Applied Mechanics and Materials Vols. 26-28

Abstract: Photoelectrocatalytic (PEC) degradation efficiencies of a suspended TiO2 and Ti electrodes composite system in different ammonium salt solutions were investigated. Electrolyte type and concentration as well as the applied potential on the Ti electrodes had significant effects on photoelectrocatalytic degradation and electro-degradation efficiencies. PEC degradation and electro-degradation of methyl orange increased with increasing applied potential and electrolyte concentration. PEC degradation is much more powerful than electro-degradation. PEC degradation efficiency in (NH4)3PO4•3H2O solution is the highest 93.4%, whereas the efficiency in NH4Cl solution shows the worst 73.1%, which is even less than that of photocatalytic process alone. PEC degradation efficiencies in (NH4)2SO4 and NH4HCO3 solutions are 88.8% and 85.9% respectively, indicating no noticeable improvement compared with photocatalytic process.

Abstract: The forming of tailor-welded blank is an important technology to body light weighting. While it is difficult to predict the forming limits of tailor welded blanks with different base materials or thickness. For the expanding experiments, an analytical method to predict forming limit height of tailor-welded blanks is established based on the deformation characteristic and plastic theory, and verified by simulation results. This method is not only provided a path to predict forming limit of tailor welded blanks but also provided references to the design of tailor weld parts.

Abstract: The machine-part cell formation is a NP- complete combinational optimization problem. Past research has shown that although the genetic algorithm (GA) can get high quality solutions, special selection strategy, crossover and mutation operators as well as the parameters must be defined previously to solve the problem efficiently and flexibly. In this paper, an improved permutation code PBIL is adopted to solve the machine-part cell formation problem. Simulation results on five well known problems show that the PBIL can get satisfied solutions more simply and efficiently.

Abstract: Methods based on resource circuits have become a research hotspot in the field of deadlock control recent years. Based on resource subnet and the trees of resource places, this paper proposes an effective method to compute all the resource circuits in a class of Petri nets called S3PR. When the proposed method is used in deadlock prevention policies, the computational efficiency can be significantly improved. An example is used to illustrate the application of the proposed method.

Abstract: This paper proposes a two-direction green wave control algorithm of traffic signal based on particle swarm optimization. The traffic flow model of queuing length and two-direction green wave control object function were built. The signal split and the phase offset were optimized by particle swarm optimization. The simulation result with traffic data collected from Liansheng Road in Dongguan City proved this method was effective and practical. Compared with graphical method and actuate signal control, the proposed algorithm could effectively reduce delaying time and shorten queuing length.

Abstract: In order to obtain dynamic behaviors of a spatial rigid-flexible coupling system of PMT(parallel machine tool) without the construction of mathematical model, a new method for dynamic behaviors simulation, which integrates CAD, CAE and visual technologies, was presented. The solid model of PMT was built in SolidWorks and transmitted to ADAMS, the modal neutral file of flexible body including driving limbs and spherical joints were generated in ANSYS, and introduced into ADAMS, then the rigid-flexible coupling model of PMT was build. Based on the rigid-flexible coupling model, the dynamic behaviors, which includes displacements error output response, dynamic stress of driving limbs and natural frequency, were realized. The simulation results show that the rigid-flexible coupling model established can indicate the dynamic behaviors of PMT. The flexibility of driving limbs and spherical joints are demonstrated to have significant impact on dynamics characteristics of PMT. This research can provide the important theoretical base of the optimization design of dynamic parameters for PMT.

Abstract: This paper presents the mechanical configuration of a quadruped robot with 4 rotary joints per leg firstly. All joints of the robot are activated by 16 identical hydraulic servo cylinders. Then it gives the forward and inverse kinematic equations of one leg with D-H transformation matrix. Furthermore, it also gives the jacobian matrix of the legs. The jacobian matrix establishes the relationships between the angle velocities of the 4 joints of the supporting leg and the moving velocity of the robot trunk. Lastly, a simple trot gait simulation is given based on MSC.ADAMS under the assumption that there are no slippages between the supporting feet and the ground.

Abstract: The paper presented a virtual design method of heavy-duty commercial vehicle axle development based on secondary development of 3D design and analysis software, which is directed towards the problems of duplication, low accuracy and high cost at present. Furthermore, the paper described the design process of Heavy-Duty Commercial Vehicle Drive Axle Rapid Development System Software(hereinafter called "the software"), which includes framework of software system, engineering database design, secondary development to Pro/Engineer, and secondary development to ANSYS. Moreover, the paper described the implementation process of parametric design, automatic assembly, interference check, and automatic finite element analysis by taking the driving axle shell design as the example. The software had already applied in a driving axle producer in china, and achieved the desired objectives.The method not only applys to parts parametric design development for driving axle, but also provides a reference to developing parametric design analysis system for other products.

Abstract: The problem considered in the paper is the structure design and modal analysis of Mecha in HD-NVD player. Regarding general DVD player, the influence on pickup from structure designs of spindle motor and base, assembly accuracy etc. have already been solved. But for HD-NVD player, as the speed of spindle motor working in the range from 3000 to 7000 r/m, so the these influence on pickup above correlative element have to be solved by complicated analysis. Through using ALGOR to design and analyze Mecha, obtained the structure dimension of base and modal characteristic, found its material property effecting greatly on the vibration of Mecha. With the increase of material rigidity in the base and motor stator, the system rigidity increases, then the vibration of system decreases. The result indicates that the Mecha designed and analyzed by ALGOR can meet the operating demand of HD-NVD player.

Abstract: Rescaled range (R/S) analysis has regained in popularity as a robust tool for the examination of long-term dependence. This paper modified the R/S method to determine the periodicity. We firstly apply the modified method to artificial time series for investigating the validity of the new method. Then the proposed technique is employed to research periodicity of the sunspot time series and the results indicate the robustness of the modified method.