A new type of double-frequency conversion vibration structure is proposed for the loading of high-low frequency vibration in the study of metal material strength.Firstly,the kinetic model of the structure is established,and a detailed kinematics equation is given.Secondly,the three-dimensional model of double-frequency conversion vibration structure is established.The key gearbox components are analyzed and validated by ANSYS software.Its control system is also constructed.Finally,the vibration characteristics of double-frequency conversion vibration structure are studied.The experimental results show that both of the high-frequency and low-frequency vibration can be controlled and it can also provide single-frequency amplitude and double-frequency superposition amplitude.The experimental data of vibration characteristics is in good agreement with the results of the dynamic model,which proves the correctness of the dynamical model.

A research method of changing the size of working mechanism on the digging force of hydraulic excavator was presented.Considering the arm digging and the bucket digging in the digging operations.The working mechanism size of excavator with similar weight were selected,and the digging force analysis was carried under factors of boom,arm and bucket.According to the simulation software,the digging forces of each oil cylinder were obtained and the corresponding digging force curves were drew.Taking a excavator with similar tonnage as an example,the influence of each size of the working mechanism on the digging force play was verified.The research results show that a digging force calculation model is built to compare each group digging force tendency.In the arm digging,with the change of the arm size,the change rate of maximum digging force of arm is 10 %.In the bucket digging,with the change of the bucket size,the change rate of maximum digging force of bucket is 12 %.The method for the design of the working mechanism has important significance.

The dynamic and static feature researches on new and old yaw damper and various installation length of yaw damper are accomplished.It could be concluded that there is no obvious change on static feature,but dynamic feature declines significantly with respect to static after it worked 1.2 million kilometers.Dynamic damping reduces about 10 % and dynamic stiffness descends 15 % probably.Dynamic damping and stiffness reduction rate decreases gradually as amplitude augments and dynamic damping manifests apparently than stiffness.Static feature also shows unconspicuous variation as dynamic damping and stiffness declines with the improving of installation length.Dynamic damping reduces about 2 %~8 % and dynamic stiffness descends 5 %~7 % probably while installation length aggrandizes 40mm.Meanwhile,Maxwell model is not reliable to analyze the its effect on vehicle dynamic performance,it embodies the limit of Maxwell model.

Based on the ANSYS Workbench platform,influence of the super-lift system and geometric parameters influence on the critical lifting capacity of the telescopic boom is studied.It is proved that super-lift system can be installed at a reasonable position and angle of the super-lift mast is expanded properly will increase critical lifting capacity of the telescopic boom.The super-lift also may become a load to decrease the critical lifting capacity.The critical lifting capacity increases first and then decreases with the increase of angle φ of the super-lift mast.The critical lifting capacity gradually decreases first and then increases rapidly with the increase of length H of the super-lift mast.When the length of super-lift mast reaches a certain length,the critical lifting capacity enhancing effect is not obvious with the continuing increase.The critical lifting capacity increases with the increase of distance L between the hinge point of the super-lift mast and the telescopic boom to the basic jib root,which means that it is most favorable that the super-lift mast is mounted near the base end of the basic jib.

Engineering change propagation brings risks to the operation of the project,in order to control risks of complex product engineering change,basing on the complex product design network,the structure matrix of complex product design network is constructed and the mechanism of engineering change propagation is analyzed.The nodes in the complex product design network are screened in order to obtain the Hub nodes.From the two perspectives of the direct and indirect effects of Hub nodes in the design network,the risk analysis model of complex product engineering change is constructed.Finally,the rationality of the proposed method is verified by the model HFC6564-84K marine generator.

In order to explore the effect of machine failures on tardiness delivery and product quality declining in MTO( Make To Order) environment,an integrated model to jointly determine equipment maintenance planning and Flexible Job-shop Scheduling Problem(FJSP) was established to minimize tardiness penalty cost and maximum product quality rate.Proposed a new hierarchical biogeography-based algorithm to solve the problem,which divided solution spaces into up and low level.In this algorithm,hierarchical iteration evolutions and multi-local search polices were designed,which accelerated the convergence speed and improved the quality of optimization.Compared with the Genetic Algorithm (GA) and Biogeography-Based Optimization (BBO ) algorithm,experimental results show that the approach is effective.

Heat treatment is the bottleneck of the mould manufacturing process,and will have a significant impact for the entire mould of the delivery time and manufacturing costs.The production scheduling of the heat treatment plant has the characteristics of batch dispatching.In the two-stage flexible flowshop,subcontracting is considered.The production plan of heat treatment workshop is divided into three levels:periodic rolling plan,quenching stage machining plan and tempering stage machining plan.With the scheduling objective of minimizing the manufacturing cost,algorithms are proposed for these three stages,respectively.An extensive simulation study is conducted to verify the effectiveness of the proposed strategies.The experimental results show that the manufacturing cost of the setting minimum waiting jobs rule strategy is obviously higher than the other three strategies.Without considering subcontracting,the scheduling strategy is slightly better than the setting maximum waiting time rule strategy,and the performance of scheduling strategies with considering subcontracting is the best among the four strategies.

