• Title/Summary/Keyword: Flatness deformation

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Prediction Technology of Reverse Setting Block Shape with Inherent Strain Method and Re-meshing Technology (고유 변형도법과 리메슁 기술을 접목한 블록의 역세팅 형상 예측기술)

  • Hyun, Chung-Min;Choi, Han-Suk;Park, Chang-Woo;Kim, Sung-Hoon
    • Journal of Ocean Engineering and Technology
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    • v.31 no.6
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    • pp.425-430
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    • 2017
  • In order to reduce the cost of corrections and time needed for the block assembly process, the reverse setting method is applied for a back-heated block to neutralize deck deformation. The proper reverse setting shape for a back-heated block to correct deformation improved the deck flatness, but an excessive amount of reverse setting could inversely affect the flatness of the block. A prediction method was developed for the proper reverse setting shape using a back-heated block, considering the complex geometry of blocks, thickness of the deck plate, and thermal loading conditions such as welding and back-heating. The prediction method was developed by combining the re-meshing technique and inherent strain-based deformation analysis using the finite element method. Because the flatness deviation was decreased until the lower critical point and thereafter it tended to increase again, the optimum value for which the flatness was the best case was selected by repeatedly calculating the predefined reverse setting values. Based on this analysis and the study of the back-heating deformation of large assembly blocks, including the reverse setting shape, the mechanism for selecting the optimum reverse setting value was identified. The developed method was applied to the actual blocks of a ship, and it was confirmed that the flatness of the block was improved. It is concluded that the developed prediction method can be used to predict the optimum reverse setting shape value of a ship's block, which will reduce the cost of corrections in the construction stage.

Structural Analysis of Cabinet in Built-in Side-by-Side Refrigerator and Evaluation of Door Height Difference and Door Flatness Difference (빌트인 양문형 냉장고의 캐비닛 구조해석 및 도어 상하단차와 앞뒤단차의 평가)

  • Lee, Boo-Youn
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.17 no.2
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    • pp.30-36
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    • 2018
  • Since the freezer compartment and the refrigerating compartment are located side by side in a side-by-side refrigerator, the problems of the door height difference (DHD) and door flatness difference (DFD) have been constantly raised. Deformation of the cabinet of a built-in side-by-side refrigerator under food and thermal loads was analyzed by the finite element software ANSYS. The DHD and DFD, occurring due to the deformation of the cabinet, evaluated. From the results of the analysis of the cabinet, the 3D CAD software CATIA was used to geometrically translate and rotate the freezing and refrigerating compartment doors, in consideration of the displacement of the hinge fastening point. Then, the coordinates of two points on the upper corner of the doors were determined, and the DHD and DFD were obtained. It found that the thermal load, occurring under normal operation conditions, decreases the door height difference, but increases the door flatness difference. Values of the analyzed DHD and DFD appear smaller than the acceptance criteria used by the refrigerator manufacturer.

A Study on the Cross Rolling for Improvement of Flatness of Plate (판재의 편평도 향상을 위한 교차압연에 관한 연구)

  • Nam K. O.;Seo K. S.;Rho B. R.;Hong S. I.
    • Transactions of Materials Processing
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    • v.14 no.1 s.73
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    • pp.43-48
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    • 2005
  • The production of metal strip with uniform thickness and flatness are two important problems associated thin strip rolling. The thickness and flatness of strip are affected by the flattening of contact surface between strip and roll, the elastic recovery and the bending of roll. Especially, the flatness of the strip is greatly affected by bending deflection of roll. The roll must be designed considered the elastic deformation of roll. This study describes the measurement of thickness and flatness of strip and shows the crown roll for producing flat strip. But it is difficult to produce the crown roller. The cross rolling that is a simple method which can produce the flat strip is introduced and it is found the optimal cross angle for improvement of flatness of plate. These problems are solved by the MARC code on the basis of elastic-plastic material and the updated Lagrangian formulation.

A study on shearing die design for window roller housing and die manufacture (창호용 롤러 하우징의 전단금형 설계 및 제작에 관한 연구)

  • Kim, Sei-hwan;Choi, Kye-kwang
    • Design & Manufacturing
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    • v.8 no.1
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    • pp.35-39
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    • 2014
  • Window roller housings are durable because high-quality source materials such as stainless steel is used in making them. After a series of precise structure analysis, their design is optimized. They are subject to repetitive driving tests of more 100,000 times, durability tests, impact resistance tests, corrosion tests and others. For a long time, gaps often occur in press molded products owing to serious squareness deformation and flatness deformation of them. Severe burrs in press molded products require frequent grinding, which leads to short life cycle and rough or unreliable movement of assembled roller housing, which, in turn, causes product defects. This study focuses on developing measures to resolve existing defects and to improve lifespan of dies by designing and making a window roller shearing die.

