperformed. The results indicate that the lubrication calculation model based on rKPM has a higher accuracy nomatter uniform or random node distribution, and the computational accuracy increases with the node number.
2014, 33(6): 840-844.
doi: 10.13433/j.cnki.1003-8728.2014.0612
Abstract:
This paper has derived the expression of oil film thickness related to temperature by theoretical analysis. Thetwo-dimensional axisymmetric model of oil seal is also established. Considering the oil film thickness and thermoviscosity effect, the influence of shaft speed and circumferential load on the oil seal lip temperature distribution,maximum temperature and temperature-rise is analyzed. Furthermore, the influence of lip temperature on the oil seallubrication failure is also studied. The results show that the temperature gradient is large near the oil seal lip, thefrictional heat generated between oil seal and shaft is dissipated mainly by shaft and engine oil. The maximumtemperature and temperature-elevation of the oil seal lip increase with the increasing of shaft speed and circumferentialload. With the increase of oil seal lip temperature-elevation, the viscosity of engine oil and the oil film thicknessdecreases. Lubrication failure occurs in the oil seal as the oil film thickness is less than the critical value.
This paper has derived the expression of oil film thickness related to temperature by theoretical analysis. Thetwo-dimensional axisymmetric model of oil seal is also established. Considering the oil film thickness and thermoviscosity effect, the influence of shaft speed and circumferential load on the oil seal lip temperature distribution,maximum temperature and temperature-rise is analyzed. Furthermore, the influence of lip temperature on the oil seallubrication failure is also studied. The results show that the temperature gradient is large near the oil seal lip, thefrictional heat generated between oil seal and shaft is dissipated mainly by shaft and engine oil. The maximumtemperature and temperature-elevation of the oil seal lip increase with the increasing of shaft speed and circumferentialload. With the increase of oil seal lip temperature-elevation, the viscosity of engine oil and the oil film thicknessdecreases. Lubrication failure occurs in the oil seal as the oil film thickness is less than the critical value.
2014, 33(6): 845-848.
doi: 10.13433/j.cnki.1003-8728.2014.0613
Abstract:
Considered the heat generation and thermal boundary condition of the rotating ball bearing, a quasi-staticmodel of ball bearing was established to analyze the stress state of the bearing, and the frictional heat of the bearingwas calculated by the Palmgren empirical formula. Based on heat transfer theory, a heat transfer network model,which took the thermal resistances into account, was constructed for grease-lubricated bearing. A bearing-rotorsystem was developed to measure the temperature changes of bearing outer ring in various working conditions. Theexperimental results indicate that the proposed models can effectively predict the temperature rises of rotatinggrease-lubricated ball bearings and the prediction error is less than 10%; the temperature rises quickest in setupphase of bearings; and the rotating speed and preload of bearings must require reasonable control, which have a biginfluence on the steady temperature.
Considered the heat generation and thermal boundary condition of the rotating ball bearing, a quasi-staticmodel of ball bearing was established to analyze the stress state of the bearing, and the frictional heat of the bearingwas calculated by the Palmgren empirical formula. Based on heat transfer theory, a heat transfer network model,which took the thermal resistances into account, was constructed for grease-lubricated bearing. A bearing-rotorsystem was developed to measure the temperature changes of bearing outer ring in various working conditions. Theexperimental results indicate that the proposed models can effectively predict the temperature rises of rotatinggrease-lubricated ball bearings and the prediction error is less than 10%; the temperature rises quickest in setupphase of bearings; and the rotating speed and preload of bearings must require reasonable control, which have a biginfluence on the steady temperature.
2014, 33(6): 849-853.
doi: 10.13433/j.cnki.1003-8728.2014.0614
Abstract:
In the monitoring of cutting tool state, a large number of acoustic noise is contained in the sensor signal.Therefore, it is difficult to get the tool wear state, which is obviously not conducive to pattern recognition. Observedsignals were processed using the method of ensemble empirical mode decomposition based joint approximatediagonalization of eigenmatrice (J-EEMD). In this method, based on the characteristics of the signal itself, thesignals of vibration and acoustic emission were adaptively decomposed into several intrinsic mode functions (IMF);and then transform the energy ratio between the IMF and the original signals of vibrations and acoustic emission;finally the tool state characteristics under different wearing can be extracted. The test result showed that the methodcould preferably help in carrying out the pattern recognition to the different states of tool wear.