The municipal solid waste compacting garbage station is a new type of garbage transfer station of city life.In order to improve the comprehensive mechanical properties and achieve the purpose of lightweight for the box,Three different designs for the arrangement of stiffening rib are provided,which take the arrangement of stiffening rib and the wall thickness as design variables.In the meanwhile the method of finite element analysis based on ABAQUS is adopted to optimize the design.Then the lightweight design can be realized by reducing the weight.The results show that the weight of box reduce by 715.8 kg.

In order to improve the processing quality of hydraulic turbine blade,static and dynamic finite element analysis on saddle of the hydraulic turbine blade processing machine tool was carried out. Through conducting three-dimensional modeling and mesh generation on the saddle of a hydraulic turbine blade processing machine tool,a simulation model of saddle was built in according to the load and constraint in the machine tool saddle’s practical operating condition.On the basis of the saddle’s simulation model,the static stiffness and modal properties was studied.The accuracy of the modal analysis results was verified by experiment.The static and dynamic finite element analysis on hydraulic turbine blade processing machine tool’s saddles has provided helpful references for the structural optimization design of saddles.

In bone surgery,bone drilling occupied an important position,the drilling temperature is an important factor of affecting the bone cell necrosis.In order to study the effect of different factors on the drilling process temperature.Simulation based on the ABAQUS finite element software.The python language was used for pre-processing module of ABAQUS for optimization.Modify the python script of drilling model,create a parametric model of bone drilling,which effectively simplify the tedious process of model building and establish a friendly interface,provide users with a convenient platform for analysis and design.Verified the feasibility of the function by experiments and gave a way for further research on different drilling rates on the drilling temperature in bone drilling.

At present,the main data interface file formats is:STL,IGES,STEP,etc.STL document has become standard format of a rapid prototyping manufacturing.The Pro/E 5.0 was taken to model the scaled track as an example and convert the part file to STL file.Setting different values of the height (A),angle control (B),step size (C),conducting orthogonal test to analyze the effects of them on the molding efficiency and molding quality.Finally the important order of the effect on the efficiency was obtained as C,B,A,and the optimal combination is C₂B₃A₁.The important order of the effect on the quality was obtained as C,A,B,and the optimal combination was C₁A₁B₃.The final validation test was conducted by the Fused Deposition Molding (FDM) 3D printer.The results showed that the obtained combinations were conducive to the better quality and efficiency.

The Body Control Module (BCM) is an important part of the car,the design of BCM bracket should meet fatigue life requirements under random changeable conditions as vehicle driving.The 3D modal was created by Catia and the finite elements were meshed by Hypermesh,so that the reasonable Finite Element Analysis (FEA) modal has been established for analysis.The results verified that the random vibration FEA fatigue analysis is necessity and validity for BCM bracket.Finally,the BCM bracket has been optimized,and the random vibration FEA fatigue of the optimized bracket has been analyzed.

In NC milling surface machining,the relation curved surface formed by two two curves is often met.Such as the use of CAD software on the surface numerical control programming,the program is lengthy,the adjustment is not convenient,it can be used in the way of macro programming.Takes a part of curved surface processing as an example to introduce the idea of the preparation of the macro program and related instructions,and to process the macro program as a template.In the preparation of similar parts surface processing procedures,can be a template based program,adjust and modify the part of the program content,thus completing the new NC Macro program written to realize parametric programming.Through case programming,summed up the parameters of the program of attention.Because of machining curved surface using parametric programming macro program,improve the programming efficiency,in the production can be used to promote the use of.

In view of the problems of low machining efficiency,high machining cost,and bad machining quality in complex shape product engraving and milling because of the complex tool motion caused by the complex shape and small tool is easy to break,an optimization method with cutting tools as the core for engraving and milling complex shape product was proposed.First,the characteristics of complex shape product and the special characteristics of cutting tools were analyzed and a cutting tools model of complex shape product engraving and milling was put forward.On this basis,the model of processing parameters optimization in cutting tools determined condition was established.Then,the particle swarm optimization algorithm was introduced for the optimal solution of the model of processing parameters optimization in cutting tools determined condition.Finally,an optimization case was given to verify the feasibility and practicality of the proposed method.The above method has been applied to the actual production,and shows a good application prospect.

