Advanced Materials Research Vol. 510

Abstract: In order to make the mass distribution of the wheel set symmetrical about the axis of the wheel axle, which is able to remove the periodical exciter source and many consequences coming from it, including having negative effect on the stationarity and stability during the running of the train, shortening the lifetime of the wheels, bearings and many other parts of the train, design a set of balanced device to regulate the mass center of the wheel set. The set of device collects data by relevant detection devices in order to find the mass distribution condition, and then regulate the circumferential positions of the objects with a certain mass in the tapered groove which can make the mass distribution of the wheel set symmetrical about the axis of the wheel axle. The device has many advantages, such as simplicity, high precision, excellent regulating effects, and, at the same time, conquers the disadvantages of many other ways. For the time being, the means to solve the problem are mainly Adding Weight Method and Removing Weight Method, which both cause physical damage to the wheel. Furthermore, these two methods have a lot of disadvantages, such as low stability, limited effect, limited repairing numbers and high labor strength. The device not only conquers these disadvantages of the two methods, but also has many advantages, and in the future, it can be automatically controlled by microcomputers. Wheel sets are very essential to the running of the train, whose quality has outstanding effect on the safety and quality of the running of the train, especially in the condition that trains run faster and faster, which requires wheel sets to meet higher standards on dynamic balance, especially for new high-speed bogie. Thus, the device has a large economy benefit and society benefit.

Abstract: Contact force is a complicated force in practical problem. By using the powerful function of ADAMS in dynamics analysis, we can solve it in a comparatively accurate way. Since a number of parameters are involved in the simulation in ADAMS, the initialization of them has a great influence on the simulation. Aiming at the contact force between wheels of wheel chair and ground, the value of the parameters was calculated and analyzed in this paper. The main research object in this paper is the parameter of the ADAMS/Solver. The result of the dynamics simulation is also used to test whether the parameters are defined properly or not. With this method, we find a better way to define the parameters in ADAMS.

Abstract: This paper introduces a new type of automatic steel wire bundling machine for bundling process, which includes a hydraulic action process, mainly do some researches on the hydraulic control system. The system chooses PLC as the core control component, puts forward the hardware of control system and control flow. Eventually we have been designed the control program.

Abstract: In order to reduce the catastrophic optical damage ( COD ) in the cavity surface of the traditional GaAs-LDs, this paper proposed the use of AlN film prepared as a non-absorbing window near the cavity surface of GaAs-LDs. In order to validate its feasibility, first of all, we prepared AIN film with different thickness on GaAs chips by reactive magnetron sputtering technology, and then, the PL spectroscopy of AlN / GaAs surface was acquired, the residual stress of the structure was calculated in accordance with the wavelength drift of GaAs intrinsic peak with the change in testing temperature.The experimental results show that the compression stress on GaAs chip is obvious when the thickness of AlN film is above 0.8 um. After the GaAs chip is subjected to compressive stress, the band gap will be widened,so the Eg of the active region near window area of GaAs-LDs will be wider than one of the active region inner the cavity, so that when the photons pass through this area, the absorption will be reduced, thereby forming non-absorbing window,therefore, the experimental validated that the AlN film used as the non-absorbing window of GaAs-LDs is feasibility.

Abstract: An finite element model of orthogonal dry cutting with separate line is established according to the constitutive relation of large thermo-elastic-plastic displacement and the principle of virtual work in metal plastic deformation process,. The influence of cutting depth on residual stress was simulated for materials GH4169 with high speed. The residual stresses are analyzed on the machined surface and subsurface. The result shows that tensile residual stress of the machined surface is minimum value when the cutting depth is 0.2mm. the deeper is the depth of cut, the large the augmentation of compressive stress on the subsurface, which proves foundation for cutting process of dry-machined difficult-to-machine material with high speed and make it more efficiently to control the integrity of the machined surface.

Abstract: The granular model which is fit for discontinuous bodies is applied to powder injection molding. The powder is regarded as discrete particles which are immersed into binder. The powder three-dimensional flowing in powder injection molding has been simulated based PFC. The results show that the filling rate of granulars is anisotropy and injection molding is always filled in the central region of cavity where resistance is smaller. But the angular area where resistance is large often filled be the end, even if it is close to the center of pressure.

Abstract: The influence of the clearance in the joint must be considered in the modeling and dynamic analysis for the mutibody mechanical systems. The model of the planar revolute clearance joint is built on the base of the clearance vector approach and the continuous contact approach. Furthermore, the friction is included through the modified Coulombs friction law and the lubrication is introduced into the model, with the Reynolds equation employed to evaluate the hydrodynamic forces. A slider-crank drive system of a screen printing machine with a clearance joint is researched as the example, whose dynamic characteristics are simulated by the software ADAMS. It is shown that the clearance has affected the dynamics response of the system and the lubrication is effective to deaden the impact.

Abstract: Through analysising the structure of the Remote Control Weapon Station (RCWS) and simulating shooting on the move to obtain the characteristics of the muzzles vibration, we use the three-dimensional modeling software SolidWorks and dynamic analysis software RecurDyn to build the integrated dynamic model with road, cars and guns. Meanwhile we verify the correctness of the model. At different speeds and different road conditions we did the dynamics simulation of the Remote Control Weapon Station for the continuous firing on the move and obtained the vibration characteristics of the muzzle, which provided a reference for the operator to control the Remote Control Weapon Station in more stable conditions and improved shooting accuracy.

Abstract: In fluid mechanics, how to solve multiple solutions in ordinary differential equations is always a concerned and difficult problem. A particle swarm optimization algorithm combining with the direct search method (DSPO) is proposed for solving the parameter estimation problems of the multiple solutions in fluid mechanics. This algorithm has improved greatly in precision and the success rate. In this paper, multiple solutions can be found through changing accuracy and search coverage and multi-iterations of computer. Parameter estimation problems of the multiple solutions of ordinary differential equations are calculated, and the result has great accuracy and this method is practical.

Abstract: Currently, researches on anti-cracking performance of asphalt concrete overlays on old concrete pavement for fatigue are still in the early stage of explorations and trials. The reflective crack simulation tests of bending and shearing styles with six asphalt overlays were carried out in order to evaluate the anti-cracking effects of different kinds of anti-cracking materials. It is suggested that Sampave modified asphalt mixture with independent development has excellent anti-cracking performance for fatigue, which provides an experimental reason for extending the anti-cracking technique in stress absorbing layers. Although anti-cracking performances of glass fiber grid and tricot geofabric reinforced composites are better, it is not as good as the one of Sampave. And the effect of paving asphalt concrete directly on old cement concrete pavement is worse.