Applied Mechanics and Materials Vols. 602-605

Abstract: Based on structure and working principle of semi-active interconnected air suspension, whole vehicle dynamic model including interconnected air springs system model, damper model, vehicle body and tire model is established. The changes of parameters such as connect pipe diameter, unilateral or bilateral excitation input phase difference that have effect on the air spring stiffness characteristic are simulated when air springs in the interconnected condition. The simulation results show that, interconnection of air springs can reduce the stiffness of air spring, and vehicle ride performance and riding comfortable performance can also be improved effectively.

Abstract: Features of the piston reciprocating motion is a high commutation frequency, small displacement, the impact force. Requirements of the piston movement is able to adapt quickly to change. Reducing the resistance movement of the piston will be able to make more flexible movement of the piston .The seal with mating surfaces can reduce the resistance movement . The gap of mating surface of the piston rod formed hydraulic oil spill. Mating surface seal problem is that the oil leakage is larger。Piston movement way of hydraulic vibrator is a kind of variable frequency and variable amplitude, in the form of constant flow. The form of the oil cylinder and the piston movement is the same. The cylinder as the output component of hydraulic vibrator output movement is to reduce the leakage .

Abstract: When the wheel of the wheel edges reducer working, single tooth meshing and bidentate meshing alternately, Gear meshing dislocation, mutation load, speed fluctuations, engaging-in and engaging-out impact will inevitably appear. This paper take the wheel hub reducer based on 60t AC drive articulated dump truck as the research object, use romaxdesigner model and motion simulation analyze the wheel edges reducer. through the analysis obtain the stress and the longevity of gear. According to the simulation results correct the gear for the purpose of improving the bearing capacity of the gear and reducing meshing noise.

Abstract: The mechanical analysis of the lifting beam for heavy engine compartment was analyzed by traditional theoretical mechanics and material mechanics methods, and the basic structural shape of the lifting beam was design. The FEM intensity analysis, strength check and the structural optimization design of the lifting beam were carried out by making use of the software of ANSYS Workbench, and the reasonable structural shape and size of the section were got. Through optimization design, the material was saved, the weight of the lifting beam was lessened, and the economic benefit was improved.

Abstract: building bearing pressure detection has been one of the hot issues in the field of architecture research. Traditional methods for building bearing pressure detection are to calculate the bearing area, which is difficult to reach the accuracy in point level. It is primarily because the large range of signal distribution, resulting the weakened correlation signal. To solve this problem, an opening reinforcement method is proposed based on pressure - area stress calculation. Compared calculation between building bearing pressure and area is performed in this method to ensure that the search area is minimized, thereby obtaining an accurate supporting point of building bearing pressure. The simulation experiment shows that the effect of the method for locating the building bearing pressure point calculation is better, and it has a higher accuracy.

Abstract: The traditional braking model does not consider the impact of drivers' visual distance error, which leads to deviation in determining the distance between vehicles, and therefore effective braking model cannot be built. In order to solve this problem, the paper proposes a modeling method reflecting the relationship between psychology of night vision and braking distance to get the optimal braking reaction speed thus realizing intelligent emergency brake control. The experimental results show that the model takes the relationship between psychology of night vision and braking distance into consideration, increases the braking reaction speed of the drivers, and has high robustness.

Abstract: Several arc models representing a disconnector’s closing operation in a 252kV gas insulated switchgear (GIS) are implemented with a computer program ATP/EMTP to simulate very fast transient overvoltage (VFTO). Arc models are used as black box models in connection with a test circuit. Theoretical bases, formulas and realizations of these models are described. Arc models’ parameters are mainly pinpointed by fitting their simulation results with VFTO waveforms measured in a real 252kV GIS test setup. Comparisons between arc models’ simulation results and measurement indicate that dynamic arc models based on Cassie and Mayr theories give more realistic results with particular regard to VFTO’s peak value and frequency spectrum.

Abstract: Improving the machining precision mechanical manufacturing field is an indispensable chapter topic. In this analysis focuses on the rail straightness, process system stiffness, milling way, cutting layer parameters, tool wear, thermal deformation of the workpiece spindle axis traverse peace pliers jaws of irregularities in the machining precision flatness influence. Milling cutting process parameters of different layers, different milling heat, different deformation of the workpiece, resulting flatness error is different. Different milling methods and different milling force also affect flatness errors. Therefore, the workpiece machining pass these factors need to be considered. And proposed a solution for uneven of flat-nose pliers jaws and surface of workpiece.

Abstract: To inspect and forecast the failure of the gearbox equipment, the dynamic models of tooth surface flake are established. The thesis explores the gearbox nonlinear dynamic characteristic caused by tooth surface flake, and researches the variant joggling stiffness caused by flake failure,analyzes the primary resonance of the flake failure. By the singularity analysis, the fault causes the bifurcation mode of the gear system, which shows effect of the generation and evolution of the fault on the dynamic response of the system. Using the experimental device,the theoretical models are tested and verified.

Abstract: Multi-objective genetic algorithms (MOGA) is broadly used in the engineering problem. . Combined the multi-objective genetic algorithms (MOGA) with finite element method (FEM), a new kind engineering optimization method is established. This optimal method takes fully advantage of the unique feature of genetic algorithms that the optimal solution is achieved by a rapid global search and takes advantage of the unique features of FEM that the computation is accuracy. This method can solve multi-objective problems with more complex constraints in the engineering. The procedure is developed by VC++. Temperature difference of H-beam section has great influence on the residual stress of H-beam. In order to reduce the temperature difference of H-beam and make the microstructure of H-beam uniform, the cooling parameters of H-beam after rolling are optimized. The new kind of optimization method MOGA combined with FEM is used to handle this problem. The better optimization result is obtained.