Tool state monitoring in manufacturing process is an important step to ensure accurate,efficient and safe machining of workpiece.The basic principle of tooling state diagnosis method based on Deep Neural Network (DNN) is described.Based on the study of DNN structure and training algorithm,a tool state recognition method based on DNN is studied.The cylindrical turning process of CK6143\1000 CNC lathe,KC5010 turning tool and austenitic stainless steel 304L is taken as the experiment object,and the tool image is collected to carry out experiment.A set of DNN for tool state recognition is realized.The result shows that the accuracy of tool state recognition is over 98 %,which proves the feasibility and validity of the method and has good engineering application value.

Magnetron sputtering technology is widely applied in the decorative plating of high-grode products. The Ti/TiN/TiCN composite films were deposited by magnetron sputtering process on the substrate of aluminium alloy.The TiCN films with different colour were prepared by changing the processing parameters of nitrogen flow rate,acetylene flow rate and deposition time.The ways to improve the microhardness and bonding strength of the composite film and to improve the decorative and protective properties of the aluminum alloy surface are also discussed.The results show that by controlling the process parameters,such as nitrogen flow,acetylene flow,sputtering time,the TiCN film presents certain color,such as “luxury-gold-colored”,when the compositefilms thickness at 1.5 microns,the composite films pencil hardness of 6 H,adhesion reach level 1,meet the test standard of 3C industry.

The forming and assembling process of self-lubricating joint bearing is a hot research topic in recent years.Study the reasons why the inner and outer rings have large clearance in the spin-forming test.Explore the method to reduce the large gap in the spinning process.And explore whether the spinning method can improve the gap uniformity of inner and outer ring simultaneously reduces damage to the inner ring and the liner.Using LS-DYNA that is the finite element analysis software to research on the spinning forming process of outer ring of self-lubrication spherical plain bearing with integral outer ring,by optimizing the outer ring blank shape and the contour curve of the rotary wheel,combining with the related mechanics theory about elastic-plastic and the advantages of spinning forming that has uniform deformation,small forming force and easy to control

The process of Electrical Discharge Machining (EDM) can be considered as the results of accumulating of many single pulse discharges.In EDM,theaccuracy of plasma passage could be well reflected by studying single pulse discharge characteristics,and the characteristics of the discharge craters can be studied facilitately.Therefore,a single pulse generator has an important role in the fundamental research for EDM.Although many studies about single pulse in EDM were carried out,however,the designs of the single pulse generator were less reported.The design for a dependent single generator was developed with an AT90S8535 microcontroller as acore chip.The design of the main oscillator control circuit,a power switch drive circuit and a detection circuit were introduced.The discharge tests of the single pulse generator in air were conducted and the discharge voltage waveforms were achieved 5、50、180、400 and 800 μs,thus,the feasibility of the generator was verified.

In order to decrease the influence of thermal errors on machining precision of machine tools and to improve the prediction accuracy of Grey system Model(GM),the Improved Chaotic Particle Swarm Optimization (ICPSO) is introduced into the grey system model.One improved chaotic particle swarm optimization based grey system model is proposed to model the thermal errors of the machine tools.Firstly,the mapping of between particles of PSO and the parameters of grey system model is developed.Next,the Logistic map of chaotic theory of ICPSO initializes the location and velocity of particles.The optimal parameters and input set are obtained by optimizing search with ICPSO.Then,the model based on ICPSO-GM is established to predict the thermal errors of machine tools.The simulation shows that the thermal model of ICPSO-GM has the higher prediction precision than GM and Artificial Neural Network(ANN).The results indicate that the proposed ICPSO-GM can effectively realize the prediction of thermal errors of machine tools.

In order to satisfy the perceptual cognition of users and designers for product styling,an innovative design method of product image styling based on recognition degree and interactive partheno-genetic algorithm was presented.Firstly,the target image and the representative product samples were determined,and the product image was investigated and analyzed.Then,the selection mechanism of product image styling was established based on the product image recognition degree.Finally,the innovation design system of product image styling based on interactive partheno-genetic algorithm was set up,and the selected product samples were used as parents samples to get the optimal design products.The result shows that the method can provide effective assistance and support for product styling design.

The key factors of bright annealed line equipments such as burners,communication to the furnace and driving system,bridle No.4 and power supply are analysed and controlled by the six Sigma method based on the collected information on internal and external demands.The PID integral value and ratio value of driving system were found out after the DOE experiment.The hardware and software of the key parts are improved,the electrical and mechanical equipments are running stably than before,the accuracy of the equipment is guaranteed,the delay time is reduced,the equipment availability is increased.

The method of CFD numerical calculation was conducted for carrying out the study of a fuel pump inner flow field.As SST k-ω calculation model and multiple reference frame technology applied,while outflow and volumetric efficiency were chosen as the optimization goal,the structural parameters of fuel pump impeller was optimized with multi-objective genetic algorithm and adaptive weight method.The negative optimization phenomenon of the individual target in the process is solved.Comparing the results of outflow and volumetric efficiency data before and after improved optimization,the outflow is increased by 3.90 %,the volumetric efficiency is increased by 0.53 %,respectively.This kind of method can provide a suitable referenced solution for structure optimization design of pump.

