Chong Su

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.

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.

AHP Methodology for Partner Selection in Collaborative Design

Collaborative design is a new design style for mechanical manufacture. It can help designers of different places complete the same design project at the same time. It is an important problem to select a suitable partner for the collaborative design project from the partners. A fuzzy analytic hierarchy process (AHP) methodology is presented for the partner selection, which provide a multi-criteria decision making approach for partner evaluation and selection decision. Firstly, the concept of fuzzy analytic hierarchy process (AHP) is introduced, which assist to acknowledge the concept. Secondly, the methodology for criteria weights is established to search for the suitable partner by fuzzy AHP method. The partner selection system is established by means of fuzzy AHP method. XML is applied for the evaluation model to explain the relationship of system. At last, a prototype is presented to demonstrate the methodology.

Partner Selection System for Collaborative Design

With the development of the global market, the growth internet technology is changing design style. Collaborative design is a new design style for designers of different places to complete the same design project. However, how to select a suitable partner for the collaborative design project is an important problem. A fuzzy Analytic Hierarchy Process (AHP) methodology is presented for the partner selection, which provide a multi-criteria decision making approach for partner evaluation and selection decision. Firstly, the concept of fuzzy Analytic Hierarchy Process (AHP) is introduced and the framework of system is constructed. Secondly, the criteria weights are calculated by the fuzzy AHP to search for the suitable partner. Then the partner is found by AHP. The system for partner selection is established by means of fuzzy AHP method. XML is applied for the evaluation model to explain the relationship of system.At last, a prototype is presented to demonstrate the methodology.

Numerical simulation and analysis for metal cutting processes based on FEM and SPH

By using the coupling method of FEM and SPH, constitutive behavior of material in the metal cutting process was simulated and cutting mechanisms were analyzed. The simulation results show that the cutting process is a plastic deformation process in which cutting layer material produces shearing slip due to the extrusion of cutting tool; the extrusion and friction from cutting edge result in cold plastic deformation of material in formed surface layer, and form residual stress; the cutting force increases rapidly and then decreases, eventually varies in a certain range; the maximal effective stress varies at a certain distance to the cutting edge in stable cutting stage.

Finite Element Simulation of Chip Formation with Single Grain

Three-dimensional cutting process of single grain in the shape of polygonal pyramid was simulated by coupled Euler-Lagrange method. The method makes the workpiece material free from its meshes. The material allowance can be removed without mesh separation criterion. The simulation results show that workpiece material flows to the side and front owing to the pressing of cutting plane. Chip flows out along the front of the grain upward. The deformation of workpiece material contacted with grain edge is very severe. Therefore there is large machining stress concentration at the contact zone of grain edge. It results in biggish residual stress and cutting temperature at the side and bottom of the groove. The contact stress at edge angle of abrasive grain is biggest. Therefore grain wear is severe in the position

Modeling of Virtual Grinding Wheel and its Grinding Simulation

Based on virtual reality technology, a friendly human-computer interaction interface and virtual machining environment were developed by Visual C++ and OpenGL. Considering the inhomogeneity of grain size and randomicity of grain distribution, virtual grinding wheel was modeled by taking ortho-hexahedron as basic shape of abrasive grains and randomly distributes them on the wheel base. Mathematic model of interference between abrasive grain and workpiece was established. By using the virtual grinding wheel modeled, surface grinding processes with different machining parameters were simulated. The simulation results show that the system could make operators have a further understanding to chip formation, and the machining results could reflect realistic surface topography of workpiece. Complex grinding process can be realistically simulated. It provides visualization models for the research of grinding mechanism and production forecast.

Research and Development of Simulation System for Virtual Grinding

Based on virtual reality technology, the paper does some researches and developments for virtual grinding system. A friendly human-computer interaction interface and virtual machining environment are programmed with Visual C++ and OpenGL, and their characters of interaction and immersion are embodied completely. Physical model of virtual grinding wheel and mathematical model of contact between abrasive grain and workpiece are built. Take surface grinding as an example, the simulation system is tested. The results show that the simulation system could make operators have a further understanding to chip formation, and the simulation results could reflect realistic surface topography of workpiece. So the simulation system could be used to forecast surface roughness in actual abrasive machining.

Finite Element Analysis of Two-Dimensional Metal Cutting Process

Based on LS-DYNA software, metal cutting processes are dynamically simulated by using 2D r-adaptive method. The mechanisms of plastic deformation and chip formation in metal cutting are analyzed. The influences of tool rake angle and friction factor on cutting deformation are analyzed and deformation extent is measured by plastic deformation energy. According to the distribution of stress and strain gotten from the cutting simulation, the generation of compression stress and residual tension stress of the workpiece is analyzed. The distribution of cutting temperature field is also analyzed. The research method can effectively apply to the study of metal cutting theory. It is helpful for the selection of bit tool and technological design of machining.

Fuzzy Case-Based Reasoning for Conflict Resolution in Collaborative Design

The collaborative design is an important style for modern design. But the conflict appears in the process of design which may interface the design. Case-based reasoning (CBR) is a good method for conflict resolution, which has been applied in the artificial intelligence field successfully. However, due to the uncertainties in knowledge representation, attribute description, and similarity measures of CBR, it is very difficult to find the similar cases from case database. To solve the problem of conflict resolution in collaborative design, a fuzzy case-based reasoning (CBR) is proposed. The process of fuzzy case-based reasoning (CBR) is introduced. Based on the feature attributes and their relative weights determined by a fuzzy technique, a fuzzy CBR retrieving mechanism is developed to retrieve conflict resolution cases that tend to enhance the functions of the database. The theory and methods of fuzzy CBR is applied to define the cases. By indexing, calculating the weight and defuzzication of the cases, the case similarity can be obtained. Then the case consistency is measured to keep the result right. Finally, the method is demonstrated availably for conflict resolution by means of a case study.