In the monitoring of cutting tool state, a large number of acoustic noise is contained in the sensor signal.Therefore, it is difficult to get the tool wear state, which is obviously not conducive to pattern recognition. Observedsignals were processed using the method of ensemble empirical mode decomposition based joint approximatediagonalization of eigenmatrice (J-EEMD). In this method, based on the characteristics of the signal itself, thesignals of vibration and acoustic emission were adaptively decomposed into several intrinsic mode functions (IMF);and then transform the energy ratio between the IMF and the original signals of vibrations and acoustic emission;finally the tool state characteristics under different wearing can be extracted. The test result showed that the methodcould preferably help in carrying out the pattern recognition to the different states of tool wear.
2014, 33(6): 854-857.
doi: 10.13433/j.cnki.1003-8728.2014.0615
Abstract:
Backlash has a great effect on the precision of the worm gearing transmission in heliostat, through theanalysis of the backlash; the transmission characteristic of the worm gearing can be evaluated. First, the constantbacklash and the variation backlash were gotten by means of the geometry method. Then, the equation of the circlebacklash was derived by using statistical analysis method in order to get a precise solution. Through calculatingheliostat of the precise worm gearing, it was proved that the present method was basically identical with answercomparing with the practical.
Backlash has a great effect on the precision of the worm gearing transmission in heliostat, through theanalysis of the backlash; the transmission characteristic of the worm gearing can be evaluated. First, the constantbacklash and the variation backlash were gotten by means of the geometry method. Then, the equation of the circlebacklash was derived by using statistical analysis method in order to get a precise solution. Through calculatingheliostat of the precise worm gearing, it was proved that the present method was basically identical with answercomparing with the practical.
2014, 33(6): 858-863.
doi: 10.13433/j.cnki.1003-8728.2014.0616
Abstract:
It will be able to get a better surface quality in the precision honing of the engine cylinder liner with thetechnology of power ultrasonic machining. The grinding force is related to the ultrasonic vibration, which affects thematerial removal, grinding heat and the surface quality. Based on the material removal mechanism of ultrasonichoning and the grain distribution on the surface of oilstone, the ultrasonic honing force model was established, whichincluded material chip deformation and friction situation between grain and workpiece. With the simulation resultsobtained by using the established force model it can be found that the grinding force is affected by the processingparameters and the physical change of materials; the ultrasonic honing force is decreased by more than 50%compared with the traditional honing under the same processing condition, and the ratio of normal force to tangentialforce is also increased; the average dynamic friction coefficient decreases under ultrasonic vibration, leading to thereducing of average tangential force; the honing depth is more significant to affect the honing force than the spindlespeed, and the honing force begin to decrease gradually when the spindle speed is higher than 620 r/min.
It will be able to get a better surface quality in the precision honing of the engine cylinder liner with thetechnology of power ultrasonic machining. The grinding force is related to the ultrasonic vibration, which affects thematerial removal, grinding heat and the surface quality. Based on the material removal mechanism of ultrasonichoning and the grain distribution on the surface of oilstone, the ultrasonic honing force model was established, whichincluded material chip deformation and friction situation between grain and workpiece. With the simulation resultsobtained by using the established force model it can be found that the grinding force is affected by the processingparameters and the physical change of materials; the ultrasonic honing force is decreased by more than 50%compared with the traditional honing under the same processing condition, and the ratio of normal force to tangentialforce is also increased; the average dynamic friction coefficient decreases under ultrasonic vibration, leading to thereducing of average tangential force; the honing depth is more significant to affect the honing force than the spindlespeed, and the honing force begin to decrease gradually when the spindle speed is higher than 620 r/min.
2014, 33(6): 864-869.
doi: 10.13433/j.cnki.1003-8728.2014.0617
Abstract:
A new approach of feature vector optimization for extracting the effective fault information was presentedusing Fisher linear distance. Firstly, the vibration signals were decomposed into the sub-bands with the waveletpacket transform, and the energy of which was used to construct the feature vectors. Then, the methods ofdifference and similarity optimization were applied to select the sub-bands which have greater Fisher distancebetween the different bearing statuses, and meantime has the minimal Fisher distance within the same bearingstatus. The fault identification applied the continuous hidden Markov models, which successfully identified normalstatus, ball fault, inner race fault and outer race fault in three kinds of fault severities, and the identificationaccuracy was greater than 94%. The result of compared experiments showed the identification accuracy of thepresented method was better than the reference method.
