• Title/Summary/Keyword: Cad Program

Search Result 622, Processing Time 0.024 seconds

Aspherical Lens Design and Injection Mold Analysis Using Extracted Shape Information (형상정보 추출을 통한 비구면 렌즈 설계 및 성형해석에 관한 연구)

  • Song, K. H.;Kim, B. C.;Yoon, H. S.;Yang, J. K.;Kim, K. B.;Xiao, H.;Cho, M. W.
    • Transactions of Materials Processing
    • /
    • v.24 no.6
    • /
    • pp.437-442
    • /
    • 2015
  • The development of polishing technology has enabled the production of injection molds with high quality surfaces and shapes. For products such as mobile phones which require high quality performance the use of plastic materials has many constraints such as shrinkage and deflection. The purpose of the current research is to use reverse engineering in order to find and analyze the data of a selected aspherical lens and then creating a process to design an improved lens. Additionally, the improved lenses are subject to molding analysis. In order to solve this problem, the lens construction program, Zemax, was used to analyze and optimize performance. In the case of optimization, the object was to eliminate spherical aberration and to find good MTF data. The result of the optimization data was similar to the MTF data found from a random lens. Specific resin and analysis conditions were selected and CAD modeling was done to enhance the injection molding analysis.

Optimization Approach for a Catamaran Hull Using CAESES and STAR-CCM+

  • Yongxing, Zhang;Kim, Dong-Joon
    • Journal of Ocean Engineering and Technology
    • /
    • v.34 no.4
    • /
    • pp.272-276
    • /
    • 2020
  • This paper presents an optimization process for a catamaran hull form. The entire optimization process was managed using the CAD-CFD integration platform CAESES. The resistance of the demi-hull was simulated in calm water using the CFD solver STAR-CCM+, and an inviscid fluid model was used to reduce the computing time. The Free-Form Deformation (FFD) method was used to make local changes in the bulbous bow. For the optimization of the bulbous bow, the Non-dominated Sorting Genetic Algorithm (NSGA)-II was applied, and the optimization variables were the length, breadth, and angle between the bulbous bow and the base line. The Lackenby method was used for global variation of the bow of the hull. Nine hull forms were generated by moving the center of buoyancy while keeping the displacement constant. The optimum bow part was selected by comparing the resistance of the forms. After obtaining the optimum demi-hull, the distance between two demi-hulls was optimized. The results show that the proposed optimization sequence can be used to reduce the resistance of a catamaran in calm water.

Development of Exit Burr Identification Algorithm on Multiple Feature Workpiece and Multiple Tool Path (복합형상 및 다중경로에 대한 Exit Burr 판별 알고리듬의 개발- 스플라인을 포함한 Exit Burr의 해석 -)

  • Kim, Ji-Hwan;Lee, Jang-Beom;Kim, Young-Jin
    • IE interfaces
    • /
    • v.18 no.3
    • /
    • pp.247-252
    • /
    • 2005
  • In the automated production environment in the present days, the minimization of manual operation becomes a very important factor in increasing the efficiency of the production system. The exit burr produced through the milling operation on the edge of workpiece usually requires manual deburring process to enhance the level of precision of the resulting product. So far, researchers have developed various methods to understand the formation of exit burr in cutting process. One method to analytically identify the formation of exit burr was to use the geometrical information of CAD and CAM data used in automated machining. This method, in turn, generated the information resulting from the analysis such as burr type, cutting region, and exit angle. Up to now, the geometrical data were restricted to the single feature and single path. In this paper, a method to deal with the complicated geometric features such as line segment, arc, hole, and spline will be presented and validated using the field data. This method also deals with the complex workpiece shape which is a combination of multiple features. As for the cutting path, multiple tool path is analyzed in order to simulate the real cutting process. All this analysis is combined into a Windows based software and real data are used to validate the program in the conclusion.

