Advanced Materials Research Vols. 44-46

Abstract: The effect of formulation (filler’s kind and amount, liquid’s kind and concentration required for granulation) and spheronization time on characterization of alumina based pellets parameters (pellets size distribution, roundness and aspect ratio) were investigated. Two schemes were successfully proofed by extrusion/spheronization. The mean volume particle diameter was found to have a profound effect on the formulation and processing parameters. Alumina powder with large mean volume particle diameter showed different mechanism of action with coupling agent. With the surface modification, the water required for granulation had decreased. The existing formal and kinematic velocity of the water had a direct effect on the processing parameter of the extrusion and spheronization. Spheronization time from 2 to 10 min had a pronounced effect on roundness and aspect ratio. No changes in roundness and aspect ratio were observed from 10 to 20 min of spheronization time.

Abstract: Based on the CBR technique and the characteristics of developing corrosion inspection tasks and intervals of aircraft structural items, a new method which can determine the initial scheduled preventive maintenance tasks and intervals of aircraft structural items is given, and is implemented by the tools of object -oriented program design method and visual C++ language. Finally, an example of wing assembly of some model of aircraft in china is given in order to validate the feasibility of this system. The results indicate that the CBR-MTI system can establish the maintenance tasks and intervals quickly, and its consequences are more consistent with the actual situation because all maintenance tasks and intervals in the case-base have been validated by the actual operation of other aircraft.

Abstract: Interoperability can be described as the interpretability of data types and related information by different computer systems. Standards for data format and communication protocols have been developed and adopted by different industries. So far, interoperability has only been investigated at the data level. This paper addresses a research approach proposing a system design and a set of generic methods so that to embed engineering knowledge and to achieve interoperability at the feature level in an open collaborative engineering environment. Ideally, the proposed new approach would allow knowledge rules to be embedded into the constraints of features supported by the complex associations of a multi-application engineering repository. Potentially, the system proposed offers user-defined feature types that support flexibility in feature-based information definition, sharing and mapping.

Abstract: Designers need to reuse relevant knowledge types to make important decisions. These decisions are based not only on experience, but also on key knowledge global partners. A methodology to support information-knowledge management for global collaboration using DFX, PDM and Expert System tools is proposed. This new approach shows a manner to provide information from each stage of the product lifecycle to the designers through a PDM system. In addition, it includes a manner to store and share the knowledge created during the DFX process using an Expert System. This methodology provides integration to product realization technologies while supporting design stage in a collaborative environment when a large amount of information and knowledge to get a decision is required. The new approach implemented provides important benefits such as launching time and cost reduction, increased efficiency of designers and product innovation.

Abstract: A new up-and-down method is developed and a new estimate formula for the variance of sensitivity variables is proposed. This formula fully considers the effect of test conditions on the estimating accuracy, resulting in higher order of precision. In order to give an objective demonstration, the Monte Carlo comparative results between the present method and the Bruceton method is given, which shows that the estimating values by the present method are much more accurate than those by Bruceton method in all conditions. Even with small samples, the present method still could obtain a good estimate value. Thus the proposed method not only solves the problem with traditional methods but also reduced the number of experiment, resulting in great saving. Finally, an application for safety fatigue limits is given.

Abstract: A typical driving cycle reflecting the real-world driving conditions of city bus is developed to show average speed, running time, acceleration and deceleration time, and passengers flow on the city bus with the case study in Dalian. A practical method for the improvement of the fuel economy with the application of the driving cycle for city bus is discussed based on the matching of drive train. The results show the practical value of the methodology on the improvement of the city bus fuel economy.

Abstract: In recent years, for the sake of energy saving and environment protection, lightweight body structure becomes the trend of vehicle development. Based on this objective, it is significant to make a research on optimization for the body structure. When structure optimization for the single work condition is carried out, the common mechanism optimization design method can provide the optimum result for certain condition according to the corresponding restriction and objective functions, whereas, the same variable has different variation trends in different conditions. In order to satisfy the requirements of the actual condition with multi-load cases optimization, synthesis analysis should be carried out by introducing weights for corresponding variables. First of all, the optimization section sizes of frame members of one semi-integral fuel cell bus body are analyzed respectively under four different load cases by applying common mechanism optimization design method. Furthermore, orthogonal design of experiment method is adopted to analyze the effect factor of the four optimization results in the synthesis optimization analysis and ascertain the integral optimum scheme. By analyzing and checking the bus body gained from the optimum synthesis scheme, it is confirmed that the synthesis optimization method for structure by adopting both common mechanism optimization design method and orthogonal design of experiment method can be used to carry out the optimization analysis under multi-load cases for bus body frame and the lightweight of bus framework, on the premise of ensuring the bus body performance index such as strength, stiffness and mode.

Abstract: With the mechanics model, the analytic formula of the deformation for the trapezium throttle slice was established. By the vehicle parameters and valve opening velocity, the formula of valve opening pressure was built. Based on this, through the relation of pressure with deformation and flux at valve opening, the design formula of throttle slice thickness and throttle-hole area were established, the influencing factors to the design parameters were analyzed. A practical example of design of hydro-pneumatic spring was given, and the performance test was conducted. The analysis and test results show that the design method is effective and the formulas for throttle slice thickness and throttle-hole area are accurate enough, and have important meaning for the hydro-pneumatic spring design.

Abstract: Analytic modeling and analog computer simulation techniques are presented to determine the power train transient responses excited by clutch-actuated gear shifts. A method to describe the dynamics of a transmission arrangement having several clutches and interconnected planetary gear sets is considered in detail. Simulation model testing is directed toward optimizing system design parameters and evaluating power train component capability and vehicle shift-feel. Data reduction techniques applied to model responses of torque and speed will yield appropriate spectrums representative of simulated work cycle.

Abstract: Axiomatic design and design structure matrix (DSM) are two popular design methods at the moment, while most related researches only apply the basic ideas of axiomatic design or DSM to some cases. This paper first analyses the disadvantages of both axiomatic design and DSM. After deep investigations, the paper then puts forward that there are strong complementarities between axiomatic design and DSM. Based on the complementarities between axiomatic design and DSM, it is proposed that axiomatic design’s design matrix (DM) can be transformed into corresponding DSM for structural evaluation. In this way, axiomatic design and DSM can benefit from each other. The logic of integration between axiomatic design and DSM is interpreted in this paper. A computer aided conceptual design system has been developed to enable the integration of axiomatic design and DSM.