Advanced Materials Research Vols. 44-46

Abstract: According to the piezoelectric material damage theory and the fracture criterion based on damage theory, which has been established by Yang et al, reliability analysis of a damaged piezoelectric truss is carried out. The expression of safety margins of the piezoelectric beam has been proposed, with the mechanical damage extension force, electric damage extension force, Inertia Moment of cross-section and nodal loads as stochastic variables. Then the truss is dealt with randomly, and the corresponding reliability index is got according to the Taylor stochastic finite element. The result indicates that the reliability of the system is influenced greatly when the positive and negative electric fields have been applied on the structure, which provides the basis to control the reliability of structural system. Finally, through a calculation example, the quantification results of the reliability index are compared under the conditions of positive electric field, negative electric field or no electric field.

Abstract: As the reliability test data of complicated mechanical products is rare in quantity on the system-level and difficult to determine the accurate composition of the life distribution unit as well, the traditional reliability evaluation method based on evolutionary theory has been of little use. And the Statistical Learning Theory begins to be widely focused on as a novel small sample statistic method, which has been mostly applied to pattern recognition, fault detection, time series prediction and so on. This paper creates a new method for reliability evaluation derived from Statistical Learning Theory. By constructing Support Vector Machine with analog reasoning, and solving linear operator equation, the probability density of product can be evaluated directly and then the product reliability index can be obtained. Compared with the traditional way, this method can apparently increase the accuracy and generalization ability of reliability evaluation within limited samples. Finally, this paper presents the bridge of a certain heavy special vehicle as an example to testify the efficiency of this method, and uses the accelerated life test of the vehicle bridge to estimate its reliability.

Abstract: Manufacturing enterprises need to manage many inventory items. To effectively manage the inventory, a usual practice is to classify the inventory items into several groups and use different management strategies for the items in different groups. ABC classification has been widely used, and has evolved into various multi-criteria classification schemes. Recently, a few multi-criteria ABC classification approaches using variable weights appeared in the literature. This paper analyzes their properties and proposes an improved approach. A numerical example is included to illustrate the appropriateness of the proposed approach.

Abstract: The grey relation analysis is a kind of quantitative analysis method based on factors compared. The information axiom of axiomatic design provides a mean of evaluation by comparing the information content of several alternatives, based on which a new method for multi-attribute decision making is proposed. First, according to decision matrix of all decision making criteria, the ideal alternative composed of the best reference data series among all alternatives is constructed. Then the information content is used to evaluate the relation grade between an individual alternative and the ideal alternative. The fuzzy preferences are utilized to determine the weight of each criterion. The total information content of every alternative is calculated, and arrayed in order, so the optimal alternative can be selected. For requirements of evaluation, the calculation formula of information content is amended. Finally, an example is given to illustrate the effectiveness and feasibility of the proposed method.

Abstract: In this paper a simulation algorithm for concurrent product development process (CPDP) is presented based on Design Structure Matrix (DSM). An aggregate DSM is used to model the CPDP. To simulate the influence on the process of the time limit and the resource competition, the schedule and resource model are established. A method is also advanced to handle task delay. At last a case is used to validate the simulation algorithm and to show the influence on the process of task duration and resource.

Abstract: A product structure model for Rapid Product Design (RPD) is discussed. It is composed of Assembly Topology Tree (ATT) that describes the assembly relation between parts and the Part Topology Tree (PTT) that describe the geometry relation in a part, and it explains the constraint relations and the selection conditions between the components and parts. Product model class and its subclasses are built by Object-Oriented method to describe the structure and relation of a product and its components. At last an instance of the product structure model is introduced.

Abstract: One-of-a-kind production (OKP) is a new manufacturing paradigm to produce customized products based on requirements of individual customers while maintaining the quality and efficiency of mass production. In this research, a computer-aided optimal product design and process planning approach is developed to support OKP product design and manufacture to satisfy individual customer requirements with near to mass production efficiency. In this work, a hybrid AND-OR graph is developed to model the variations of design configurations/parameters and manufacturing processes/parameters in generic product family. Since different design configurations and parameters can be created from the same customer requirements, and each design can be further achieved through alternative manufacturing processes and parameters, co-evolutionary genetic programming and numerical optimization are employed to identify the optimal product design configuration/parameters and manufacturing process/parameters. A case study to identify the optimal design configuration/parameters and manufacturing process/parameters of custom window products in an industrial company is introduced to demonstrate the effectiveness of the developed method.

Abstract: Today, people have gradually realized that when we use new technology to create more comfortable life, it has paid a heavy environmental price. Therefore, we began to estimate our social development and design innovations with sustainable development thought. This paper seeks to find the source of the product life cycle, based on user needs as the research object, from the point of view as politics, economy, culture, lifestyle and many other aspects. Innovative product design characteristics of sustainable development are exlplored in depth, so that the products we designed, in a globalized competition environment, can live in harmony with the society and environment, meet people's needs, and at the same time, compete in the market with unique charm.

Abstract: A great idea always needs a certain shape to express itself. Meanwhile, a nice product design conveys its own connotation through a certain kind of material and manufacturing. As for all kinds of materials today, how to choose the most appropriate material through its own physical characteristics, which accords with our design idea and will not jeopardize our environment in the using process in its whole life span, is the emphasis of this paper.

Abstract: In this paper, the research and development of the distribution of air-holes in the groove of air-cushion belt conveyor were introduced. The expressions of air-cushion pressure were given and the graph of it was shown as well. The air flow model nearby groove-holes and air outflow model on cross section were given too. In the same time, the distributing mode of equidistant air-holes with unequal diameter was studied and analyzed. In order to make up the shortage of the study on air-hole distributing mode of equidistant air-holes with unequal diameter on the air-cushion belt conveyor, an instance of the air-cushion flow field was numerically simulated based on the CFD software ,Fluent software. Several groups of data of different air-hole distributions, (for example, the center distances of air-holes in the groove of air-cushion belt conveyor are the same as each other and their diameters are different), were selected to compare with each other , and then, the results were compared with existing theory. According to the different results of the numerical simulation on the distributing mode of equidistant air-holes with unequal diameter, the optimal parameters of air-hole distributing mode were obtained, and the effect of prevent offset that comes the balance groove-hole on air-cushion belt conveyor. Moreover, the verification to prove the agreement between the results of numerically simulated and basic theory was carried out by the comparison analyses. The theoretical feasibility of air-hole distributing mode of equidistant air-holes with unequal diameter was analyzed.