The machining process simulation of single grain with negative rake angle was performed by using the FEM software Deform-3D,and the rotating axial ultrasonic vibration surface grinding experiment device was designed and manufactured,which was used to carry out the experiment.The surface residual stress of 45 steel in different grinding conditions were measured respectively.It was found that the relative error was between 2.47% and 16.93%,which verified the correctness of the the finite element model of grinding surface residual stress.The simulation results show that:residual compressive stress is produced on the workpiece surface by generally and ultrasonic grinding,and the residual compressive stress in the axial direction is significantly greater than that in the grinding direction.The surface residual compressive stress increases with the increase of the amplitude,the grinding depth,the negative rake angle of the grain and the frequency of the ultrasonic vibration,and decreases with the increases of the speed of the grinding wheel.

It is of great significance to set bottleneck buffer to improve the stability of production system and the efficiency of output.According to the complex operating conditions of multi workpiece,multi working procedure and multi machine in the production of air suspensions,the basic model of bottleneck buffer which make the bottleneck procedure wait for the shortest time and make the cost lose least is established based on the fault degree and maintenance degree of machine,the Working in Process (WIP) inventory cost,the loss of bottleneck shutdown and the abnormal production fluctuation.In addition,the basic model of bottleneck buffer is amended according to the interval of process caused by the strategy of batch processing and withholding workpieces.At last,this modeling method is applied to validate the production scheduling of the key components in mechanical structure of the air suspensions and forecast the best bottleneck buffer accurately.

To achieve the automation of loading automobile tires and improve the loading efficiency,a set of tire loading system was designed,and a stacking algorithm was proposed.The algorithm can give the best stacking layout of tires and achieve the intelligent stacking of tires on the truck according to the parameters of trucks and tires.The stacking layout of tires was analyzed and optimized using the constrained optimization method.In order to verify the feasibility of the algorithm by example,the stacking algorithm was designed based on the MATLAB GUI.

A design scheme of holding device for die-changing manipulator was presented with the feature such as three degrees-of-freedom,good rigidity,high temperature resistant,safe and reliable.The description on the composition and function of holding device is showed in details,and design principle for holding mechanism,telescopic mechanism,lifting mechanism were particularly described.Finally,the kinematics simulation for the design scheme was carried out through DELMIA.Simulation results show that the holding device can perform clamping,lifting,telescopic for die in X,Y,Z three coordinate direction,and can meet using requirement.

Based on the FLUENT fluid simulation software,the design and simulation analysis of the exterior shape of the pneumatic control gliding underwater robot is carried out,and the design of the underwater robot in the flow field is more efficient.Firstly,the pneumatic control gliding underwater robot is introduced,and then th7e design and simulation analysis of the main carrier shape and the gliding airfoil is carried out on the basis of its internal structure,from which to select a relatively optimal scheme.FLUENT software simulation analysis can provide important theoretical basis for the optimization of underwater robot shape,better underwater experiments,and shortening the design cycle.

In Additive Manufacturing (AM) filed,the traditional STL file format contains only geometric information,without any materials information.Therefore,it cannot be applied to fabricate multiple material parts.Aiming to solve this problem,presents a new multiple material file format for additive manufacturing,MMS format.In this format,material index is introduced to identify material type of each region (such as basic material and functionally graded material),meanwhile material distribution function is used to describe material distribution in spatial regions.Moreover,the surface color information is added to multiple material model.Some cases verify that the proposed file format can be used to represent the multi-material model,and slice layer contains material information,which can be applied for additive manufacturing.

