Wanshan Wang

Fabrication of Repairing Skull Bone Defects Based on the Rapid Prototyping

The Rapid Prototyping (RP) manufacture technology, computer tomography (CT) image processing, and mechanical analyses were adopted to repair a skull defect injury. After the patient was inspected by spiral CT the data was exported to Digital Imaging and Communications in Medicine (DICOM) format. The data was processed with Mimics software to eliminate noise and gray-level registration. The processing filtered out the parenchyma data and preserved the bone data. The STL files were analyzed and processed by the Magics and put into the RP equipment. The RP equipment is one type of Stereo Lithography Apparatus (SLA) with laser light spot diameter that is <0. 2mm The 3D models were analyzed to comply with the patients’ requirements. The stereo lithography model emulated the mechanical properties and shape with the patients bone. The titanium-alloy plate matched the anatomy well. The 3D reconstructed freeform model was accurate to within 0.2 mm.

Air combat effectiveness assessment of military aircraft using a fuzzy AHP and TOPSIS methodology

Air combat is the basic operational means of air force. This paper models the air combat effectiveness assessment problem as a multi-criteria decision making (MCDM) problem and proposes a two-step evaluation model, combining the technique of fuzzy AHP (fuzzy analytic hierarchy process) and TOPSIS (technique for order performance by similarity to idea solution). This study applies the fuzzy AHP method to determine the relative weights of multiple evaluation criteria and to synthesize the ratings of candidate aircraft. Aggregated the evaluatorspsila attitude toward preference; then TOPSIS is employed to obtain a crisp overall performance value for each alternative to make a final decision. To illustrate how the approach is used for the air combat effectiveness assessment problem, an empirical study of a real case involving seven evaluation criteria, six initial military aircraft assessed by 15 experts is conducted. The case study demonstrates the effectiveness and feasibility of the proposed evaluation procedure.

Integration of the CAD/PDM/ERP System Based on Collaborative Design

The increasing requirement and product complexity need a new design method for the global market. The collaborative design is an important style for the requirement. The CAD system for design is connected with the Product data management (PDM) and enterprise resource planning (ERP) system for management. PDM can support the management of engineering data and the product development. A methodology for the PDM/ERP/CAD integration is proposed. Firstly, the interest of integration of PDM/ERP/CAD is introduced. Then the UML-based methodology is applied for the product data integration model. The PDM structure model diagram and the class model diagram are introduced. Workflow method for the method is introduced. By workflow method, the data publican is realized by the trigger. The data among systems can be visited and exchanged by the methodology. As a result, the design and management models are modified, simultaneously and maintained consistently. The methodology is applied for a system by means of an example, which achieves a good result.

Applications of virtual reality in turn-milling centre

Virtual reality (VR) is a high-end human computer interface that strives to immerse the designers and users completely in a virtual interactive environment for a simulation of real world. In order to meet the requirements of market competition, VR technologies can not only reduce effectively the time and cost, but also optimize complex products in the design process. PVAS (Products Virtual Analysis System) is developed in the paper. The system can realize three main functions. Firstly, products are displayed for the designers and users with stereo glasses. Secondly, products performance is analyzed and optimized in virtual environment. Thirdly, virtual machining and virtual assembly are realized. At present, the translation of data form CAD to virtual reality is often unidirectional and unsatisfactory. Since the limitation is the different data formats used for CAD and VR, two different approaches are proposed in the paper. Finally, the paper takes virtual reality applications in turn-milling centre an example. Using three-dimensional computer graphics, interactive devices, and stereo glasses, turn-milling centre machining simulation can be realized in a virtual world as if it were in the real world. Therefore the method that complex products based on VR are analyzed is significant and has application value.

Research on prognostic health management (PHM) model for fighter planes based on flight data

Flight data records many important state parameters, which will be useful to process monitoring and fault diagnosis of fighter planes. Aiming at the problems of backward data processing means, poor analytical facilities and limited range of application in the maintenance of aircraft, this paper proposes a PHM model for fighter planes based on flight data. Architecture of the PHM system contains onboard data acquisition subsystem and ground-based data processing subsystem. Based on the onboard data acquisition subsystem, function model of ground-based data processing subsystem was analyzed and the ground-based data processing subsystem was designed in detail from software to hardware. Some key technologies such as data pretreatment, tendency analysis, fault forecasting, state monitoring and decision consulting are depicted and specific methods of realization are given concretely.

