最新刊期
期 2 ， 2016
- 摘要：In order to extract fault feature of signal. An improved blind deconvolution algorithm which based on generalized morphological filtering and improved KL distance clustering methods was proposed to deal with industrial field noise,multi interference sources and disadvantage of blind extraction algorithm. First,the generalized morphological filter was used to extract the characteristic signal of observation signal. Then,the orthogonal matching pursuit algorithm was used to remove the period component of signal after being filtered. Finally,the improved KL distance was used to calculate distance of each component and obtain the separated signal by fuzzy C cluster. The results of computer simulation and real rolling bearing signals analysis show that this proposed method is quite effective.关键词：Generalized morphological filtering;Compressed sensing;Improved KL distance;Blind signal processing
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发布时间：2022-09-22 - 摘要：Based on the misalignment of the high shaft,the paper puts forward an improved algorithm about the exciting force and torque generated by the coupling misalignment,which is under the influence of gyroscopic effect and inertial forces.Through the centralized mass method,the rotor system is simplified as a multi-disc system. According to the force balance and the coordination deformation motion system the establishment of the rotor of the differential equations,obtained exciting force and torque. N rotor systems are calculated the exciting force and torque caused by coupling misalignment via using the improved algorithm. According to the principles of probability and statistics,its characterization value can be got. Taking a high-speed flywheel housing for example,as a load is applied in a limited element dynamic simulation model carried harmonic response simulation,vibration test results with comparative analysis of the test results,which have been well validated,with a certain sense of engineering applications.关键词：Rotor misalignment;Gyroscopic effect;Disturbance force;Excitation moment
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发布时间：2022-09-22 - 摘要：Luffing system is an important part of fire ladder trucks,and plays a decisive role on the working stability.Aiming at the existing problems of fire ladder trucks in luffing conditions,researched on the dynamic characteristics of the main balancing valve,and drew the conclusion that balancing valve is the main cause of hydraulic fluctuations in luffing process,based on this,used AMESim to optimize the design of the structure of the balancing valve,selected the appropriate size of the orifice diameter. The simulation results showed that the hydraulic fluctuations in the luffing system had been effectively improved after the optimization,and achieved the desired aims. The solution will be reference for similar applying.关键词：Fire ladder trucks;Luffing system;Dynamic characteristics;AMEsim
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发布时间：2022-09-22 - 摘要：Aiming at the fact that the vibration signal of hydraulic pump would exactly display non-stationary characteristics and fault features hard to extracted,a feature extraction method of hydraulic pump based on LCD（ local characteristic-scale decomposition） fuzzy entropy and manifold learning was proposed. The proposed method combined the LCD,fuzzy entropy and manifold learning. Firstly,the vibration signals was decomposed into several ISCs（ intrinsic scale component） and fuzzy entropy of each ISC was calculated,and the high-dimension fault feature was preliminarily extracted. Secondly,LLTSA（ liner local tangent space alignment） which is one of typical manifold learning methods was applied to compress the high-dimension features into low-dimension features which have better discrimination. Finally,the SVM（ support vector machine） was employed to evaluate the feature extraction method. Experiment results of hydraulic pump show that the proposed method can classify different fault type of hydraulic pump exactly and has certain superiority.关键词：Local characteristic-scale Decomposition;Fuzzy entropy;Manifold learning;Feature extraction;Hydraulic pump
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发布时间：2022-09-22 - 摘要：This paper aims to propose a cylindrical magnetorheological fluid brake controlled by shape memory alloy,based on the shape memory effect of shape memory alloy under thermal effect and the rheological behavior of magnetorheological fluid.The shape memory alloy can be used to control the current that induces magnetic field. The Bingham model is used to describe the constitutive characteristics of magnetorheological fluid subject to an applied magnetic field to derive the braking torque equation of cylindrical magnetorheological fluid brake. The expression of the braking time can be obtained from the torqueequilibrium equation of the braked shaft. The relationships of the shape memory alloy switch ’s output displacement with the temperature,the size parameters,the material parameters and the operating load are established based on the shape memory effect. The results indicate that the output displacement of the shape memory alloy switch can change rapidly with the temperature. With the increase of the applied magnetic field strength,the braking torque developed by magnetorheological fluids goes up rapidly,and the braking time is shortened.关键词：Shape memory alloy switch;Magnetorheological fluid brake;Braking torque;Braking time