A new approach of feature vector optimization for extracting the effective fault information was presentedusing Fisher linear distance. Firstly, the vibration signals were decomposed into the sub-bands with the waveletpacket transform, and the energy of which was used to construct the feature vectors. Then, the methods ofdifference and similarity optimization were applied to select the sub-bands which have greater Fisher distancebetween the different bearing statuses, and meantime has the minimal Fisher distance within the same bearingstatus. The fault identification applied the continuous hidden Markov models, which successfully identified normalstatus, ball fault, inner race fault and outer race fault in three kinds of fault severities, and the identificationaccuracy was greater than 94%. The result of compared experiments showed the identification accuracy of thepresented method was better than the reference method.
2014, 33(6): 870-874.
doi: 10.13433/j.cnki.1003-8728.2014.0618
Abstract:
The three dimensional decomposition algorithms for the STL model is presented for the DecomposedInjection Sculpturing (DIS) hybrid rapid Prototyping. Based on the modified winged edge data structure, a STLmodel is decomposed into several sub-models by means of the extended boundary algorithms. Every sub-modelcomprises the same type facets or vertical facets. The blocked boundaries are distinguished from a sub-model basedon the edge-pair, and then the sub-model is split by the sweep planes constructed by the blocked boundaries. Inresult, all sub-models have no blocked facet when looking in the direction of Z axis. The example illustrates thatthe algorithms can effectively decompose the STL model for DIS.
The three dimensional decomposition algorithms for the STL model is presented for the DecomposedInjection Sculpturing (DIS) hybrid rapid Prototyping. Based on the modified winged edge data structure, a STLmodel is decomposed into several sub-models by means of the extended boundary algorithms. Every sub-modelcomprises the same type facets or vertical facets. The blocked boundaries are distinguished from a sub-model basedon the edge-pair, and then the sub-model is split by the sweep planes constructed by the blocked boundaries. Inresult, all sub-models have no blocked facet when looking in the direction of Z axis. The example illustrates thatthe algorithms can effectively decompose the STL model for DIS.
2014, 33(6): 875-880.
doi: 10.13433/j.cnki.1003-8728.2014.0619
Abstract:
Focusing on the multidegree reduction problem of C-B閦ier curves, a new method is presented, whichcan deal with approximating a C-B閦ier curve of degree n by using a C-B閦ier curve of degree m (m < n). Bymeans of optimization methods, the multidegree reduction approximation problem of C-B閦ier curves is changed toan optimization problem. Based on the niche genetic algorithm(NGA), the new control points of approximation CB閦ier curve of degree m can be confirmed by solving the optimization problem. In the degree reduction process,two cases are considered respectively. One is the case without constraints of endpoint interpolations; the other is thecase with constraints of endpoint interpolations. At the same time, some degree reduction examples are discussed,the errors of approximate degree reduction are given, and the degree reduction error bound is estimated.Experimental results illustrate that the proposed method has good degree reduction effects.
Focusing on the multidegree reduction problem of C-B閦ier curves, a new method is presented, whichcan deal with approximating a C-B閦ier curve of degree n by using a C-B閦ier curve of degree m (m < n). Bymeans of optimization methods, the multidegree reduction approximation problem of C-B閦ier curves is changed toan optimization problem. Based on the niche genetic algorithm(NGA), the new control points of approximation CB閦ier curve of degree m can be confirmed by solving the optimization problem. In the degree reduction process,two cases are considered respectively. One is the case without constraints of endpoint interpolations; the other is thecase with constraints of endpoint interpolations. At the same time, some degree reduction examples are discussed,the errors of approximate degree reduction are given, and the degree reduction error bound is estimated.Experimental results illustrate that the proposed method has good degree reduction effects.
2014, 33(6): 881-885.
doi: 10.13433/j.cnki.1003-8728.2014.0620
Abstract:
An approach for 3 D registration in augmented reality from single circle of image is proposed: Under theassumption of the intrinsic parameters of camera has been calibrated, predefined 2D plane coordinate system and asingle circle in object plane are used to achieve pose estimation. The rotation matrix is estimated according tovirtual points of intersection between absolute conic and circle; and the translation vector is calculated afterdetermining the centre of circle in image plane, then the 3 D registration of augmented reality is accomplished. Thepresent method is applied to the combination of virtual and reality object in product assembling process, theassembly guidance information is superimposed on product assembly video to guide customer to carry out assemblyoperation. Experiments on the comparison of PnP algorithm indicated that the present algorithm is correct andeffective. By using the gear assembling experiment of output shaft in reduction box, the assembling process in theenvironment of augmented reality assembly guidance is analyzed and described.