With the development of digital technology in the stomatology application and digital fabrication of dentures will be the trend in the future.During the process of digital fabrication of dentures,3D printed dental casts will replace traditional plaster casts.Preparing standard cylinder and rectangular specimens by 3D printing and pour plaster impression and measuring the mechanical properties and surface roughness of specimens are indirect comparison with 3D printed dental casts and traditional plaster casts.Besides the dimensional accuracy of them are analyzed in comparison.Compared with traditional plaster casts,3D printed dental casts are less in hardness,but better in compressive strength,bending strength and surface roughness.The dimensional accuracy of 3D printed dental casts is similar to traditional plaster casts,but the consistency of 3D printed dental casts is better.Comparative analysis between 3D printed dental casts and traditional plaster casts,the study shows that 3D printed dental casts which are more superior to traditional plaster casts,can fully replace traditional plaster casts for digital fabrication of dentures.

By comparing the braking torque of permanent magnet brushless DC motor in full and half bridge modulations,the advantages of motor braking energy recovery in full-bridge modulation are obvious.Then the Anti-lock Braking System(ABS) with pure electric braking based on slip-rate in electric vehicle is designed with PID strategy by analyzing the control principle of ABS based on electric braking in full-bridge modulation,so that the problem of wheel lock during braking is solved.A single wheel vehicle dynamics model is developed in Matlab/Simulink based on the braking mathematical model of brushless direct current motor in full-bridge modulation,the model is simulated on the high,middle and low-adhesion road.The results show that the created system has fast response,precise control and good stability,the slip rate is kept within ideal range,the ABS runned effectively.

Based on the modal displacement response the time history of modal stress of car body is determined by the method of modal stress recovery theory.Then the fatigue life of carbody is evaluated by the Miner accumulated fatigue damage theory.According to the analysis of influence of mode of vehicle on the fatigue life,the first ten modes of carbody with low frequency has the great influence on the fatigue life of car body,but the modes with high frequency has little effect on the fatigue life.Meanwhile by the analysis of influence of single mode on the fatigue life of the various parts of carbody,the first order vertical bending mode of carbody has the bigger impact on the fatigue life of carbody.

For the active steering and yaw moment integrated control for four-wheel independent drive electric vehicle,the integrated control method is studied based on the optimum control theory .The vehicle integrated control structure is determined.The integrated controller is designed based on the optimum control theory.The drive forces distribution are designed by using the rule allocation method taking the advantage of that the four wheel drive torque are controlled independently.The integrated controller outputs the additional steering wheel angle and the additional yaw moment value based on the difference between the actual yaw rate and the ideal yaw rate and the difference between the actual side slip angle and ideal side slip angle,which is necessary to ensure the vehicle driving stability.The additional steering wheel angle is attached directly to the steering wheel.The additional yaw moment is distributed by driving forces distributor.The typical work condition is chosen and the control method is verified based on the driving simulator hardware in the loop test bench.The results show that the integrated control can make the vehicle follow the expected value and improve the vehicle driving stability effectively.

Production logistics would affect output rate directly,for the main question of not to delivery in time in a company of main produce car,to finding the main key link is very important.It was found by observation and analysis that was the painting process in affecting the yield of automobile.Painting production logistics included five stations that pre-treatment,coating,inspection,drying and scratch,according to the current job situation of each station,the application of Witness software in modeling and simulation,the running result revealed that the coating station was the bottleneck because of the station was only one line and sometimes needed to spray a variety of colors,two spray coating lines were added to solve the problem which waiting too long and moving back and forth,a new model used Witness was established and the result showed the production line running blocking has been obviously improved,the average time of painting processes reduced from 100 to 88.5 minutes.The improvement scheme applied in the enterprise,the car’s the monthly output increased from 1 000 to 1 250 units,for the enterprise created a good economic benefit.

BASE board is a crucial part which supports the body of the cars and the rod bed in the production line of cars welding.384 kinds of MSC.PATRAN finite element solid and surface models are built,respectively,by different selections on U-steel type,quantity and space of stiffeners with the parameterization-geometrical modeling technology.And by the analysis of MSC.NASTRAN,it gives the optimal design of stiffeners allocation with the premise of deflection smaller than 0.2mm,which can provide the valuable reference frame for BASE board design.

