Advanced Materials Research Vols. 118-120

Abstract: Robust design has been widely applied in quality improvement. For most products, quality is multidimensional. Little attention has been paid to multiple quality characteristics robust design (MQCRD). MQCRD mainly faces two problems: measurement model and multiple objectives optimization. In order to give an appropriate measurement criterion and generate better Pareto solutions, a MQCRD model by the Weighted Tchebycheff method based on the mean square error (MSE) criterion is proposed. Firstly the MSE estimations for each quality characteristic are obtained by response surface method (RSM) and a MQCRD model based on the MSE criteria is given. Then a MQCRD model by the Weighted Tchebycheff method is present, which minimizes the distance between objective functions and the idea point based on the weighted infinite norm. The proposed approach could find very efficient Pareto solutions. Illustrative example shows the model can generate more efficient and robust solutions than the weighted-sum approach. Furthermore it has better results than the generalized reduced gradient (GRG) and quadratic loss function approach.

Abstract: The theoretical and experimental studies of statistical evaluation method for flatness error are conducted thoroughly, and evaluation parameters and corresponding practicable data processing model are provided. Furthermore, a large number of experiments have been done and statistical analysis has been conducted. The results show that the distribution of extract elements of almost 90 percent of the measured planes is accordant with censored normal distribution, which proves that statistical flatness error obeys normal distribution. The characteristic that sample points are random variables is taken full advantage of in the statistic method, and the flatness error can be calculated without the influence of gross error and therefore the rate of waste parts can be reduced effectively.

Abstract: Software reliability has been regarded as one of the most important quality attributes for software intensive systems, especially in embedded system domain. Software reliability engineering is focused on engineering techniques for developing and maintaining software systems whose reliability can be quantitatively evaluated. As most of embedded systems complicated functionalities and controls are implemented by software which is embedded in hardware systems, it became more critical to assure high reliability for software itself. At this point, there is no visible boundary between Software reliability and software safety. Although software reliability has remained an active research subject over several years, challenges and open questions still exist. In particular, vital future goals include the development of new software reliability engineering paradigms that take software architectures, testing techniques, and software failure manifestation mechanisms into consideration. In this paper, we give a paradigm of embedded system, and do some analysis about it by using Generalized Stochastic Petri Net (GSPN).

Abstract: As one of the key parts of rotating machinery, rolling bearing is the primary fault source, therefore it is urgent to research failure mechanism and its evolution process. First, the number of laden rollers of rolling bearings in different states without radial clearance and preload is summed up, and then nonlinear analytical equations and an additional equation are proposed. To some extent it will be helpful for researching the fault evolution process of rolling element bearings combined with fatigue theories. Further they will conduce to analyze and predict the remaining life of ball bearings.

Abstract: In order to accurately obtain lateral stiffness of flexicoil circle spring with rubber pads, based on shear shape coefficient of solid and hollow thin-wall circle section, the shear shape coefficient of hollow circle section with different ratios between inner and outer diameter was obtained by difference method. By means of curve’s differential equations of elastic straight bar with uniform section, relations between forces and displacements as well as moments and rotation angles on end surfaces of spring and rubber pads was set up. According to the principle that force and moment under the connection surface between spring and rubber pad are the same and their signs are opposite, lateral stiffness of flexicoil circle spring with rubber pads was obtained. Calculation results show that in order to obtain accurate solution, correction factor of stiffness matrix must be considered when only lateral stiffness of spring is calculated, but the correction factor can not be considered when lateral stiffness of spring with rubber pads is calculated.

Abstract: Aimed at the challenges existing in current network performability research, this paper proposes an analysis architecture for network performability research, in which FMEA of the network, the availability model of the equipment, the topology analysis, the performance evaluation and the design of performability verification platform are integrated into together. This architecture assures accuracy of the performability analysis. According to the performance evaluation criterions, Capability-based performability, delay-based performability and PLR-based performability measures to the computer networks are suggested.

Abstract: Using the traditional vibration theory and fluid dynamics, the dynamic parameters satisfying the requirements of the 150t/h large-sized vibration fluidized bed were calculated, and the dynamic behavior of the bed was simulated with the ADAMS software. The parameters were optimized according to design requirements and a feasible model and valuable parameters were achieved.

Abstract: In this paper, under House of Quality(HOQ) Fuzzy Theory, taking product planning House of Quality(HOQ) as an example, systematically considers fuzzy auto-correlation matrix of engineering properties influence on engineering properties target value and development cost, by definition some concepts, such as engineering properties plan improvement level, practice improvement level, fuzzy planning cost coefficient and fuzzy actual cost coefficient, establish properties target value optimization model based on House of Quality(HOQ) Fuzzy Theory, and validate this method by a case study.

Abstract: In this paper, the flow field in the desulphurization tower is studied deeply based on two-fluid model, particle dynamics theory and FLUENT. A numerical simulation analysis of fluid within the desulphurization tower is done and the desulphurization tower is the major equipment in the system. The simulation design and calculations show that the two-fluid model is reasonable to analyze the flow field. The simulation results show that smoke can form good reaction environment within the desulphurization tower. It is meaningful for the further optimization of designing desulphurization tower structure in the circulating fluidized bed system.

Abstract: Transverse vibration analysis is presented for Euler-Bernoulli beams carrying concentrated masses and taking into account their rotatory inertia at both ends. The dimensionless eigenfunctions for the problems are first obtained using the differential equations of motion and considering translational and rotatory springs at both ends. A numerical technique, the Newton–Raphson algorithm, is then used to solve vibration eigenfunctions of the beams. Finally, the influences of different non-dimensional parameters on frequencies are discussed.