An approach for 3 D registration in augmented reality from single circle of image is proposed: Under theassumption of the intrinsic parameters of camera has been calibrated, predefined 2D plane coordinate system and asingle circle in object plane are used to achieve pose estimation. The rotation matrix is estimated according tovirtual points of intersection between absolute conic and circle; and the translation vector is calculated afterdetermining the centre of circle in image plane, then the 3 D registration of augmented reality is accomplished. Thepresent method is applied to the combination of virtual and reality object in product assembling process, theassembly guidance information is superimposed on product assembly video to guide customer to carry out assemblyoperation. Experiments on the comparison of PnP algorithm indicated that the present algorithm is correct andeffective. By using the gear assembling experiment of output shaft in reduction box, the assembling process in theenvironment of augmented reality assembly guidance is analyzed and described.
2014, 33(6): 886-893.
doi: 10.13433/j.cnki.1003-8728.2014.0621
Abstract:
Both competitive evaluations of Crs and diverse preferences for each competitive product provided bycustomers possess fuzziness, therefore, an approach for determining competitive evaluations matrices of Crs and anapproach for estimating reciprocal preference matrices based on triangular fuzzy number were proposed. Accordingto the competitive evaluations matrix of Crs and the reciprocal preference matrix based on triangular fuzzy numbercorresponding to each of the selected customer,, the fuzzy information was normalized and uniformed to build amulti-objective programming model, which aims at determining competitive importance ratings of Crs by using aprinciple of minimizing the total deviation, thus the competitive importance rating of each customer can beobtained. Furthermore, based on the integration of fuzzy competitive evaluations of Crs and the fuzzy reciprocalpreference for each competitive product, the additive weighted approach was employed to acquire comprehensivecompetitive importance ratings of Crs.
Both competitive evaluations of Crs and diverse preferences for each competitive product provided bycustomers possess fuzziness, therefore, an approach for determining competitive evaluations matrices of Crs and anapproach for estimating reciprocal preference matrices based on triangular fuzzy number were proposed. Accordingto the competitive evaluations matrix of Crs and the reciprocal preference matrix based on triangular fuzzy numbercorresponding to each of the selected customer,, the fuzzy information was normalized and uniformed to build amulti-objective programming model, which aims at determining competitive importance ratings of Crs by using aprinciple of minimizing the total deviation, thus the competitive importance rating of each customer can beobtained. Furthermore, based on the integration of fuzzy competitive evaluations of Crs and the fuzzy reciprocalpreference for each competitive product, the additive weighted approach was employed to acquire comprehensivecompetitive importance ratings of Crs.
2014, 33(6): 894-900.
doi: 10.13433/j.cnki.1003-8728.2014.0622
Abstract:
Small axial flow fan is an important device for heat dissipation of computer CPU, etc. To improve itsaerodynamics and acoustics performance, a new improved structure was put forward. For the prototype and theimproved type, rNG k-ε turbulence model was applied to simulate the steady flow field, and the staticcharacteristics are calculated. Then regarding the steady flow field as the initial solutions, the noise was calculatedfor the monitoring points at the fan inlets, outlets and inners by using the unsteady large eddy simulation modeltogether with the FH-W acoustic model and Fourier transform. And the experimental investigations on the staticcharacteristics and the noise were also carried out. The results indicates that the improved structure has better effecton the static characteristics and noise abatement, and can be applied in production practice.
Small axial flow fan is an important device for heat dissipation of computer CPU, etc. To improve itsaerodynamics and acoustics performance, a new improved structure was put forward. For the prototype and theimproved type, rNG k-ε turbulence model was applied to simulate the steady flow field, and the staticcharacteristics are calculated. Then regarding the steady flow field as the initial solutions, the noise was calculatedfor the monitoring points at the fan inlets, outlets and inners by using the unsteady large eddy simulation modeltogether with the FH-W acoustic model and Fourier transform. And the experimental investigations on the staticcharacteristics and the noise were also carried out. The results indicates that the improved structure has better effecton the static characteristics and noise abatement, and can be applied in production practice.