Based on a real vehicle parameters to establish a bus chassis dynamic model with ADAMS,according to the national standard to simulation,and verified the validity of the model;air suspension guide mechanism parameters were selected as factors in this orthogonal experiment.The main factor which effects the turning performances is found.Use of signal-to-noise ratio,has carried on the calculation for the data from simulation,obtained parameter combination which signal-to-noise ratio is maximum.At the same time,it is also proved that the structure parameters of the air suspension guide mechanism have important influence on the vehicle steering characteristics.

In order to optimize the NVH performance for roof,firstly,based on the plate-beam structural dynamics theory,the dynamic model of roof structure was established,and its calculation formula for natural frequencies is obtained.Secondly,study respectively the impact on dynamic characteristics due to changing of aspect ratio of roof reinforced beam and plate-beam thickness ratio.And then uses the structural topology optimization and the modal strain energy analysis technology,obtained the sensitive structures of a car roof for bend vibration modal.Finally,synthesize the roof dynamic mechanics theory and the car body modal characteristics,puts forward reasonable optimization schemes for NVH performance,which can provide theoretical basis and scheme for the roof structure optimization.

Using the Pro/E and Kisssoft software modeling ZC1 worm,and importing them into ANSYS modal analysis.To study the effect of multiple factors ZC1 worm natural frequency,especially divided into two experimental groups,the first group of states with different constraints into a free state,bound state,the state assembly,the second group with different structures and materials,respectively research worm tooth structure,the worm first few material impact on the shaft. Finally,modal test to verify the correctness of the assembly model,provide the basis for the description and optimization of the overall performance of the vibration characteristics of the system architecture.

Take T80 series of car roof cover as the research object,analyzes the structure characteristic and performance requirement of automobile top cover.Using AutoForm software on the roof cover drawing forming numerical simulation analysis,predic sheet metal forming process in thinning,cracking,wrinkling and other defects,choose different blank-holder force value to optimize sheet metal forming process parameters.Through the simulation results and the actual production,the results were compared to verify the correctness of the simulation analysis.Application of numerical simulation technology has an important significance to shorten the development cycle of mold,reduce costs,improve the quality of stamping products.

To optimize performance and internal flow field structure of centrifugal,numerical simulation is applied on impeller flow field structure in throwing snow centrifugal fan named P4-35-01No.03.First,three-dimensional entity model is set up in Creo software,set up the import entity formation fluid field in ANSYS software,and then based on Fluent software analyzes fluid.Through changing primary structural parameters,observe impeller flow field character of centrifugal fan with different structural parameters.Increasing impeller inlet pitch,the snow flow in outlet will decrease and velocity of snow parts will sharply increase.Decreasing blade initiative pitch,snow flow in outlet will remarkably reduce,that lead to hinder velocity of snow parts in outlet raise.Decreasing blade outlet angle will be beneficial to optimize phenomenon——snow parts unequally distribute in impeller.When blade outlet angle is 20°,velocity distribution of all flow pass in impeller are consistently distributed in circle direction.Research results discover some defects in original designs,provide the reference basis for the design and production of the centrifugal fan impeller in the future.

In order to analysis the torsional vibration changing law of the 4100QBZL diesel engine crankshaft,a finite element model of crankshaft is built in ANSYS.A model analysis is carried out.On the basis of modal analysis,the crankshaft of the flexible body neutral file is built.The coupled multi-body dynamics model of crankshaft system is established,the motions is cylinder pressure as experiment data under many conditions.After the simulation,the main journal,connecting rod journal load results is got.Then torsional vibration simulation is operated,crankshaft torsional vibration amplitude with the load and speed is obtained.Results show that with the increase of engine speed and load,the torsional vibration of crankshaft are tend to be larger,and speed greater influence on torsional amplitude values,the shafting vibration amplitude under various conditions satisfy engineering demand.The simulated results can be used to improve the NVH of diesel engine in optimum design.