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发布时间：2022-09-22 - 摘要：The inherent characteristics of the high speed shaft and the unbalance response of the high speed shaft seriously affect the operating condition and service life of the high speed gearbox. For the high speed gear shaft,a multi distribution model of the system is established. The natural frequency and the unbalance response of the shaft are analyzed by using the transfer matrix method. The unbalance response of the shaft at different speeds and different eccentric quality is obtained with the same method. The unbalance response of the gear meshing point is investigated through the analysis of the unbalanced response characteristics in various cases,and the working conditions of the gear meshing point are analyzed,and the basis for the design and manufacture of high speed gear box is provided.关键词：High speed gear shaft;The rotors-support system;The natural frequency;Unbalanced response
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发布时间：2022-09-22 - 摘要：The Local characteristic-scale decomposition（ LCD） method is improved in this paper. The reason of appearance of the stagnation point on low frequency intrinsic scale component（ ISC） is analyzed and a new method which called eliminate stagnation point-based Local characteristic-scale decomposition method is presented. The results from the simulation signal have shown the obvious advantages of the improved LCD method. Based on the improvement of the LCD,the combination of the LCD and envelope analysis is applied to the roller bearing fault diagnosis. The roller bearing vibration signals is composed by the improved LCD into some intrinsic scale component（ ISC）. The envelope analysis method based on Hilbert is used to analyze the ISCs and the work state of rolling bearing can be identified. The experimental results showed that the improved LCD method and Envelopment analysis method have a good result to apply to the rolling bearing fault diagnosis.关键词：Local characteristic-scale;Decomposition;Envelopment analysis;Stagnation point;Roller bearing;Fault diagnosis
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发布时间：2022-09-22 - 摘要：Wave function expansion method and vibration theory are employed to study the out-of-plane response problem of the double degree of freedom vibration system installed on the half circular rigid platform on the half space boundary. The total displacement in the half space media was given using elastic wave theory,and the second order constant coefficient differential equations with which the double degree of freedom oscillatory system can also be given with the vibration theory,the unknown coefficients in the scattering functions can be obtained using the displacement and stress continuity conditions on the interface between the media and the rigid platform. And the variations of the relative displacement amplitude ratios of the rigid platform and the vibrators and the tangential stress concentration factor on the half circular interface can be given,the numerical results of given example show the correctness of the conclusions in the paper.关键词：Half-space;Double degree of freedom oscillatory system;Wave function expansion method;Displacement amplitude ratio;Stress concentration coefficient
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发布时间：2022-09-22 - 摘要：The flexible hinges in the compliant mechanism,when the cyclic loading with continuous and variable loads,are easily to induce the fatigue crack initiation in its thinnest place due to stress concentration. It ultimately causes fatigue failure in the flexible hinges. Using the elliptical hinge as the research object,this paper analyzed the characteristics of the maximum applied stress in the thinnest place of flexible hinges by using Taguchi Method. Orthogonal experiments were performed upon finding out the controllable factors and noise factors affecting the maximum stress. Sensitivity analysis based on Orthogonal experiments was applied loading to quantitatively analyze the effect of each design variable parameter on the maximum stress. The calculation showed that the change of the maximum stress depends on several design variables parameters,and the geometric parameter plays an important role. This method does not depend on optimization algorithm,can be employed for sensitivity analysis of discrete,non-differential or implicit-expression structures,and provides favorable reference to the robust design of the flexible hinges by improving its fatigue life.关键词：Flexible hinges;Stress concentration;Fatigue life;Taguchi method;Sensitivity