2014, 33(6): 901-904.
doi: 10.13433/j.cnki.1003-8728.2014.0623
Abstract:
The researches on shock pulse nozzle mainly focus on the single cavity dynamic characteristics at homeand abroad, and the studies on its structure parameters are less. The work principle of the self excited pulse nozzleand the mechanism of its self-excited oscillation are analyzed in this paper, and the mathematical model of the selfexcited nozzle is established. Using the Fluent software, the different structure parameters of pulse jet nozzlecharacteristic are studied. Through the simulation analysis, the optimal structural parameters of self excited pulsenozzle are obtained. The results show that upper and lower nozzle diameter and cavity diameter have significantinfluence on the frequency, amplitude and the peak value of flow velocity. Due to the obstacles induced by vortexand cavitation on the inlet velocity and the difference of gas volume fraction, the flow velocity of inlet is bigger thanthat of the outlet.
The researches on shock pulse nozzle mainly focus on the single cavity dynamic characteristics at homeand abroad, and the studies on its structure parameters are less. The work principle of the self excited pulse nozzleand the mechanism of its self-excited oscillation are analyzed in this paper, and the mathematical model of the selfexcited nozzle is established. Using the Fluent software, the different structure parameters of pulse jet nozzlecharacteristic are studied. Through the simulation analysis, the optimal structural parameters of self excited pulsenozzle are obtained. The results show that upper and lower nozzle diameter and cavity diameter have significantinfluence on the frequency, amplitude and the peak value of flow velocity. Due to the obstacles induced by vortexand cavitation on the inlet velocity and the difference of gas volume fraction, the flow velocity of inlet is bigger thanthat of the outlet.
2014, 33(6): 905-908.
doi: 10.13433/j.cnki.1003-8728.2014.0624
Abstract:
The quantitative risk analysis and performance indicator evaluation of equipment are facing the lack ofreliability and maintenance data to carry out failure probability analysis. There is a limitation in using domestic andforeign database to evaluate the equipment in related process units. In order to improve the risk management andmaintenance decision-making level, an equipment quantitative risk analysis data acquisition and maintenancedecision-making system is developed to assess the risks, predict the residual working life and optimize themaintenance tasks. The practice shows that the established system can collect reliability and maintenance dataaccurately, quantify risk analysis and optimize maintenance tasks, and it has improved the reliability, availabilityand safety of equipments
The quantitative risk analysis and performance indicator evaluation of equipment are facing the lack ofreliability and maintenance data to carry out failure probability analysis. There is a limitation in using domestic andforeign database to evaluate the equipment in related process units. In order to improve the risk management andmaintenance decision-making level, an equipment quantitative risk analysis data acquisition and maintenancedecision-making system is developed to assess the risks, predict the residual working life and optimize themaintenance tasks. The practice shows that the established system can collect reliability and maintenance dataaccurately, quantify risk analysis and optimize maintenance tasks, and it has improved the reliability, availabilityand safety of equipments
2014, 33(6): 909-912.
doi: 10.13433/j.cnki.1003-8728.2014.0625
Abstract:
The measuring principle of the resistance stain gauge sensor is that elastic body is deformed by themeasured force, and then the resistance of strain gauges in principal strain direction is changed. Dual-E elasticbody six-axis force sensor can measure the force and moment information in six directions in the space by using thestructure of composite beam. But there are a large number of noises mixed in the output signal, such as thermalnoise of resistance strain gauges, the noise of electromagnetic device in amplifier circuit and the interference of hightemperature generated by the elastic body creep. The measurement accuracy of the sensor must be affected by thenoise signal. In order to effectively filter out measurement noise and improve sensor resolution, this paper selectsthe sensor' s rectangular beam as the research object. First, the system measurement equation based on therelationship between the response of sinusoidal excitation force and the strain has been established, and then thewhitening filtering of colored system interference based on time series analysis method has been designed, the statespace model of colored noise has been established, and finally the Kalman filtering formulas of colored noise havebeen derived. The simulation results indicate that this algorithm is effective, which has the high filtering accuracy,strong stability and reduces the error of actual filtering.
The measuring principle of the resistance stain gauge sensor is that elastic body is deformed by themeasured force, and then the resistance of strain gauges in principal strain direction is changed. Dual-E elasticbody six-axis force sensor can measure the force and moment information in six directions in the space by using thestructure of composite beam. But there are a large number of noises mixed in the output signal, such as thermalnoise of resistance strain gauges, the noise of electromagnetic device in amplifier circuit and the interference of hightemperature generated by the elastic body creep. The measurement accuracy of the sensor must be affected by thenoise signal. In order to effectively filter out measurement noise and improve sensor resolution, this paper selectsthe sensor' s rectangular beam as the research object. First, the system measurement equation based on therelationship between the response of sinusoidal excitation force and the strain has been established, and then thewhitening filtering of colored system interference based on time series analysis method has been designed, the statespace model of colored noise has been established, and finally the Kalman filtering formulas of colored noise havebeen derived. The simulation results indicate that this algorithm is effective, which has the high filtering accuracy,strong stability and reduces the error of actual filtering.