Development of Men Slacks Pattern Using 3D Scan Data (3차원 인체형상 스캔데이터를 이용한 남자 바지패턴 설계)

  • Sohn, Boo-Hyun
    • Journal of the Korean Home Economics Association
    • /
    • v.46 no.9
    • /
    • pp.137-146
    • /
    • 2008
  • This study was conducted in order to spread out lower body 3D scan data of men in their twenties. The aim was to achieve slacks pattern with ease allowance through comparison with existing flat patterns. For conversion of 3D scan data into 20 pattern, reference lines were established by using Rapid Foam in 3D shape analysis software. 2C-AN program and Yuka CAD were used to convert 20 pattern earned with straight posture of 3D scan data into slacks pattern by using Triangle Simplification & Runge-Kutta Method. In order to achieve this we needed to set a line 9cm below the hip line, to array vertex of each block to crease line while maintaining the horizontal line. And then we needed to set ease allowance in back crotch and to set waist circumference or hip circumference ease allowance in side seam of slacks. Results showed that long front crotch length can be achieved if 3D scan data is compared with 20 existing flat pattern. Slacks pattern that raise front crotch by about 1.5cm compared to back crotch and also possess ease allowance in back crotch area are great in appearance evaluation.

COMPUTATION OF FLOW AROUND A SHIP USING A SURFACE INTERPOLATED FROM STATION LINES (선체 횡단면 곡선 보간에 의한 표면 생성 및 유동 계산)

  • Kim, Hyun-Sik;Shin, Sangmook
    • Journal of computational fluids engineering
    • /
    • v.20 no.4
    • /
    • pp.21-27
    • /
    • 2015
  • Flow field around the KRISO 3600TEU container ship is computed using a surface generated based on interpolations of station lines, which are given in a body plan of the ship, without using any CAD program. An interpolation method is suggested based on inscribed circles to generate curves between two neighboring station lines. The interpolated surface is saved in a STL format to use the snappyHexMesh utility of the openfoam. Computed resistance of the ship is compared with experimental and other computational results and the effects of the interpolation of neighboring station lines on the computed resistance are investigated. The suggested method is applied to calculate the flow field around a submarine with appendages. The surface triangulations for the hull and the appendages are generated without consideration of each other, then those surface triangulations are simply combined to provide a grid generator with the body boundary. The junctures of the hull and the appendages are identified automatically during the grid generation procedure. Tip vortex is captured, which travels downstream from the tip of the appendages.

CFD Analysis on Stent Shape to Reduce Blood Flowing into Cerebral Aneurysm (뇌동맥류 혈액유입 저감을 위한 스텐트 형상에 관한 전산유체해석)

  • Yeo, Dong-Hyeon;Park, Dong-Gyu;Byon, Sang-Min
    • Journal of the Korean Society of Manufacturing Process Engineers
    • /
    • v.16 no.1
    • /
    • pp.42-50
    • /
    • 2017
  • A cerebral aneurysm is a ballooning arising from a weakened area in the wall of a blood vessel in the brain. In this study, the flow analysis of the blood vessel, including the cerebral aneurysm and the stent, was conducted to investigate the effect of the stent shape on reduction of blood flowing into the cerebral aneurysm. We used the Carreau model to describe Non-Newtonian behaviors of blood flow. Two kinds of stents, which had different cross angles were modelled by the commercial CAD program and the geometries of those stents were reflected in the analysis domain of the blood vessel. From the results of the flow analysis, we found that the blood flowing into the cerebral aneurysm was decreased as the cross angle of the stent was decreased.

A Study of Algorithm for Press Layout Setup using Product design Data (제품 설계 데이터를 이용한 프레스 금형 Layout 설정을 위한 알고리즘에 관한 연구)

  • 이상준
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
    • /
    • 2000.04a
    • /
    • pp.391-396
    • /
    • 2000
  • Today most companies are designing their automobile shapes by using 3 dimensional CAD software, CATIA. And they used to design 2 dimensional press dies to do some elastic work on their products, but they are currently trying to make use of dimensional software, Pro-Engineer. In this case, they have to change the 3 dimensional product design data to the proper format data for the following process. This paper will show the data loss and the deformation during data transfer between CATIA and Pro-Engineer, and then suggest a solution for these problems. Product's surface will be automatically placed by automatic press tipping angle setting in CATIA to prevent the product from being stuck in the press die. The 2 dimensional section view which is based on the tipping angle setting is created by Z-map. And, to remove the data loss and the data deformation in pro-Engineer, the product surface are delivered to the next process after it is changed to the 2 dimensional Z-map curves in CATIA. finally, this paper suggests an algorithm to develop the automatic design program for the press layout which regenerates product shape surface from the previous process.