In order to improve the frequent replacement of the cutting reducer applied on the colliery,based on the demanded of the strength,transmission performance and geometry to set as the restrictions,the design variable such as gear module,teeth and tooth width were seletcted as the design variable,and the parameter such as the maximum degree of coincidence,the minimum slip ratio and volume were set as the objective function.the particle swarm optimization of bionic intelligent calculation was used to optimization the design parameters of gear.Based on the optimization of structural design reducer,the test of installed experiments to verify the optimization results,and it provides a reference to solve practical engineering problems.

Violent vibration occurred in the process of test run on laying head which a plant designed.Analysis of vibration test and spectrum was carried out.The modal of the rotor was analyzed based on FEM.Critical speed was calculated.Unbalanced response was analyzed by SAMCEF Rotor.Equilibrium planes were calculated combined with the structure of laying head,which provide reference on dynamic balanced trim of rotor.The trim of the rotor was done by dynamic balance theory of rigid rotor,which has obvious advantages over the field dynamic balancing method.

The chain is the core component of NSE elevator.The chain fracture brings to users the larger production costs and safety concerns.It is of great importance to improve the service life of the chain by research the measures and methods.In view of the chain failure modes,to analyze the failure reasons,the chain structure had been analyzed by finite method on the static strength analysis.It was proved the structure design of the chain satisfies the requirement of static strength.The S-N curve of the parts was calculated,The fatigue life of the chain was analyzed further,It is concluded that the main causes of failure is fatigue damage on the chain.The fatigue analysis results are very close with the average service life of chain plate in the actual production,it was showed that the fatigue simulation is effective,and the corresponding improvement measures was put forward from the aspects of manufacture process and use.After the implementation of improvement measures,the service life of the chain has increased dramatically in practice.Therefore,when the experimental research is not carry out objectively,it is feasible to obtain more accurate simulation of the fatigue life test by fatigue analysis for the parts.

In order to further analyze the connection performance of cone interference fit joint,taking the cone interference fit joint of a diesel engine crankshaft vibration damper for example,the combining diameter expression of cone interference joint was deduced and the formula of contact pressure and the torque transmit of interference fit was obtained through establishing interference fitted theory model.The interference fitting of crankshaft and the main hub was simulated and analyzed by using ANSYS.The effects of fit tolerance,coefficient of friction,rotational speed and the contact stress distribution on the mating surfaces were discussed in the numerical computation.The result showed that the effects of fit tolerance and rotational speed are obvious;the fit tolerance has a linear relation with the contact stress and the coefficient of friction has little effects for the distribution of contact pressure at the crankshaft resting.

Hydro-mechanical continuously variable transmission is a new kind of transmission,with the features of continuously speed regulation and high efficiency.According to a new type of hydro-mechanical continuously variable transmission,the design of hydraulic control system is carried out,through the analysis of the open hydraulic circuit and the closed hydraulic circuit,combined with the actual control needs of transmission,the closed hydraulic system is more suitable for the transmission. Using the AMESim for the modeling and simulation of the hydraulic system respectively,by analyzing the pressure-flow characteristic of the pump-motor system,the system power split-flow and the efficiency characteristic of the system both of the open and closed circuit hydraulic system,confirmed the rationality of the closed hydraulic system.

Automobile cover parts mold damaging because of improper operation,foreign body into mold or jams waste of mold in stamping process.By reinforcement plate mold damaging of rear longitudinal beam as an example,introducing the application of reverse engineering technology in mould repairing.Is proposed based on the three reverse CAD/CAE software function of their respective advantages for fracture set piece of repair process.First getting point cloud data by three-dimensional scanner,optimizing the point cloud data and the grid by the Geomagic Studio software,then using Geomagic Design Direct software for surface reconstruction,finally through the Geomagic Qualify software testing the precision of the reconstructed surface.Practice results show that this method can improve the accuracy of repair mould,reduce the production cycle.

Research on typical faults of piston engine,a multi-signal fusion diagnosis method based on wavelet packet analysis and Kernel Principal Component Analysis (KPCA)is proposed.First of all,wavelet packet is used to decompose the original vibration signal,and the fault feature in frequency domain is extracted.Then combined with the vibration signal in time domain and thermal parameters such as unit exhaust temperature,using KPCA to obtain the sensitive characteristics,which will reduce the dimension of parameters.Finally,the Support Vector Machine (SVM)is used to complete the automatic classification of faults.The method is applied to the actual faults of piston engine,and it turns out to have high diagnostic accuracy,which confirmed the validity of this method for feature extraction and fault diagnosis