2014, 33(6): 913-917.
doi: 10.13433/j.cnki.1003-8728.2014.0626
Abstract:
Facing-forward simulation model is necessary during the process of vehicle design, in considering of therapid development of hybrid SUV, in the paper, a facing-forward simulation model for 4WD(4 wheel drive) hybridvehicle is established by secondary development of the Advisor software. The main control module of the simulationmodel includes a driver model, which contains a PI control module and the demand prediction module of vehiclelongitudinal force. The braking force distribution strategy and energy distribution strategy are also integrated into themain control module to simplify the top model. Basic theory of ASr(Acceleration Slip regulation) and reasonabledistribution of longitudinal force between front wheel and rear wheel are considered in the 4WD wheel module tosimulate torque distribution. The established facing-forward 4WD simulation model is applied in the analysis of ahybrid SUV with a virtual working condition, the result shows the established model is valid in facing-forwardsimulation.
Facing-forward simulation model is necessary during the process of vehicle design, in considering of therapid development of hybrid SUV, in the paper, a facing-forward simulation model for 4WD(4 wheel drive) hybridvehicle is established by secondary development of the Advisor software. The main control module of the simulationmodel includes a driver model, which contains a PI control module and the demand prediction module of vehiclelongitudinal force. The braking force distribution strategy and energy distribution strategy are also integrated into themain control module to simplify the top model. Basic theory of ASr(Acceleration Slip regulation) and reasonabledistribution of longitudinal force between front wheel and rear wheel are considered in the 4WD wheel module tosimulate torque distribution. The established facing-forward 4WD simulation model is applied in the analysis of ahybrid SUV with a virtual working condition, the result shows the established model is valid in facing-forwardsimulation.
2014, 33(6): 918-923.
doi: 10.13433/j.cnki.1003-8728.2014.0627
Abstract:
In view of bearings' greater impact on suspension and vehicle performances, selecting a rubber-steelbearing of one car' s torsion beam rear suspension as a research object, Yeoh polynomial was determined as thebearing's constitutive model by deriving from a strain energy density function. The bearing's structure test was doneto get some incomplete information of‘displacement-force' history test curves in X/Y/Z axial, the initial test wassimulated to get ‘displacement-force ' history simulation curves in X/Y/Z axial by using HyperStudy andABAQUS, the simulation curves were compared with the test curves to evaluate consistency between them. Themulti-parameters C10, C20, C30、Di of Yeoh polynomial were set as optimization variables and their initial values weregiven, 6 types of optimization objective functions were designated to ‘square of area difference' or ‘square ofdisplacement difference' equaling to zero, 14 interactive processes were performed by using the adaptive responsesurface (ArS) method, then the total weight value of 6 types of optimization objective functions converged andapproached to zero, and a set of values of the multi-parameters, which can more accurately simulate the bearing'smechanical behavior, were identified. The bearing' s test was simulated again; the results show that the fittingprecision is high between test and simulation curves in Y axial. Because of pre-tightening simulation and meshdivergence etc., the fitting precision is relative low between them in X and Z axial, but both of the error oftransient stiffness values is all less than 8%. If the average error is considered, this is can be accepted inengineering.
In view of bearings' greater impact on suspension and vehicle performances, selecting a rubber-steelbearing of one car' s torsion beam rear suspension as a research object, Yeoh polynomial was determined as thebearing's constitutive model by deriving from a strain energy density function. The bearing's structure test was doneto get some incomplete information of‘displacement-force' history test curves in X/Y/Z axial, the initial test wassimulated to get ‘displacement-force ' history simulation curves in X/Y/Z axial by using HyperStudy andABAQUS, the simulation curves were compared with the test curves to evaluate consistency between them. Themulti-parameters C10, C20, C30、Di of Yeoh polynomial were set as optimization variables and their initial values weregiven, 6 types of optimization objective functions were designated to ‘square of area difference' or ‘square ofdisplacement difference' equaling to zero, 14 interactive processes were performed by using the adaptive responsesurface (ArS) method, then the total weight value of 6 types of optimization objective functions converged andapproached to zero, and a set of values of the multi-parameters, which can more accurately simulate the bearing'smechanical behavior, were identified. The bearing' s test was simulated again; the results show that the fittingprecision is high between test and simulation curves in Y axial. Because of pre-tightening simulation and meshdivergence etc., the fitting precision is relative low between them in X and Z axial, but both of the error oftransient stiffness values is all less than 8%. If the average error is considered, this is can be accepted inengineering.