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发布时间：2022-09-22 - 摘要：The sliding bearing is an important component of propulsion shaft in ship; its stability is the basic promise of maneuverability. A large-sized sliding bearing on board as the subject was investigated. The experimental shafting system for simulating installation state and wording state on board was specially developed. The shock tests were carried through on floating shock platform subjected to underwater explosions. The test results showed that the rubs appeared between the bushing and shaft during intense vertical impact loading,as a result the operate moment of torque was instantly increased about 200%,which presented more requirements for shafting power. Due to the smaller intensity of transverse shock loading,the vibration amplitude was under the scope of bearing gap. Through these shock tests of sliding bearing,the dynamic model of oil film in present application does not appropriate for shock response analysis. This research presents reference for modifying shock dynamic model and increasing the simulation accuracy of shafting system.关键词：Sliding bearing;Underwater explosion;Shock test;Rub;Oil film force
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发布时间：2022-09-22 - 摘要：A gradient-less parametrical approach has been employed to optimize the stress concentration on local part. The design boundary was represented by splines and the shape of boundary can be varied by adjusting the coordinate of control points.By doing so to varying the stress distribution on design boundary. The average stress on design boundary was selected as the reference stress. Control points with higher stress than average stress move outward to add material; meanwhile,control points with lower stress move inward to reduce material to fulfill the shape optimization. Two feasible zones and three start shapes have been employed in optimization instances to compare the influence of the different feasible zones and start shapes,respectively.The influence of the control parameters to the optimization process and result have also been studied.关键词：Shape optimization;Stress concentration;Gradient-less;Finite element method
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发布时间：2022-09-22 - 摘要：The comprehensive performance of cutting mechanism of roadheader is decided by cutting dust,quantity of pick consumption,specific density consumption,load fluctuation and production efficiency. This paper takes motion parameters and structure parameters of cutting mechanism for design variables and optimizes multi-objective function of comprehensive performance of cutting mechanism based on the improved genetic algorithm. Optimization results show that cutting dust,quantity of pick consumption,specific density consumption and load fluctuation of roadheader are decreased accordingly and productivity is increased significantly,which effectively improve the whole performance of the machine and accord with development trend of the roadheader in line with the current and future.关键词：Cutting mechanism of roadheader;Improved genetic algorithm;Multi-objective function;Optimization design
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发布时间：2022-09-22 - 摘要：Improving design formula is an important way of increase design formula accuracy. The mean value and the coefficient of variation are the foundation of analysis formulas accuracy. Accuracy analysis and comparison of the same design formula applied in different ranges or different design formulas applied in the same or different ranges is an important part of evaluating design formula improvement effect. Establishing evaluation index and method of design formula improvement effect is an important basis in selecting and determining the design formula. Using strength-load interference model,reliability evaluation index and method were established that comparison single layer thick-walled cylinder burst strength design formulas improvement effect. In same or different ranges of application,the improvement effect of four burst strength design formulas for single layer thick-walled cylinder is analyzed and compared,the results can be reference for engineers in selecting and determining the design formula.关键词：Single layer thick-walled;Internal pressure cylinder;Burst strength;Design formula;Improve effect;Reliability analysis;Evaluation index
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发布时间：2022-09-22 - 摘要：The complete-data likelihood function of generalized exponential distribution for truncated and censored data is obtained by filling in the missing data of the life variable using rejection method. All the parameters are sampled by MCMC method of Gibbs sampling together with random-walk Metropolis algorithm. The means of Gibbs samples are taken as the estimations of the parameters. The random simulation test results show that the estimations are fairly accurate.