By means of orthogonal experiment,the effect of cutting factors(cutting speed,feed rate,depth of cut) on cutting forces is studied when dry cutting 304 austenitic stainless steel (0Cr18Ni9) with Al₂O₃/(W,Ti) C/CaF₂ gradient self-lubricating ceramic tool.Orthogonal table is used to perform the analysis of variance and F-test to confirm the primary and second order and significant influence of cutting parameters on cutting forces;empirical formula of main cutting force is established by exponential regression analysis.It can be indicated that main cutting force may be smaller than radial force in given range of cutting parameters.The result shows from F-test that feed rate and depth of cut have significant effect on cutting force.Main cutting force and radial force increase with the increasing feed rate and depth of cut.

For linear and circular two kinds of weld defects,proposed a method of weld defect type recognition algorithms based on Support Vector Machine (SVM).First of all,some image pre-processing algorithms such as fuzzy C means clustering,region filling algorithm,average filtering,edge detection,Otsu thresholding and inverse thresholding,to get the approximate location of weld defects.The information of the particular region will be extracted using segmentation based fractal texture analysis,SVM is used to classify the segmented defect as line or circular defects based on the extracted features lastly.The results showed that,the average accuracy rate is 97.5% for correcting identification of the type of weld defects,by 150 weld X-ray image is trained and 80 X-ray image weld test,which can meet industrial requirements.

An optimization design for internal pressure water bulging process of new type of stainless steel straigh-through pipe joints is introduced,the second water replenishment and the turbocharging technology is adopted to realize synchronous pressure supplement and precise positioning for mould,and overcome the difficulties in complicated internal high pressure water bulging process and hard to position precisely,which has resulted in bottleneck problems such as inconsistant wall adherence,poor forming quality and energy consumption and so on, energy-saving analysis and verification has been done as well.At the same time,sample machine has been made and after operation,it is found that the cost has been reduced significantly,and the pipe forming quality is high,which has proven that this plan is feasible,and has provided preferences for improvement of all kinds of water bulge forming process.

The sample data of the rotating center of the alignment platform collected in the process of motion calibration for the bonding equipment has so many interferences,which cause a lot of problems like complexity,low accuracy and robustness in derivation process.In order to solve the problem, figures out a simple solution based on Random Sample Consensus(RANSAC)algorithm.By carrying out iteration screening several times with the solution based on the density distribution model of the sample data,we can derive the results on the basis of the optimum solution.The experimental results show that by using iterative calculation within 10 groups of random sample datum,it costs 697.6 seconds on average,and the calibration accuracy of this method is within 7.2 pixels. Besides,the results of the 7 datasets all meet the precision requirement of the 10 pixels.The results reach the same performance level of the Japan and South Korea’s equipment and absolutely conform to the requirements of the equipment operation.

In order to investigate the magnetic field characteristics of a disk type shear yield stress measurement instrument,the magnetic circuit composition of the measurement instrument was introduced based on Ohm’s law of magnetic circuit and Ampere circuital theorem,and a simulation of the magnetic circuit is conducted in ANSYS firstly;moreover,the experimental analysis on the uniformity of magnetic field,magnetic flux density and measurement precision of the instrument is performed.The simulation result shows that the magnetic flux density in the working gap distributes uniformly and increases with the increase of the exciting current,the magnetic flux density in the working gap can reach 0.9T under the current 3.0A;the experimental results show that the shear yield strength measurement instrument can meet the needs of the measurement of magnetorheological fluid characteristic.

To improve the accuracy of speed hydraulic system and overcome the nonlinear time-varying problem,the fuzzy control strategy for the motor speed was proposed.The power source was the servo motor,which drove the dosing pump,and then the fuzzy controller of the system was designed.Based on Labview test and control platform,the model of the fuzzy controller for the motor speed is evaluated.In order to compare the control effects of traditional PID and fuzzy control system,the experiment for dynamic response and load disturbance rejection capability were carried on respectively in the two control strategies.The results show that the robustness of the fuzzy control is better than traditional PID,but the dynamic response characteristics are similar.

