• International Journal of CAD/CAM
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• v.9 no.1
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• pp.17-24
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• 2010

For several years, researchers have focused on improving the integration of the CAD, CAM and Analysis through a better communication between the various analysis tools. This tendency to integrate the CAD/Analysis and automation of the corresponding processes requires data sharing between the various tasks using an integrated product model. We are interested in this research orientation to CAD/CAM/Analysis integration by rebuilding the CAD model (BREP), starting from the Analysis results (deformed mesh). Because this problem is complex, it requires to be split into several complementary parts. This paper presents an original interoperability process between the CAD and CAE. This approach is based on a new technique of rebuilding the CAD surface model (Nurbs, Bezier, etc.) starting from triangulation (meshed surface) as a main step of the BREP solid model. In our work, the advantages of this approach are identified using a centrifugal pump example.

• Proceedings of the KSME Conference
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• 2001.11b
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• pp.523-528
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• 2001

There are many difficult problems in analyzing the flow characteristics in a high voltage circuit breaker such as shock wave and complex geometries, which may be either static or in relative motion. Although a variety of mesh generation techniques are now available, the generation of meshes around complicated, multicomponent geometries like a gas circuit breaker is still a tedious and difficult task for the computational fluid dynamics. This paper presents the computational method for analyzing the compressible flow fields in a high voltage gas circuit breaker using the Cartesian cut-cell method based on the CFD-CAD integration, which can achieve the accurate representation of the geometry designed by a CAD tools. The technique is frequently satisfied, and it will be almost universally so in the future, as the CFD-CAD traffic increases.

• International Journal of Automotive Technology
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• v.3 no.2
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• pp.47-52
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• 2002

The integration of CAD/CAM/CAE in product development is the key to realize concurrent engineering. Generally, different systems are employed in product development departments. These different systems create a lot of trout)toes such as difficulty in communication, misunderstanding and so on. A new approach to integrate CAD/CAM/CAE in one system based on CATIA thor the end-to-end process in cylinder head development is presented. Hulti Model Technology (MMT) is used to create consistent and associated CAD models for the end-to-end process in cylinder head development. The concept and method to create and organize multi models are discussed. A typical four-layer structure of HHT for mechanical products is defined. The multi level structure of the cylinder head models based on MMT is provided. The CAD models of cylinder head created based on MMT can be used as the consistent model. All models in the downstream of cylinder head development such as structure analysis, CFD, sand core design , casting simulation and so oil are associated with the CAD models. Practice shows the approach in this paper enables the development process to be carried concurrently and can obviously shorten time to the market, reduce product cost and improve product quality.

• Journal of the Korea Institute of Military Science and Technology
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• v.2 no.2
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• pp.209-217
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• 1999

In this paper, an integrated S/W system from CAD to optimal design has been suggested and an application to a precision machine tool structure shown. The integrated system is so designed to reduce manual interfacing effort. An object-oriented programming language is used for combining 3-D CAD program, FEM and optimal design tools. In this system parametric modelling technique is applied and users can get the optimum design iteratively without much user intervention. The CAD model is automatically updated when the design parameters are transferred back to the CAD program. Not only design time can be dramatically reduced but unnecessary operation errors avoided by the integration.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.612-617
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• 2008

In this present work, trimmed surface analysis for the 2D elasticity problem is presented. The main benefit of the proposed method is that no additional modeling for analysis of a trimmed surface is necessary. As the first attempt to deal with a trimmed surface in spline FEM, the information of the trimming curve and trimmed surface exported from CAD system is directly utilized for analysis. For this, trimmed elements are searched through employing projection scheme. For the integration of the trimmed elements, NURBSenhanced integration scheme which is used in NEFEM is adopted. The quadtree refinement of integration cell is performed for the complicated trimmed cases. The information of trimming curve is used for obtaining integration points as well as constructing stiffness matrix. The robustness and effectiveness of the proposed method are investigated by presenting various numerical examples.

