Applied Mechanics and Materials Vols. 26-28

Abstract: Based on the chaos theory, the adding-weight one-rank local-region method was applied to predict the time series of the rolling bearing friction torque. The experimental investigation on the rolling bearing for space applications shows that the method is able to predict effectively the rolling bearing friction torque, only with very small predicted error.

Abstract: The dynamic modeling of a six-leg-wheel hybrid mobile robot was built using ADAMS software in this paper. Using the ADAMS model, the kinematic simulation, including the displacement, velocity and acceleration of each part of the robot, can be carried out and the dynamic simulation, including driving torque of joints, contact force and torque between the wheels with ground and the ability of obstacle negotiation, can also be achieved. The simulation examples were presented. The simulation analyses provide the theory basis for the design of the robot control system based on dynamics.

Abstract: The stiffness and damping of mechanical joint are modeled by the zero thickness joint interfaces theory. The method is applied to analyze the dynamic characteristic of the gantry frame in a five axis turning-milling compound CNC machine tool. The model test is carried out in the gantry frame, and the maximum error of the first sixth mode is 5.63%. The experimental and analysis result show the zeros thickness joint element can provide an effective method to model the machine joint and predict the dynamic characteristic of the assembled structure.

Abstract: The problems of quality management (QM) in traditional consecutive development were analyzed, and it was pointed out that there were essential differences between QM in concurrent development mode and that in consecutive development mode. One was modification or change in work process, and the other was cooperation within Integrated Product Team (IPT) members aiming at product quality improvement. According to the characteristics of concurrent development, QM mode and process models appropriate to Concurrent Engineering (CE) were established. The models were able to demonstrate QM responsibility distribution, specific QM work patterns and flow, as well as quality information processing and transfer among the development phases. The models provided guidance and reference about how to enhance quality management of product development process.

Abstract: This article established a new combining hierarchy genetic algorithm and multivariate linear regression model of WNN (wavelet neural network) for identify the feature of rotary machine. The effection on the question of nonlinear approximation is verified through the simulation and optimization. The test datas of a tandem mill are inputted into the model. After trained, the model has automatic ability of obtained the inspect information and the ability of adapt the changing of worked condition. The self-adaptive study and diagnosis of torsional oscillation state on different work condition are realized. The results verify the combining hierarchy genetic algorithm and multivariate linear regression model has the reliability.

Abstract: Transaction cost is one of these costs, but mostly mentioned with trade barriers. The trade barrier, also called tariff barracks or non- tariff barracks, focus on the problems that affect transactions in international trade. Transaction cost in economics can be defined as a cost incurred in making an economic exchange. There are a number of kinds of transaction cost have been researched by economists, “search and information costs” (such as those incurred in determining that the required good is available on the market, who has the lowest price.), “Bargaining costs” (the costs required to come to an acceptable agreement with the other party to the transaction, drawing up an appropriate contract and so on.), “Policing and enforcement costs” (the costs of making sure the other party sticks to the terms of the contract, and taking appropriate action if this turns out not to be the case.). Along with the fast development of e-commerce, a new kind of trade barriers, which is called e-commerce barrier, based on information technology appears quietly, in recent years. Though the emergence of this barracks does not been focused by world, it has profoundly affected international trade already.

Abstract: The vibration signal of diesel engine is typically non-stationary and time-varying signal, with complicated transient components. With adaptive concentration method controlled by an additional parameter m, an adaptive generalized S transform (AGST) is developed in this paper. The simulation shows that the AGST method has a better time-frequency resolution than S transform. The AGST method is then applied to analyze the vibration signal of the cylinder head cover of a four-cylinder diesel engine. The result indicates that the time-frequency representation of the vibration signal obtained by AGST has a good resolution, and the vibration components, such as combustion shock and valve-slap, can be exactly identified. The research is of great significance for the structural optimization and vibration control for the diesel engine.

Abstract: Photoelectrochemical (PEC) degradation of Procion Red MX-5B was investigated in aqueous NaCl solutions. PEC degradation efficiencies showed strong dependence on the concentrations of aqueous NaCl solutions and applied potentials. 95% decolorization of the dye could be achieved in 10 minutes at applied potential of 8 V in 0.3 M NaCl solution, while the efficiency was only 35% by photocatalytic oxidation. Electrodegradation can be as powerful as PEC degradation upon dye decolorization when the potential exceeds 5 volts. However, it can not mineralize dye degradation intermediates by itself alone. PEC degradation performed very high TOC removal capacity and nearly 80% of total organic carbon was removed in the first hour of reaction, compared with 50% removal in PCO process during the same period.

Abstract: The theoretical value of bolt pre-tightening torque coefficient is typically 0.2 on load boundary condition simulations.A set of measuring setup has been designed in present study.Through direct measurement and electric measurement,a torque coefficient of 0.15 has been measured.The effects of pre-tightening torque coefficient on bolt stress field are studied numerically.Results show that the coefficient has significant effect on bolt stress fields and relatively conservative results will be achieved if a theoretical value of 0.2 is chosen.Studies on stresses around hole-edge and comparisons with test values show that simulated results of and agree well with test data and the relative errors are no more than 15%.

Abstract: The puzzle over the recognition of the quality of the Chaotic Dynamics based on single variable time series brings forward the new method of phase space reconstruction—identify the embedding dimension with the FNN after delay time is fixed through the method of autocorrelation function. By means of the numerical verification of a few typical examples of chaotic dynamic system, the result shows that this method can be able to efficiently reconstruct the phase space of the original system out of the time series and relatively completely reduce the dynamic characteristics of the original system and thus the validity of the method is testified on chaotic signal recognition.