  • PDF

Minimum cost design of overhead crane beam with box section strengthened by CFRP laminates

  • Kovacs, Gyorgy;Farkas, Jozsef
    • Structural Engineering and Mechanics
    • /
    • v.61 no.4
    • /
    • pp.475-481
    • /
    • 2017
  • An overhead travelling crane structure of two doubly symmetric welded box beams is designed for minimum cost. The rails are placed over the inner webs of box beams. The following design constraints are considered: local buckling of web and flange plates, fatigue of the butt K weld under rail and fatigue of fillet welds joining the transverse diaphragms to the box beams, fatigue of CFRP (carbon fibre reinforced plastic) laminate, deflection constraint. For the formulation of constraints the relatively new standard for cranes EN 13001-3-1 (2010) is used. To fulfill the deflection constraint CFRP strengthening should be used. The application of CFRP materials in strengthening of steel and concrete structures are widely used in civil engineering applications due to their unique advantages. In our study, we wanted to show how the mechanical properties of traditional materials can be improved by the application of composite materials and how advanced materials and new production technologies can be applied. In the optimization the following cost parts are considered: material, assembly and welding of the steel structure, material and fabrication cost of CFRP strengthening. The optimization is performed by systematic search using a MathCAD program.

A Study on the Ship Cargo Hold Structure Data Model Based on STEP (STEP을 근거로 한 선체화물창부 구조 데이터 모델에 관한 연구)

  • 박광필;이규열;조두연
    • Korean Journal of Computational Design and Engineering
    • /
    • v.4 no.4
    • /
    • pp.381-390
    • /
    • 1999
  • In this study, a pseudo ship structure data model for the :.hip cargo hold structure based on STEP is proposed. The proposed data model is based on Application Reference Model of AP218 Ship Structure which is the model that specifies conceptual structures and constraints used to describe the information requirements of an application. And the proposeddata model refers the Ship Common Model framework for the model architecture which is the basis for ongoing ship AP development within the ISO ship-building group and the ship product definition information model of CSDP research project for analyzing the relationship between ship structure model entities. The proposed data model includes Space, Compartment. Ship Structural System, Structural Part and Structural Feature of cargo hold. To generate this data model schema in EXPRESS format, ‘GX-Converter’was used which enables user to edit a model in EXPRESS format and convert schema file in EXPRESS format. Using this model schema, STEP physical file containing design data for ship cargo hold data structure was generated through SDAI programming. The another STEP physical file was also generated containing geometry data of ship cargo hold which was extracted and calculated by SDAI and external surface/surface intersection program. The geometry information of ship cargo hold can be then transferred to commercial CAD system, for example, Pro/Engineer. Examples of the modification of the design information are also Presented.

  • PDF

A study on the Computer-Aided Design of steam ejector (증기 이젝터의 자동설계를 위한 전산프로그램의 개발)

  • 김경근;김용모;강신돌
    • Journal of Advanced Marine Engineering and Technology
    • /
    • v.11 no.3
    • /
    • pp.53-60
    • /
    • 1987
  • Steam ejector is a equipment which compresses the gases to desired discharge pressure. It is widely used for the evacuation systems because of its high working confidence. And recently it is used as the thermo-compressors in the various energy saving systems. Steam ejector is constructed of three basic parts; a suction chamber, a motive nozzle and a diffuser. The high velocity stream jet of steam emitted by the motive nozzle creats suction chamber, which draws the low pressure gases. The diffuser converts the kinetic energy of high velocity flow to pressure energy. It is not easy to determine the dimensions of a steam ejector met to the desired design condition, because that the expected suction rates must be obtained by reapeating the complicate calculation. And also such a calculation is concomitant with geometrical analysis for suction part and diffuser based on the stability of steam flow. Therefore, it is considered that the Computer-Aided Design (CAD) of steam ejector is a powerful design method. In this paper, computer program for steam ejector design is developed based on the theoretical research and the previous experimental results. And the determinating method of diffuser inlet angle and the velocity development profile of suction gas along to the diffuser are suggested. The validity of the development profile of suction gas along to the diffuser are suggested. The validity of the developed computer results with other's for the practical design calculation of a manufactured steam ejector.

  • PDF