2014, 33(6): 924-928.
doi: 10.13433/j.cnki.1003-8728.2014.0628
Abstract:
The creep deformation of plastic guide wheel in auto glass lifter is investigated in this paper. Based onthe material creep tensile testing curve and the modified time hardening creep equation, the finite element model ofguide wheel creep analysis is established considering the contact effect of rope and wheel. Though numericalcomputation, the time history curves and their variation laws of strain, displacement at the guiding wheel keypositions are obtained, and these well agree with the test results. Analysis results both considering the contact effectof creep process and not considering the contact condition of creep process are compared. The results show that thecalculation results considering the contact creep analysis has relatively high precision and can reflect thedeformation and the stress of the guide wheel change process.
The creep deformation of plastic guide wheel in auto glass lifter is investigated in this paper. Based onthe material creep tensile testing curve and the modified time hardening creep equation, the finite element model ofguide wheel creep analysis is established considering the contact effect of rope and wheel. Though numericalcomputation, the time history curves and their variation laws of strain, displacement at the guiding wheel keypositions are obtained, and these well agree with the test results. Analysis results both considering the contact effectof creep process and not considering the contact condition of creep process are compared. The results show that thecalculation results considering the contact creep analysis has relatively high precision and can reflect thedeformation and the stress of the guide wheel change process.
2014, 33(6): 929-933.
doi: 10.13433/j.cnki.1003-8728.2014.0629
Abstract:
In view of powertrain parameter matching of an extended-range electric vehicle, the parameter matchingdesign of the powertrain was discussed based on the specifications of vehicle performance and driving range. Theparameters of the motor are determined by the accelerating performance, the grade ability and the maximum vehiclevelocity. reasonable matching of the driving characteristics both the motor and vehicle was reached. A fixed gearratio transmission is adopted, and the transmission ratio was optimized aimed to improve the energy efficiency. Theparameters of the battery and range extender are determined by driving range and power requirement. Through theco-simulation of Matlab/Simulink and Advisor, the power performance of vehicle was simulated in the NEDC (NewEuropean Driving Cycle). The simulation results indicate that the powertrain scheme and its parameter matchingare reasonable, and the power performance and driving range can meet the design requirements.
In view of powertrain parameter matching of an extended-range electric vehicle, the parameter matchingdesign of the powertrain was discussed based on the specifications of vehicle performance and driving range. Theparameters of the motor are determined by the accelerating performance, the grade ability and the maximum vehiclevelocity. reasonable matching of the driving characteristics both the motor and vehicle was reached. A fixed gearratio transmission is adopted, and the transmission ratio was optimized aimed to improve the energy efficiency. Theparameters of the battery and range extender are determined by driving range and power requirement. Through theco-simulation of Matlab/Simulink and Advisor, the power performance of vehicle was simulated in the NEDC (NewEuropean Driving Cycle). The simulation results indicate that the powertrain scheme and its parameter matchingare reasonable, and the power performance and driving range can meet the design requirements.
2014, 33(6): 934-938.
doi: 10.13433/j.cnki.1003-8728.2014.0630
Abstract:
his paper compares the mechanical properties of 2024 aluminum alloy in three states, the resultconfirms that the 2024-W aluminum alloy is one of the best for the sheet metal forming, and produces a part usingthis aged 2024-W aluminum alloy. After forming, the bottom of the part is not flat. To explain this phenomena, theprocess of fluid cell forming (Flexforming) is simulated by using the software Pam-stamp. The result shows that thematerials' compressive buckling is caused by inhomogeneous deformation with most regions in elastic state andthereby the residual stress distribution is inhomogeneous also.
his paper compares the mechanical properties of 2024 aluminum alloy in three states, the resultconfirms that the 2024-W aluminum alloy is one of the best for the sheet metal forming, and produces a part usingthis aged 2024-W aluminum alloy. After forming, the bottom of the part is not flat. To explain this phenomena, theprocess of fluid cell forming (Flexforming) is simulated by using the software Pam-stamp. The result shows that thematerials' compressive buckling is caused by inhomogeneous deformation with most regions in elastic state andthereby the residual stress distribution is inhomogeneous also.