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发布时间：2022-09-22 - 摘要：The rotor profiles are the key factor of twin-screw compressor,but there is some inconvenience in modification and experiment of rotor profile. NURBS curves and computational fluid simulation analysis are applied to overcome these two problems. NURBS curves are introduced to construct a new rotor profile based on the rotor profile of unilateral asymmetric combined cycloid with pin gear arc. The equations of profile are given. The numerical simulation models of the new profile and the original profile are built to find out the distribution law of pressure and velocity in twin-screw compressors under the operating speed by the means of FLUENT software. Finally,according to the simulation results,the rationality of the designed rotor profile is verified,and new schemes for further optimization are explored. Then an experiment is made to describe the reliability and convenience of this design method.关键词：NURBS curve;Fluid simulation analysis;Twin screw compressor;Rotor profile
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发布时间：2022-09-22 - 摘要：The mechanical properties of hollow glass microsphere / epoxy syntactic foam can be reinforced by adding glass fiber. Two numerical simulation models have been established with two different hollow glass microsphere and glass fiber arrangements. The change rules between elastic constants and volume fraction,relative wall thickness and stress distribution rules are studied. It is found that the elastic modulus of composites increases with the increase of glass microsphere relative wall thickness,while the changing rules with volume fraction show different patterns in different relative wall thickness. Poisson’s ratio decreases with volume fraction increase,but it increases before then reduce with the relative wall thickness. The elastic modulus prediction formula along the fiber axial was proposed according to Voigt model and mix law. The prediction results are close to numerical simulation results when the relative wall thickness less than 0. 2.关键词：Glass fiber;Hollow glass microsphere;Syntactic foam;Elastic constants
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发布时间：2022-09-22 - 摘要：In order to improve the driving efficiency,and support technology,design a kind of stepping-type advanced supporting equipment which can be used for supporting on fully mechanized tunnelling. Analysis the mechanical characteristics of the roof of roadway and the working principle of the advanced supporting equipment,and establish the mechanics model of the advanced supporting equipment with roof. Establish the deflection equation of roof by the theory of structural mechanics and materials mechanics,and solve the deformation law of the roof with the help of computer aided software. Simulate the deformation of roof and supporting equipment using ANSYS software. Build advanced supporting prototype,and carry out simulation experiments about supporting characteristics combined with the simulation of roof. The simulation and experimental results show that,the roof has been supported effectively with the help of advanced supporting equipment,and the equipment has high value in engineering application.关键词：Fully mechanized tunnelling;Supporting in advance;Deflection equation;Supporting technology
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发布时间：2022-09-22 - 摘要：A 3D static finite element（ FE） model of a heavy haul track is developed to study the deformation of the track structure under an axle load of 40 tonnes,in which the rail-railpad-sleeper contact is simulated in detail. Focus of analysis is especially placed on the pressure distribution on the rail seat of concrete sleepers,which provides valuable data for future designs of heavy haul track structures of 40- tonne axle load. The FE model is first validated by comparing the calculated results with those of a traditional simplified algorithm. More results have shown that（ 1） the typical heavy haul track structure in China can meet the requirements of 40- tonne axle load,but the stress on the top of subgrade exceeds the bearing capacity considered in normal design;（ 2） with the increase of the lateral wheel-rail contact force,the width（ along the lateral） of the contact patch between the railpad and the sleeper decreases and the length keeps almost unchanged,thereby the maximum pressure increases and its location moves towards the field side in the lateral;（ 3） Under the typical wheel-rail contact forces,the pressure distribution on the rail seat changes significantly when the stiffness of the railpad increases from 80 MN / m to 200 MN / m,while un-affected as the stiffness further increases to 1300 MN / m;（ 4） Assuming a constant dynamic amplification factor,the pressure on the rail seat decreases as the rail fastening system fails,and correspondingly,the shape of contact patch between the rail pad and the sleeper becomes more irregular due to less constraints.关键词：40-tonne axle load;Heavy haul track;Railpad;Pressure on rail seat of sleepers;Finite element method