In view of the nonlinear,strong coupling and time variation characteristics of industrial actual flying shear control system,the fuzzy adaptive PID control algorithm is designed to replace the common PID control,and the closed-loop servo control system is established. After the simulation of the control theory and control system,the motion control function library of Googol CPAC and the fuzzy control toolbox of MATLAB are combined to design VC++ motion control program. The flying shear control system has good stability and high control precision,which can meet the actual production requirements.

Through the collection of road load spectrum from test ground and the indoor road simulation test,the precise simulated response spectrum was obtained,and the vibration situation of the car was established.By using the UG software and multi-body dynamics simulation software ADAMS,the virtual rigid-flexible coupled road simulation test platform is built with reference to the actual AMT actuator multi-axes road simulation test bench.The outcomes are verified by actual collected spectrum and road simulation test results.Simulation analysis is conducted with the achieved road simulation excitation as input,thus the new virtual vibration test method for AMT actuator based on road simulation excitation spectrum is established,and effective approach and method for AMT actuator vibration fatigue reliability assessment are provided.

The reasonable classification of iron and steel scrap is the basic link of the delicacy management in the reverse supply chain for the iron and steel industry.For making full use of scrap iron and steel,the cyclic utilization is analyzed and a classification model based on the source,geometry appearance and chemical composition is proposed for the scrap iron and steel in the reverse supply chain.With the low versatility of the existing classification and the huge data of the chemical component,the dimension matrix composition data is reduced by the using of the principal component analysis at first.And then the initial cluster number and initial clustering result is obtained by hierarchical clustering method.Finally,a suitable classification has been constructed.In the end,the initial clustering result is optimized by applying ant colony algorithm.In a case of classification of 413 types of scrap iron and steel,9 kinds of chemical elements are regarded as an index of calculation.Finally,these scrap iron and steel can be classified in 5 species of scrap iron and 7 species of scrap steel.The chemical composition of each species is significantly different.This conclusion can solve the problems of warehouse layout and process decision and production scheduling in the iron and steel industry.

From the angle of vibration signal complex for rotation machine,the construction of characteristic entropy is studied and a set of multi-scale fuzzy entropy is put forward to identify the vibration signal with different faulty.Accounting for theory defect of traditional faulty identification which depends on prior knowledge,the identification method based on variable predetermination model is instructed into faulty diagnose for rotation machine.The new method is applied in a living example,which show the method is effective.

For the missing fault of brake shoe in trouble of moving freight car detection system,a staged matching algorithm based on radian step is proposed.A regional image which contains normal brake shoe is intercepted as the template,then the contour moment invariants are calculated after template is preprocessed.In the image to be inspected,the excircle of wheel was extracted.The center point of the circle was set as another origin,where a new coordinates was established.Circular arc in the forth quadrant is chosen,from which the points regarded as determinative ergodic path are calculated by selected radian step.During the first stage of ergodic process,corresponding matching similarity of each ergodic points measured by normalized correlation algorithm is calculated between template and template window in the image to be inspected.Then the second stage of ergodic process’ region was calculated according to the maximum similarity and its coordinate.Finally the region of brake shoe is located.The experiment results has shown that the algorithm can avoid the interference of complex background effectively,make inspection on brake shoe more accurate and much quicker,and can satisfy the instantaneity of the inspection on brake shoe.

Lightweighting of automotive structure is an effective method for emissions reduction and energy conservation with significance for improving energy and environment problems.First,summarizes the main methods of automotive structure lightweight that includes size optimization,shape optimization,topological optimization and multidisciplinary multiobjective optimization;then introduces some commonly used optimization algorithm of automotive structure lightweight:genetic algorithm,neural network method,micro particle swarm algorithm and so on;henanalyzies the main technical difficulties of structural lightweight design;finally states the development trend of vehicle structural lightweight.