Materials Science Forum Vols. 532-533

Abstract: To improve efficiency and veracity of planning ACP, and to adequately utilize some knowledge or experience in ACP and the minds of assembly engineers, we apply CBR to ACP planning and present an approach to ACP planning based on CBR for aircraft. The approach mainly includes three aspects: (1) building case library of ACP and defining QC. (2) designing a algorithm searching ACC, including four key factors: SD of important coordination location; SD of assembly coordination approach; SD of assembly allowance requirement; SD of assembly benchmark; (3) retrieving and reusing ACC. Lastly, as shown by an example about a wing, our approach satisfies good efficiency and veracity of planning ACP and can make use of experiences of ACP.

Abstract: This research proposes a new integrated framework to support the inter-enterprise function integration, system structure and collaboration over the networked environment. In contrast to the existing system integration, the proposed framework enables the systematic amalgamation of large complex product development PMIS (Project Management Information System) and correlative sub modules in ERP (Enterprise Resource Planning). In addition, this framework is more suitable for building the large-scale manufacturing systems that are prone to dynamic random changes of their environment. It is shown on a practical case -- the implementation of AA Company’s PMIS in the environment of ERP system. The result indicates that the information integration framework on the large complex product development PMIS with ERP is operable and practical.

Abstract: In this paper, the shape defect is studied by the experiment of drawing parts before and after trimming for the rectangle cylinder shallow shell. The mechanism of shape defect and the effect of forming condition and trimming on shape defect are discussed. And the influence laws of forming conditions on shape defect are achieved. Such as binder force, curvature radius, sheet thickness, yield strength and residual stress after trimming.

Abstract: A orthogonal cutting of a kind of difficult-to-cut material is simulated using a finite element model, which is considered dynamic effects, thermo-mechanical coupling, tool-chip friction, chip separation criteria. Marc program is the computational tool in the model. Johnson-Cook’s model is employed as the constitutive law for the workpiece material. The frictional behavior of the sticking and sliding tool-chip interface is described by Coulomb’s law. Remeshing technique and mesh adaptive technique are also used. The research mainly specializes plane strain and continuous flow chip. The emphasis is placed on the parametric modeling of tool and workpiece. Then the cutting force and temperature in cutting process from initial state to steady state is conducted by simulation. Finally the Experimental value is compared with the simulated data.

Abstract: The technique of collaborative design and manufacture is not only very important, but also urgent necessary for space antenna. Building on unicode, XML provides the standard format describing data in various types, so it has the virtue of integrating heterogeneous databases. In this paper, the elementary research has been done on XML-based integrating technique for heterogeneous databases of space antenna. Firstly, the overall flow for collaborative design and manufacture of space antenna shows that five databases should be integrated. Secondly, a XML-based integration system frame is conceived for space antenna databases. Thirdly, an effective XML-based transformation mechanism is proposed for the data integration process between relational database and document-based database. Finally, the implement of XML-based database integration is demonstrated in a space antenna design.

Abstract: In order to define the intermediate workpiece information for the digital manufacturing of aircraft sheet metal parts, the Manufacturing-Oriented Multi-State Model for Sheet Metal Part (MOSS) is further studied. The model structure is constructed by the hierarchy of State, Feature, Element and Data (SFED). The hierarchy represents its content and relationship among its components in detail. The model application scheme shows that state information can be integrated with the systems of process planning and tool design, and the model provides a foundation for digital and intelligent manufacturing of aircraft sheet metal parts.

Abstract: In this paper, algorithms are presented for predicting peen forming parameters of integral aircraft wing panels with complex airfoil shapes. The peen forming deformation is divided into stretching deformation and bending deformation. The stretching deformation is assumed to result from the tensile strain within the plane panel, and the bending deformation corresponds to the difference of maximum and minimum curvature of the airfoil surface. The distribution of the forming tensile strain within the panel is obtained by optimal mapping of the airfoil surface in the sense that the stretching deformation energy from the plane panel to its spatial shape is minimized. In order to fit the nonlinear relation between the peening parameters and the deforming parameters, a back-propagation (BP) artificial neural network (ANN) is modeled with input parameters of thickness, curvature, tensile strain, etc, to predict the peening parameters of coverage, air pressure and intensity. Experimental peen forming data are given to train the BP ANN. It’s verified that the predicting methods are effective.

Abstract: We explore the price and welfare effect of price discrimination in a differentiated-goods oligopoly market with network effect and the effect of network effect on the equilibrium price, profit and output. We show that competitive price discrimination and network effect may intensify competition and the price discrimination increases the social welfare under oligopoly market with network effect. If firms differ in which markets they target for aggressive pricing strategy and competitive firm’s reaction is strong, prices in all markets may fall. So both firms agree on the strategies of setting the uniform pricing.

Abstract: Focusing on the difficult-to-cut characteristic of titanium alloy, this paper selects several cemented carbide tool materials in the tests of machining the titanium alloy workpieces. Different sets of geometrical parameters of the drilling bits are grouped, chosen and optimized, and then deep-hole drilling tests are carried out. The suitable cutter materials and the optimum geometrical parameters of the cutter for drilling deep holes in titanium alloy have been determined through the analysis of tested results.

Abstract: In order to discover the typical process route (TPR) in the Computer Aided Process Planning (CAPP) database, Hierarchical Clustering algorithm is adopted. A mathematics model based on the data matrix was built to describe the process route (PR). On the base of the operation code, the distance between operations, between the PRs, between clusters were measured to evaluate the PR similarity. Then, the PR clusters were eventually merged by the hierarchical clustering algorithm. Three methods are listed to confirm the clustering granularity that determines the clustering result. This TPR discovery method is successfully applied to discover the axle sleeves’ TPR.