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发布时间：2022-09-22 - 摘要：In order to have a better research on the effect factors of the vertical axis wind turbine wind-energy utilization coefficient,based on the multi-blade element momentum theory a Double Disk Multi-tube Model was established,and through mathematical modeling method to focus on the influence of chord length,radius and number of blades. Because of the loading on the wind turbine during rotation was complex,the rotation plane was divided into four quadrants,and put forward the fourquadrant analysis method on the basis of the original theory,then established the simulation model based on the analysis of stress. Finally,in view of the NACA0018 airfoil,study respectively in different chord length,impeller radius and number of blades using the four-quadrant analysis method,the change of vertical axis wind turbine wind-energy utilization coefficient,which provides a reference for the selection of fan impeller parameters.关键词：Double disk multi-tube model;Four-quadrant analysis method;Wind-energy utilization coefficient;Impeller parameter
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发布时间：2022-09-22 - 摘要：Firstly the theory of Hertz was used to calculate the maximum stress of same angular contact ball bearings in the same condition and different internal and external channel curvature radius. And ANSYS APDL parametric language was used to establish three-dimensional finite element model of angular contact ball bearing and the model considers the radial clearance and axial clearance. ANSYS / LS-DYNA was used to load pre-tightening force,radial force,axial force and inner rotation on bearing.And comparative study on the theoretical analysis and finite element analysis was made to verify the validity of the finite element analysis. Finally,maximum stress of angular contact ball bearing was obtained in the different internal and external channel curvature,in order to provide scientific reference for the selection of channel curvature radius of angular contact ball bearings.关键词：Angular contact ball bearing;Channel Curvature Radius;Ansys/LS-DYNA
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发布时间：2022-09-22 - 摘要：Axial load carrying capacity is one of the most important mechanical property indexes of honeycomb structure. A new type of supercell honeycomb structure was put forward in which rhombus and circle were combined into the basic cell,and research was focused on its structural stability,overall strength and stiffness. By helps of finite element numerical simulation,the method of eigenvalue buckling analysis was used to realize the process of structural stability analysis of the supercell honeycomb,and the analysis result was also compared with those of rhombus,regular hexagon and regular octagon honeycomb structure.Meanwhile,a type of chassis deck of electrical motorcycle was taken as an example to testify the overall strength and stiffness of the new type of honeycomb sandwich structure’s core under axial load and analyze the influence on strength and stiffness of the core with different wall thickness of its cell. The results show that the new type of supercell honeycomb is an innovative configuration with good comprehensive mechanical properties such as better axial structural stability,high strength and overall stiffness of honeycomb sandwich structure’s core,and axial load-bearing capacity.关键词：Supercell honeycomb;Cell;Structural stability;Axial load carrying capacity
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发布时间：2022-09-22 -
CONTACT FINITE ELEMENT ANALYSIS OF JOINT BEARING LAMINATED MEMBRANE COUPLING UNDER COMPOSITE LOADING
摘要：In order to explore the stress characteristic of flexible components of the laminated membrane coupling,according to the contact finite element model of laminated group,the stress distributing graphs under the comprehensive load are obtained. Based on the finite element analysis software ANSYS,the geometric model of laminated group is provided,some contacts between the diaphragms are added and methods of applying different loads are proposed. Effects of number of diaphragm on laminated stress are analyzed,and distribution curve of maximum equivalent stress and contact stress on laminated group which from four layers to nine layers are obtained. With laminated group which have nine layers as an example,distribution curves of equivalent stress and contact stress due to different torques,different axial displacements and different angular displacements were obtained. Study shows that Mutative angular displacement is the key effect of laminated stress among various kinds of loading,and the breaking point first occurred around the washer on the lateral diaphragms under the action of composite loading. The compensation capacity,use efficiency of the laminated membrane coupling with joint bearing are greater than the laminated membrane coupling without joint bearing under composite loading.关键词：Joint laminated membrane coupling;Finite element;Comprehensive load;Equivalent stress;Contact stress- 3