Knowledge management in collaborative design

To enhance the product development ability of enterprise, collaborative design is applied to new product development. Knowledge management among designers is an important problem for collaborative design. A computerized knowledge management system for collaborative product development is present to solve the problem. A framework of knowledge management based on ontology is present. The collaborative knowledge is introduced to assist to acknowledge the process of collaborative design. Knowledge based on ontology is constructed, which is the critical part of system. It can solve the problem of the knowledge sharing and knowledge application. At last, the framework of knowledge management system is constructed, which integrate the knowledge management with collaborative design process. The framework can realize the knowledge capture and reuse to enhance the efficiency of design.

System of CRM Performance Evaluation Based on Fuzzy Comprehensive Algorithm

With the level of informatization is improving CRM has been used by enterprises universally and it makes the working efficiency has been improved. In order to improve the CRM performance needs to do a scientific and comprehensive evaluation. The evaluation on CRM performance is a complex systemic project. A CRM performance evaluation method based on fuzzy comprehensive evaluation is presented. Comprehensive evaluation method of CRM performance based on fuzzy comprehensive algorithm is studied, the architecture of the system is built and the function of the system is analyzed. Based on those works a prototype system of CRM performance evaluation is developed. Results of the system run prove the correctness of the theoretical and the feasibility of the technology.

Research on the Workflow System of Collaborative Process Planning

It is extremely important for effective control and management of process planning, but there are many shortcomings with traditional process planning system in these aspects. To solve these problems and meet the process informationization requirements in manufacturing enterprises, application of workflow technology in collaborative process planning system was discussed. Semantic decriptions of workflow and workflow intergrating with process planning were defined to further describe the workflow of process planning. The function structure and architecture of the system were designed based on the analysis of part process features of process planning. A workflow system of collaborative process planning was developed and workflow engine as the heart of the whole system was designed based on JBOSS JBPM, which greatly improves the control capability of the process and the efficiency of process planning.

Research on Virtual NC Technique in Turning and Milling Process

A virtual machining system based on virtual manufacturing technique and NC machining technique for turn-milling center is developed in this paper, which can realize all processes from the establishment of NC procedure to machining simulation. On the platform of visual C++, the virtual machining environment is built by OpenGL technique, and the structure of machining simulation system and its function are proposed. According to turn-milling center characteristic, the mathematical models about turning and milling are respectively built in virtual NC machining process. The geometric simulation and physical simulation are realized on the basis of the models by C++ language. The research demonstrates that the simulations are handled to complete the virtual machining of the product by checking machining ability, rationality of design, prediction manufacture circle, and promptly modifying design. The method offers the theoretical foundation and reference value of practical application for structure design of turn-milling centre.

Development and Research of Simulation System of Vitrified Bond CBN Grinding Wheel Based on Virtual Reality Technology

The traditional study on grinding is testing the same material in conditions of different grinding parameters on a dedicated grinder, or testing different materials separately, which will not only waste a lot of human and material resources, but also extend the research and development cycle of wheel products, increase wheel product development costs, reduce the efficiency of study. If virtual reality and simulation technology are used to replace or reduce the actual experimental work, the grinding wheel manufacturing costs can be decreased and the competitiveness of R & D departments are increased, especially the diamond, CBN and others higher-cost super hard abrasives. This paper briefly introduce to some of the basic theory about the virtual reality simulation technology, then develop the grinding process modeling and simulation system of vitrified bond CBN grinding wheel by the MFC with OpenGL graphics library in the Microsoft Visual C + + 6.0 platform. After system simulation testing, the wear state of vitrified bond CBN grinding wheel on different conditions and different periods in the grinding process are predicted. Keywords-virtual reality; simulation; CBN grinding wheel; grinding