2014, 33(6): 939-943.
doi: 10.13433/j.cnki.1003-8728.2014.0631
Abstract:
Generally, the forming limit diagram is used to predict the sheet neck and fracture in the conventionalforming process. The phenomenon that for forming the parts via Incremental sheet forming (ISF), the forming limitis much higher than that via conventional sheet forming has aroused a research interest in forming mechanism oflocal forming process in recent years. In this paper, the geometrical imperfection in the thickness was considered torepresent local weakening zone and by using the BAMMAN _ DAMAGE material model and assuming geometricimperfection method separately to study the effect of the non-homogenization on the sheet forming limit. The causeand mechanism for improving of forming limit during the incremental forming process was studied by the numericalsimulation method. And the variations of stress and strain during the forming process were also studied.
Generally, the forming limit diagram is used to predict the sheet neck and fracture in the conventionalforming process. The phenomenon that for forming the parts via Incremental sheet forming (ISF), the forming limitis much higher than that via conventional sheet forming has aroused a research interest in forming mechanism oflocal forming process in recent years. In this paper, the geometrical imperfection in the thickness was considered torepresent local weakening zone and by using the BAMMAN _ DAMAGE material model and assuming geometricimperfection method separately to study the effect of the non-homogenization on the sheet forming limit. The causeand mechanism for improving of forming limit during the incremental forming process was studied by the numericalsimulation method. And the variations of stress and strain during the forming process were also studied.
2014, 33(6): 944-947.
doi: 10.13433/j.cnki.1003-8728.2014.0632
Abstract:
To solve the problems in testing the bus information stream of the union avionics system which is used forground simulation experiment, a display and control simulator device based on the parallel theory is designed. The multi-rT(remote Terminal) simulation technology is adopted and a logical process including four display and controlsubsystem(AAP(Avionics Activation Panel) 、HUD(Head up Display) 、MFD(Multi Function Display) and UFCP(UpFront Control Panel)) is simulated in one PC. The display part and the control part, which are separated by thesimulator, connected to each other by a specific interface file via Ethernet and receive fault simulation data from it. Atlast, a ground simulation experiment validates that the present device has a good capability in engineering applications.
To solve the problems in testing the bus information stream of the union avionics system which is used forground simulation experiment, a display and control simulator device based on the parallel theory is designed. The multi-rT(remote Terminal) simulation technology is adopted and a logical process including four display and controlsubsystem(AAP(Avionics Activation Panel) 、HUD(Head up Display) 、MFD(Multi Function Display) and UFCP(UpFront Control Panel)) is simulated in one PC. The display part and the control part, which are separated by thesimulator, connected to each other by a specific interface file via Ethernet and receive fault simulation data from it. Atlast, a ground simulation experiment validates that the present device has a good capability in engineering applications.
2014, 33(6): 948-952.
doi: 10.13433/j.cnki.1003-8728.2014.0633
Abstract:
In order to select the aircraft waved beams structure with optimal energy absorption, the simulationanalysis for quasi-static loading tests and dynamic impact tests were conducted by using finite element code LSDYNA on four kinds of metal waved beams structures, including square waved beam, triangle waved beam, sinewaved beam and trapezoidal waved beam. The deformation modes and energy-absorbing characteristics of fourwaved beams structures were analyzed. The results show that the sine waved beams and trapezoidal waved beamscan maintain good shapes. Specific energy absorption (SEA) of sine waved beam is the maximal, while its originalpeak load (Pcr) and average load (Fm) are the minimal. The research results show that the sine waved beams canbe selected as the energy-absorbing structures of the fuselage sub-floor because of the optimal energy absorptioncharacteristics and cushioning effects.
In order to select the aircraft waved beams structure with optimal energy absorption, the simulationanalysis for quasi-static loading tests and dynamic impact tests were conducted by using finite element code LSDYNA on four kinds of metal waved beams structures, including square waved beam, triangle waved beam, sinewaved beam and trapezoidal waved beam. The deformation modes and energy-absorbing characteristics of fourwaved beams structures were analyzed. The results show that the sine waved beams and trapezoidal waved beamscan maintain good shapes. Specific energy absorption (SEA) of sine waved beam is the maximal, while its originalpeak load (Pcr) and average load (Fm) are the minimal. The research results show that the sine waved beams canbe selected as the energy-absorbing structures of the fuselage sub-floor because of the optimal energy absorptioncharacteristics and cushioning effects.
