Abstract:To obtain the distribution characteristic of contact stress and the bulk temperature on the surface of herringbone gears, parameter modeling of gears was carried out by parametric design language. A numerical simulation was given to calculate the contact stress field and the steady thermal field by combining heat transfer theory, tribology theory, and mesh theory. The distribution of contact stress, the bulk temperature and heat flux also were analyzed. The analysis results show that the distribution of the load along the contact line possesses regularity. The heat flux along the tooth depth direction decreases first and then increases. The effect of thermal conduction of the tooth is stronger than that of convective heat transfer. The conclusion indicates that the finite element emulation method can be used to estimate the transmission performance of herringbone gears.

Abstract:A new distributed equipment condition monitoring and fault diagnosis network system based on an RS485 field bus and an industrial ethernet was designed for the main drive system of a hot strip mill. The system structure and composition were studied. The following problems were resolved: communication of an intelligence data acquisition module with RS485 interface; communication between a server, clients and a light emitting diode; and point to point communication between a programmable logic controller and server. Realtime signals of 24 radial runout, 12 axial drifting can be synchronously acquisitioned and stored in a database. System operation is satisfactory and can be used to identify the causes of rolling mill halt and transmission slip brake, and to improve sheet metal quality.

Abstract:Taking the influences of joggle forces and gravity into account, a static model of a highpower marine gearbox was established using the finite element method. The gearbox workload capacity was calculated in four working states. Gearbox strength and structural rigidity were analyzed. Combining theories of optimization and reliability design, the gearbox optimization model was obtained based on the intensity principle. To insure a safe structure, optimization designs were put in practice to improve the gearbox structure. As a result, the gearbox weight was reduced 1 060 t by structural optimization. The strength of the improved gearbox is more symmetrical and the structure of the improved gearbox is more reasonable than previoius designs, indicating the method has certain theoretical and practical engineering values.

Abstract:Wind turbines operate in harsh environment with transient and variable working conditions. As a result, wind turbines are complicated, nonlinear, uncertain systems. Modeling and analysis of these systems are crucial to their design. Based on MATLAB, a new dynamic simulation model of a stalled wind turbine was presented. The blade element momentum theory and the statespace method were programmed into MATLAB/SIMULINK to calculate wind turbine aerodynamic performance. The generator was also modeled in MATLAB/SIMULINK, taking the coupling between the generator and the rotor speed into consideration. Based on the proposed MATLAB model, an analysis of a 600 kW wind turbine was carried out. The calculation values were compared with the measured data. The results indicate the correctness of the proposed MATLAB model. The simulation model can be applied to optimize design and control of stalled wind turbines.

Abstract:This paper proposed a new method called a “sequential fuzzy neural network” to diagnose gear equipment failures automatically and precisely. The symptom parameters in time domain, by which each gear equipment failure can be detected sequentially, were selected according to values calculated from the signals measured in each gear condition. To express the relationship between the gear condition and the symptom parameters, the probability density functions were translated to possibility distribution functions by possibility theory. The diagnostic process can be carried out automatically by a neural network combined with sequential fuzzy inference. Examples of practical diagnosis are shown to verify the efficiency of this method.

Abstract:Aiming at a muffler of a 400 all terrain vehicle(ATV), a vibration model and an acoustics model of the muffler were built by finite element method(FEM). The vibration and acoustics characteristic analysis of the muffler are carried out according these models, it shows the 3D model is exact and it is possible to generate regeneration noise. Acoustics model can help to know further about the characteristic of each chamber and intention of the designer. According the demand of factory, some projects of improvement are offered. The final result of road test proves that he improved muffler is feasible.

Abstract:A forecasting model for logistics demand was presented to overcome the limitations of single goal forecasts of logistics demand and forecast data complexity. Based on the forecasting evaluation index and pretreatment of rough set theory, a multiinput and multioutput wavelet network (MMWNN) model for forecasting multielement regional logistics demand was studied. The network configuration was confirmed using the stepwise checkout and iterative gradient descent methods. After rough set reduction, the evaluation index was used to forecast the multielement regional logistics demand. The results of the numerical example indicate the feasibility and effectiveness of the model.

Abstract:In order to meet the performance demands of train lorry, a die forgingdrawing method based on structure features analysis was proposed to form the LA break beam frame. The finite element method was used to simulate a series of dieforging processes and the drawing processes with different parameters. The optimum crosssection shape of the performing die was obtained from these simulation results. It is found that local backflow of the metal is the primary cause of necking defects in drawing. Furthermore, the best drawing speed is determined to be from 87 mm/s to 96 mm/s. The results of trial manufacturing and product detection indicate that employing a die forgingdrawing process to form the monobloc break beam frame is feasible.