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发布时间：2022-09-22 - 摘要：The need to design lightweight structures and the increased use of lightweight materials in industrial field,has led to wide use of adhesive bonding. In order to improve the mechanical strength and reliability of adhesive joints,the research results of mechanical property of adhesive joints at home and abroad was summarized,including the static analysis,fatigue analysis and dynamic analysis. The problems and development trend of mechanical property of adhesive joints have been pointed out.关键词：Adhesive;Static analysis;Fatigue analysis;Dynamic Analysis
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发布时间：2022-09-22 - 摘要：Exhaust manifold is a main heated component of engine,which has poor working conditions. High levels of thermal load can lead to deformation even cracking,which affect its normal working and reliability and durability. Aiming at the high thermal load of a high pressure common rail diesel engine,different fluid-solid coupling models was built and the temperature distribution and thermal stress of the engine exhaust manifold was stimulated and the influence of different structural factors on the exhaust manifold thermal load was calculated and analyzed. Results show that: the maximum temperature of the exhaust manifold changed from 805. 2 ℃ to 820. 8 ℃ as the outlet length increased,the maximum temperature of the exhaust manifold changed from 805. 2 ℃ to 819. 4 ℃ as the outlet diameter increasing,and the maximum temperature of the exhaust manifold dropped to 784. 0 ℃ as the outlet transferred to the body symmetry position. Structure factors such as exhaust outlet position,outlet length and outlet diameter had a great influence on the exhaust manifold thermal load. The maximum thermal stress value was 326. 21 MPa of the case of 21 mm outlet length and 5 mm outlet diameter outlet with the non-symmetry outlet position; the minimum thermal stress value was 174. 1 MPa of the case of 19 mm outlet length and 5mm outlet diameter with the non-symmetry outlet position.关键词：Exhaust manifold;Thermal load;Computational Fluid Dynamics（CFD）;Finite Element Analysis（FEA）;Coupling
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发布时间：2022-09-22 - 摘要：Loading spectrum acquired from proving ground contains a large percentage of low-amplitude loads. For accelerated durability test spectrum development,many small load omission criterions（ SLOC） have been induced. However,only the damage effect of low-amplitude loads was considered. The strengthening effect was ignored in the traditional SLOCs. A new SLOC was induced by considering the strengthening effect. This criterion was applied to develop target spectrum of a certain load section from proving ground,and an accelerated spectrum was created. To verify the validness of this methodology,analyses of original spectrum and the accelerated spectrum were conducted from multi-aspects,including amplitude domain（ level crossing counting and rain-flow counting）,damage domain（ damage reservation and rain-flow cycle damage distribution）,and frequency domain（ shock response spectrum and fatigue damage spectrum）. The results show that the accelerated spectrum has reserved spectrum damage,guaranteed damage distribution characteristics and frequency characteristics. Finally,vehicle bench iteration test was conducted,and results show that original spectrum can be replaced by the accelerated spectrum as the durability test spectrum. The validness of this methodology has been demonstrated.关键词：Low-amplitude load;Small load omission criterion（SLOL）;Development of spectrum;Accelerated durability test
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发布时间：2022-09-22 - 摘要：The tensile stress-strain response for 6016 aluminum alloy（ AA6016） sheet under different strain rates was presented in this paper. The data were fit to the Johnson-Cook constitutive model and fractured strain model. The energy absorbing performance of AA 6016 thin-walled square tubes under axial impact were analyzed. The results show that flow stress of AA6016 is insensitive to strain rate,while fractured strain is sensitive to strain rate. Thin-walled tubes show good energy absorbing performance with progressive buckling deformation under axial crushing. However,the energy absorbing performance decreases due to the mix buckling mode with the increasing thickness,length and impacting velocity of aluminum alloy thinwalled tubes.关键词：Aluminum alloy;Thin-walled tubes;Deformation;Fracture;Axial impact
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发布时间：2022-09-22 - 摘要：It is the stress intensity factor of crack tip on crankshaft of internal combustion engine that is the basis for calculating crack growth and residual life. Firstly,this paper using ADAMS software on the connecting rod system of crankshaft,analyzed the dynamics of rigid flexible coupling,draw that the fourth crank make maximum load. So in other same boundary conditions,the most prone elliptical crack is the direction of 45 DEG angle with the shaft shoulder,in the transition fillet of the fourth crank pin and Shaft Shoulder The load of the dynamic analysis calculation is regarded as the main force to calculate the intensity factor near the crack tip. Draw the trend of intensity factor with the crack depth changes under the different long and short axis ratio a / c. Under the condition of in considering the crack depth and the crack’s long and short axis ratio’s influence then fitting the expressions of shape factor of EQ4 H type internal combustion engine crankshaft. Laid the foundation for the followup work of fracture mechanics for this type internal combustion engine.关键词：Crankshaft;Stress intensity factor;Crack propagation;Long and short axis ratio;Crack depth;Fitting