• Proceedings of the KIEE Conference
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• 2001.10a
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• pp.30-32
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• 2001

There are many difficult problems in analyzing the flow characteristics in a high voltage circuit breaker such as shock wave and complex geometries, which may be either static or in relative motion. Although a variety of mesh generation techniques are now available, the generation of meshes around complicated, multi-component geometries like a gas circuit breaker is still a tedious and difficult task for the computational fluid dynamics. This paper presents the CFD program for analyzing the compressible flow fields in a high voltage gas circuit breaker using the Cartesian cut-cell method based on the CFD-CAD integration, which can achieve the accurate representation of the geometry designed by a CAD tools. This technique is frequently satisfied, and it will be almost universally so in the future, as the CFD-CAD traffic increase.

• Proceedings of the KSME Conference
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• 2001.06a
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• pp.926-931
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• 2001

In this paper a CAD-based optimal design system is introduced and applied to optimal design of machine tool structures. The system is designed to reduce manual interfacing effort. All the design activities such as selecting design variables, making FE meshes and FE analysis are integrated on a parametric CAD program. A user can easily select design variables by clicking a CAD model. To enhance the robustness and versatility, this system uses the finite difference method for the design sensitivity analysis. By taking a practical example of the design of the column of a horizontal machining center, it is shown that the software system is efficiently usable in industry establishing the goal of minimizing user intervention between various analysis and optimization activities.

• Korean Journal of Computational Design and Engineering
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• v.12 no.2
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• pp.137-145
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• 2007

This paper concerns about residential environment analysis program implementation for design and analysis on public housing complexes such that view and daylight analysis processes are automated and integrated into existing design routine to achieve better design efficiency. Considering the architectural design trends this paper chooses ArchiCAD as a platform for a CAD system, which contains the concepts such as integrated object-oriented CAD, virtual building and BIM. Residential environment analysis system consists of three components. The first component is the 3D modeling part defining 3D form information for external geographic contour models, site models and interior/exterior of apartment buildings. The second is the parametric library part handling the design parameters for view and daylight analysis. The last is the user interface for the input/output and integration of data for the environment analysis. Daylight analysis shows rendered images as well as results of daylight reports and grades per time and performs the calculations for floor shadow. It separates the site-only analysis from the analysis of site and exterior environmental parameters. View analysis considers horizontal and vertical view angles to produce view image from each unit and uses the bitmap analysis method to determine opening ratio, scenery ratio and void ratio. We could expect better performance and precision from this residential environment analysis system than the existing 2D drawing based view and daylight analysis methods and overcome the existing one-way flow of design information from 3D form to analysis reports so that site design modifications are automatically reflected on analysis results. Each part is developed in a module so that further integration and extension into other related estimation and construction management systems are made possible.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2004.04a
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• pp.81-86
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• 2004

For the development of system framework which provides multidisciplinary design environment, the integration of analysis codes written in various computer languages, the integration of CAD and DBMS, and the development of complex GUI are indispensible In this study, three different design frameworks which have been developed in Konkuk University with the aids of a company and other university, are compared and analyzed with respect to the analysis code integration method and the module interface technique. Moreover, the way to develop an efficient framework is proposed.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.11
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• pp.180-187
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• 2003

A CAD-based seamless design system for MEMS named DS/MEMS was developed which performs coupled-field analysis, optimal and robust design. DS/MEMS has been developed by means of integrating commercial codes and inhouse code-SolidWorks, FEMAP, ANSYS and CA/MEMS. This strategy results in versatility that means to include various analysis model, corresponding analyses and approximated design sensitivity analysis and user friendliness that design variables are taken to be selectable directly from a CAD model, that the problem is formulated under a window environment and that the manual job during optimization process is almost eliminated. DS/MEMS works on a parametric CAD platform, integrating CAD modeling, analysis, and optimization. Nonlinear programming algorithms, the Taguchi method, and response surface method are made available for optimization. One application problem is taken to illustrate the proposed methodology and show the feasibility of DS/MEMS as a practical tool.