Abstract:Regional manufacturing information engineering industries are extremely large and complex systems. Based on the implemental integer effect and an evaluation requirement of regional manufacturing information engineering, we analyzed the objectives and characteristics of regional manufacturing information engineering, proposed a multiple evaluation index method of regional manufacturing information engineering. Based on a multiple integration evaluation method, we built a model to evaluate regional manufacturing information engineering. We proposed a measurement model for regional manufacturing information engineering based on multilevel fuzzy comprehensive evaluation. Our quantitative research regarding the implementation effectiveness of regional manufacturing information engineering was based on fuzzy quantitative indicators. The model was grounded on collecting indexes of regional manufacturing industry information engineering, and used a fuzzy matrix to normalize the assessment results to a single fuzzy comprehensive evaluation level. Measurement was carried out step by step. Multilevel comprehensive evaluation results for a regional manufacturing information engineering industry were obtained. The validity of the model was shown through application practice.

Abstract:In an effort to address the high risks and qualification demands of test drivers, a vehicle model and a driver model were built based on ADAMS/CAR, an advanced block of ADAMS. The steering efforts test procedure was designed according to the national standard GB/T 6223.5—1994. A virtual test was performed in ADAMS, and the results calculated. The results show that the driver model possesses a strong capacity to charge the vehicle model. The virtual test results satisfy the evaluation index, indicating the virtual test can be used to test and improve vehicle performance.

Abstract:To address the issue of whether it is rational to define damage variables through the degradation of elastic modules, we essentially clarified which material module should be used to describe the damage variables in unidimensional cases, and pointed out that the reference undamaged working state of material was needed firstly in order to measure the degree of damage if the strain equivalence hypothesis was used. We maintained it was baseless to consider the linear stressstrain working state as an undamaged reference state. We deduced a rational definition of elastic and elastoplastic damage variables. We stated that the degradation of an unloading module can be used to define the damage variables. To illustrate the definition of damage variables, we presented an example of establishing a damage constitutive equation of concrete in compression, validate the elastic strain equivalence hypothesis, and provide an appropriate approach for establishing a damage constitutive model.

Abstract:A finite element model based on the flexibilitymethod and a fibersection model of nonlinear beamcolumn elements was adopted within the OpenSees framework. A typical multistory reinforced concrete 3D frame designed in accordance with the Chinese building code and a representative plane frame parallel to the Xaxis were used as examples. The relationships of the responses obtained from the plane and 3D models were studied by comparing global and local seismic responses of the frame, and by taking the responses of the 3D model under unidirectional earthquake action as a medium for comparison. Because the results show the global responses of the plane model are similar to those of the 3D model, it is reasonable to replace the 3D model with the plane model when examining global seismic responses. The local responses are evidently different. For the plane model under unidirectional action, numerous plastic hinges develop at the beam ends. Many more plastic hinges at column ends exist than in beams for the 3D model under bidirectional action. Column ductility demands obviously exceed those of beams. The frame tends to develop a column sway mechanism, implying that simplified plane analysis model significantly underestimates the seismic responses of the 3D frame column.

Abstract:Based on structural deformation analysis, we developed calculation models of externally prestressing tendon stresses increments for simply supported beams on service loads. The Windows program SICPEM for calculating stress increments, based on energy principle, was programmed using the objectoriented method. Six beams results, tested by Tan, and the free length of externally straight tendons were recomputed by the program. The ratio of computed results to test results is 0.895, and the standard deviation is 0.013. Furthermore, the free length of externally straight tendons, for which the secondorder effect can be ignored safely, is ten times beam depth. This coincides with the reference literature.

Abstract:We calculated the elasticplastic finite element method (FEM) of three adobe walls and three composite adobe walls of differing thicknesses, and analyzed their lateral resistance capacities, crack shapes and ductility. Based on the results, a simplified formula is put forward for calculating the lateral resistance capacities of composite adobe walls. The formula provides a basis for designing composite adobe walls. In addition, we estimated the seismic effects of earthquakes of varying degrees and frequency of intensity (basic and rare intensity) on composite adobe walls. The results indicate that traditional adobe walls with timber columns and beams can satisfy the criterion of rare earthquakes of seismic zone 9. The results provide a basis for the transformation and seismic reinforcement of traditional residential buildings in Xinjiang.

Abstract:To address the shortage of data regarding extreme winds in P. R. China, we examined Xiamen, located on the southwestern Chinese coast, as an example. We used the Batts wind field model and the MonteCarlo method to simulate extreme wind speed distribution models and to predict maximum wind speeds in different recurring periods. The simulated results coincided with the experical distribution function. Comparing the numerical analysis results of different extreme distributions, such as the Gumbel distribution function, the Frechet distribution function, the reverse Weibull distribution function, and the Generalized Parato distribution function, shows that the reverse Weibull distribution function provides the most precise prediction of maximum wind speed for a onehundredyear return period, while the Frechet distribution function significantly differs from the results of all the other distribution functions. The extreme wind speeds of different return periods are estimated.