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发布时间：2022-09-22 - 摘要：In order to carry on life determination on certain engine fan blade,high and low cycle fatigue tests were conducted on several specimens. The fatigue characteristic curve（ S-N curve,P-S-N curve） was obtained by statistical analysis.The results show that the S-N curve of this blade meet the law of quadratic function when the high cycle stress is greater than61. 51 MPa. In contrast,the high cycle fatigue is over the fatigue limit of general metal. The service life is associated with high cycle stress linearly. The disparity of service life is lower under high stress,while it is higher under low stress. In addition,the median life is about 2. 5 5 times of the safety lfe（ the survival rate is 99. 99%）.关键词：High-low cycle complex fatigue;Fan blade;Finite element analysis;Fatigue characteristic curve;Fatigue life
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发布时间：2022-09-22 - 摘要：Body improvement of lightweight mini-truck made vehicle mass reduction of 10. 9kg. After constraints and forces is carried out to calculate the bending stiffness and torsional stiffness around the vehicle in the pre-processing software of the finite element to model,in the contrast,it is found that the bending stiffness fell 1. 28 percent,and 2. 49 percent decline after the torsional stiffness,so they are down slightly. Tests of mini-truck is done on the real enhanced road,it is good performance.关键词：Vehicle stiffness;Light weight;Mini-truck
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发布时间：2022-09-22 - 摘要：Bucket force is simplified as concentrated force or uniform force in traditional bucket strength analysis,which will result in inaccurate bucket strength analysis result. Taking Sandvik 1400 e scraper as an example in this paper,carrying out pretreatment on the bucket based on Hyper Mesh,simulating scraper working process by EDEM,it is obtained that bucket is characterized by complication and variable load during scraper operation. By way of coupling discrete element and finite element,bucket was loaded precisely,then bucket strength analysis and wear calculation were completed,which will provide theoretical basis for bucket structure optimization.关键词：Scraper bucket;Discrete element;Finite element;Coupling;Strength analysis
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发布时间：2022-09-22 - 摘要：The furrow plough’s strength was designed by theoretical analyses and experimental strain analyses to make sure the design reasonable and accurate. As fully-loaded tractors run at a low speed,by theoretically analyzing the stretch-bending combined-deformation strength,the calculated results were used as design basis. By experimental analyses and the strain rosette theory,under the same conditions,strain values are measured by resistance strain gauges as the calculation basis. The experimental analyses further verify the security of theoretical calculations. When designing agricultural machinery,combining the theory and experiments ensures the components’ reliability. So strain analyses are good and simple methods to design the complex structures.关键词：Agricultural machinery;Work security;Theory of strength;Strain analysis;Full load with low velocity
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发布时间：2022-09-22 - 摘要：In this paper,on the basis of the finite element method,the dynamic simulation analysis and fatigue analysis,co-simulation of finite element and multibody dynamics was used to predict the crankshaft fatigue life. MSC. Nastran was used to make the modal analysis for getting the modal neutral file（ *. mnf）. The rigid crankshaft was replaced by the flexible crankshaft,then this paper built a coupled multi-body dynamics model of engine by using ADAMS. Load history for the crankshaft is calculated in ADAMS,then import the gotten. dac files into MSC. Fatigue. Analysis of the crankshaft fatigue life is completed.The results may be valuable for optimal design of crankshaft.关键词：Modal analysis;Crankshaft flexibility;Dynamics;Load history;Crankshaft fatigue life;Cosimulation
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发布时间：2022-09-22 - 摘要：Currently,the production process of firecrackers is very complex. Each station is fragmented and is far away.Firecrackers production needs long-distance transport for many times by human. Consequently,the production efficiency is low.In this paper,a new fast reusable hexagonal dispatching clamp is designed and the reliable clamping and shaping effect of new fast hexagonal dispatching clamp to hexagonal firecrackers cake is simulated by using explicit dynamic procedure of ANSYS / LSDYNA,the ideal of perfectly clamping and shaping is demonstrated by using the new fast dispatching hexagonal clamp to hexagonal firecrackers cake. It provides a feasible method and has important reference for multi station automatic integrated production of fireworks.关键词：Firecracker;Fast dispatching hexagonal clamp;Ansys/LS-DYNA;Simulation