Abstract:Vibrationresistance can be incorporated into blasting designs to avoid damages caused by the excavation of largespan tunnels in busy urban areas, but only by basing excavation design schemes on actual situations. In view of the actual situation in the Jahua tunnel in Chongqing, P. R. China, research was conducted to identify a relevant explosion scheme. The research was based on theoretical analysis and insitu testing. Face step excavation was considered in the broadening band A, and upper drift excavation was adopted in broadening bands B, C, D and E. We simultaneously proposed selection criteria for smooth blasting parameters and the construction layout of broadening band B. Based on a regression analysis of the blasting vibration monitoring results, a spread orderliness of blasting vibration was drawn. Explosion parameters optimization measures were put forward, selected from the maximum charge quantity, millisecond blasting, reasonable blasting time difference, and the excavation plan. Field testing achieved satisfactory results. These findings will play an important role in guiding excavation blasting construction of tunnel projects and assuring the safety of ground buildings.

Abstract:Nonhomogenous settlement will occur while the expressway is constructed on soft ground. The differential settlement can cause the bigger additional stress inside the asphalt pavement structure accelerating bituminous pavement destruction. Therefore,we must choose reasonable pavement structure when constructing road on soft base in order to reduce the influence on surface layer structure from the differential settlement. Based on ABAQUS finite element method and through analysis, this article draws the conclusion that establishing unbound graded aggregate sandwich structure under the asphalt pavement structure can effectively reduce the horizontal additional stress of the stresscontroled layer and better prevent crack reflection which is beneficial for constructing the asphalt pavement structure on the soft ground.

Abstract:Simulated experiments of grounding grid corrosion were conducted based on two 220 kV substation models. In initial diagnosis, the measurement nodal points were planned to great span, small piecemeal, and large piecemeal jointing fixed points. A comparative study of the three measurement plans was carried out. The results show that the large piecemeal with fixed points had the best performance and could be used as a practical method for diagnosing grounding grid corrosion.

Abstract:A novel method simulating a brushless direct current(DC) motor was presented, based on principles of hybrid system modeling and finite state machine theory. Brushless DC motor control mainly focuses on controlling the on/off condition and power switch duration. Modes of control therefore can be defined by corresponding states, and the states can be combined as a finite state machine. This approach uses the popular Simulink/Stateflow simulation method to control brushless DC motor loops. A threephase brushless DC motor was analyzed to illustrate the process of model building with Simulink/Stateflow. The analysis demonstrates the feasibility and validity of the proposed method.

Abstract:It is necessary to predict electromagnetic compatibility (EMC) for electronic equipment and systems. We proposed a fast EMC prediction approach via artificial neural networks (ANN). By choosing relevant electromagnetic interference parameters as the input prediction features, a back propagation (BP) neural network was used to construct the mapping between the input prediction features and the electromagnetic disturbance response of the sensitive system. The EMC fast prediction BP model was trained and tested by sample sets generated using an electromagnetic computational method. We used this method to predict the crosstalk coupling between two wires. The experimental results show the effectiveness of the proposed method.

Abstract:Through the analysis of the equivalent resistance method, a limitation of the equivalent capacity method was presented. When the direction of power at the feeder source end was changing, the equivalent capacity method for handling small generations would produce a large power loss calculation error. An improved calculation method, one not based on a single equivalent resistance, was proposed. In this method, one day was divided into several periods (such as 24 h), so that the direction of power at the feeder source end for each period does not vary. The equivalent resistance and energy loss in each period were calculated. The sum of all energy losses provided the daily energy loss total. Numerical examples were used to verify the improved method.

Abstract:The conductivity of a TiO2 cathode in the FFC process was studied by sintering and electrolyzing experiments. Sintered TiO2 cathode and electrochemical reduction of TiO2 were measured using Xray diffraction. Results show that changing the energy band structure of TiO2 via hightemperature sintering can cause electric conduction vacancy. An electric double layer can be formed in molten salt. Ionization of oxygen atoms leads to formation of TiO2x ionic structures. The ions infiltrate to the electrode in molten salt, increasing the number of conduction ions. The electrolyzing process proceeds smoothly, based on the integrated mechanism of activating the TiO2 cathode. The activated TiO2 cathode can be obtained by forming electric conduction vacancy at hightemperature sintering, the TiO2x ionic structure by electric double layer, and ions infiltrating to the interior of the electrode.

Abstract:The SiO2 ultrafine powder with high porosity and large specific surface area was prepared from sodium silicate and sulfuric acid as raw materials by parallel feedin chemical precipitation method. The basic performance of SiO2  powder had been characterized by means of BET、TGDTA and laser granularity analysis. Effective factors, including ways of materials feedin, sufactants and heating procedure were also investigated. The results indicates that the specific surface area of the prepared SiO2 powder is 823 m2/g, and the cumulative pore volume is 1.438 cm3/g.

Abstract:A supercritical CO2 fluid extraction (SFE) method was developed to extract isoflavone. A uniform design was used to investigate the effect of the extraction pressure, extraction time, extraction temperature, and medicinal materials granularity on isoflavone extraction efficiency. The optimum conditions of extraction were as follows: 45 MPa extraction pressure, 50 ℃ extraction temperature, 4 h extraction time, 40 eyes medicinal materials granularity, and the extraction efficiency was (0.361±0.012)%.