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发布时间：2022-09-22 - 摘要：Diagnosis and resolution faults of gas bearing turbo- expander influences the operation of refrigeration system.Through the analysis of the structure of gas bearing turbo- expander is of great importance for fault diagnosis. Crashes,caused by the rotor imbalance,was eliminated by static balance and dynamic balance test,when gas bearing turbo- expander was started and run,it should be regulated not to overspeed to ensure that rotor were not overloaded. The reason of gas bearing stability was analyzed,caused by the radial load and frequent start-stop and flash power outage. The relationship between gas supply pressure,radial clearance and the rotor balance was analyzed. Clearance,between the machine shell and wheel,could be adjusted to avoid the increase of the internal leakage. Measures was adopt to reduce external leaks,such as adjusting the sealing gap at the back of the wheel and providing plenty of sealing gas. The causes of liquid impact fault was analyzed,and processing method was put forward. Failures caused by gas pipeline jam and unclean bearing gas were analyzed. Methods are proposed to ensure safe and stable operation of the turbo- expander gas bearing,such as rigorous test of dynamic and static balance,the correct assembly,standardized operation,and regular maintenance.关键词：Gas bearing turbo-expander;Fault;Crashes;Rotor overload;Gas bearing stability;Leakage;Liquid impact
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发布时间：2022-09-22 - 摘要：In this paper,the use of local synthesis method,study the tooth contact analysis（ TCA） of the CRH5 traction gear by programming with MATLAB,respectively,calculate contact tracing line on the tooth surface and the graph of the transmission error of the middle point,huge end and small end respectively,and the graph is analyzed and explained,not only improves the direct use of TCA method to solve tooth contact,such as programming complex,time-consuming,and laid a good foundation for the rational design of cutting parameters of the spiral bevel gears.关键词：Spiral Bevel Gear;Contact analysis;Transmission Error
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- 310
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发布时间：2022-09-22 - 摘要：Based on i SIGHT multidisciplinary optimization platform integrated finite element analysis software ABAQUS,the sub-model technology,global optimization strategy,hybrid iterative optimization algorithm and parametric modeling method of spline curve were used in optimization design of sealed-module structures,which greatly reduced the single-solving time and improved the efficiency of entire optimization process. The weight and stress of sealed-module structures are reduced significantly after optimized and the optimization result are verified by hydrostatic test. This method solves a problem of high stress of sealedmodule and provides a referenced technical route for optimization design of sealed-module in future.关键词：Sealed-module;Multidisciplinary optimization platform;Optimization design
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- 225
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发布时间：2022-09-22 - 摘要：A truckborne radar system is widely applied in communication,radar navigation and electronic countermeasures,etc,and it can work in an extremely harsh field environments. The antenna-feeder system of a truckborne radar,due to its working characteristics,the wind load is its main load,analysising its wind loads has an great significance to guarantee structural strength and stiffness. This article using finite element method for the radar antenna-feeder system of mechanical characteristics of static and transient under wind loads,analysis its structure’s characteristics of displacement,stress and strain under static and dynamic loads change over time by using transient dynamic,and giving the analysis of the moire fringe,providing basis of optimal design of antenna-feeder system.关键词：Antenna-feeder system;Wind loads;Finite element analysis;Stress;Strain
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- 81
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发布时间：2022-09-22 - 摘要：Double arc gears are widely used in high load speed reducers,and the inherent mode has an important influence on the performance of the reducer. Computational modal analysis is an efficient method for modal analysis of components using finite element software. In this paper,the modal analysis of the double arc gear was carried out using ABAQUS / CAE software,and discussed the gear in the gear spiral angle on the impact of modal. It will provide basis for dynamic performance optimization,vibration fault analysis and prediction.关键词：Double arc gear;Finite element;Modal analysis
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- 164
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发布时间：2022-09-22
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