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Shapes and Thermomechanical Analyses of a Hot Roll for Manufacturing Electrodes of Polymer Batteries (폴리머 배터리 전극제조용 압연 고온롤 표면의 형상 및 유한요소 열변형 해석)

  • Kim, Cheol;Jang, Dong-Sue;Yu, Seon-Jun
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.31 no.8
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    • pp.847-854
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    • 2007
  • The battery electrode of a mobile phone is made of layered polymer coated on aluminum foils and the hot rolling process is applied to increase the density per volume of an electrode for a high capacity battery. The flatness of batteries surfaces should be less than $2{\mu}m$. To satisfy the required flatness, the deformation of roll surface due to bending and heating of the roll should be minimized. Complicated hot oil paths of $100^{\circ}C$ inside the roll are required for heating the polymer layers. FEA was used to calculate thermal deformations and temperatures distributions of the roller. Based on FEA, a modified surface curvature called a crown roll was suggested and this gave the area of 30% improved flatness compared with a flat roll. The flat roll satisfied the flatness of $2{\mu}m$ in the length of 340 mm and the crown roll resulted in the longer length of 460 mm. Experiments to measure the temperature distribution and thermal strain were performed and compared with FEA. There were only 6% difference between two results.

Analysis of Door Height Difference and Door Flatness Difference of Built-in Side-by-Side Refrigerator Using Cabinet-Door Integrated Model (캐비닛-도어 통합모델을 이용한 빌트인 양문형 냉장고의 도어 상하단차와 앞뒤단차 해석)

  • Lee, Boo-Youn
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.17 no.5
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    • pp.76-83
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    • 2018
  • A cabinet-door integrated finite element model was constructed for a built-in side-by-side refrigerator with an ice dispenser, and its deformation was analyzed using the ANSYS finite element software. As loads, the food load needed to fill in the cabinet and doors and the thermal load occurring during normal operation conditions were taken into consideration. The door height difference (DHD) and door flatness difference (DFD) between the two doors of the freezing and refrigerating compartments were derived. The DHD and DFD under the assembled condition without applied loads satisfied the acceptance criteria specified by the refrigerator manufacturer. It appeared that the food load increases the DFD slightly. The thermal load tends to increase the differences because of the thermal deformation, especially the DFD, of the cabinet and doors.

A Study on the Scheme to Maintain the Flatness of MDF According by painting and by thickness to the Environment Humidity (습도환경에서 두께와 도장재별 MDF의 평탄도 유지방안에 대한 연구)

  • Jeong, Jae-Eun
    • Korean Institute of Interior Design Journal
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    • v.16 no.5
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    • pp.98-106
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    • 2007
  • With the recent increase in the amount of interior materials, the medium-density fiberboard(MDF) has continued to be produced at an increasing rate. Accordingly, to prevent the deformation of MDF after its construction, secure the precision of its finishing and improve the performance of its design, this study attempted to investigate the effect of environment humidity conditions on flatness according to the field used in MDF and its relationship to other physical properties. An attempt was made to conduct this study by changing the conditions of surface treatment by moisture and by thickness. For this purpose, it is judged that it is desirable to prevent scheme to maintain the flatness by defining the coefficient of water absorption-induced length change as in the regulation on low-density soft fiberboard and adjusting the standard for wet bending strength upward. It is thought that is further studies will be conducted about the effect of material, adhesive and thermal pressure condition, production system and processing method used in MDF on its scheme to maintain the flatness and changes in length and thickness expansion.

A Study on the Door Height Difference of the SBS Refrigerator (양문여닫이 냉장고에서 도아의 단차영향 연구)

  • Shin, Kwang-Cheol;Che, Soo-Won
    • Proceedings of the KSME Conference
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    • 2004.11a
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    • pp.528-533
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    • 2004
  • This paper deals with the issue of door height difference (DHD) which occurs for SBS refrigerator necessarily. In order to identify the cause of DHD, analysis of refrigerator structure and entire process from door manufacturing to usage have been investigated. From diverse experiments, it was found that the flatness of the floor was a main causing factor. In order to decrease the DHD , the effects of 6 design parameters to control of cabinet deformation have been investigated by using DOE(design of experiment) and finite element analysis. Based on the correlation equation, it was possible to estimate the DHD for new refrigerator design.

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Analysis of a Hot Rolling Roller and Spring-back of Electrode Materials for Secondary Batteries (이차전지 전극제조용 열간압연롤러와 전극재료의 열 변형 및 스프링백 해석)

  • Kim, Kyung-Sik;Kim, Cheol
    • Proceedings of the KSME Conference
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    • 2008.11a
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    • pp.538-543
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    • 2008
  • A roller with a shaft and hot oil paths for pressing electrodes of polymer batteries were modeled and analyzed by FEM. There are many hot oil tubes in the roller and shaft, through which $72^{\circ}C$ hot oil flows for heating the surface of a roller and shaft. Thermal deformations and temperatures distributions of the roller and shaft were calculated and a convection boundary condition on surfaces was used. The influence of existence of a groove in the shaft on the flatness of a roller surface caused by thermal deformation was investigated. In addition, the amount of spring-back of electrodes under vacuum pressure and heating was calculated after the hot rolling process. It was shown from this study that the groove in one shaft had a favorable effect on the surface flatness.

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12 인치 열-냉 척의 표면 열 변형 해석

  • 이상순;윤지영;김맹권
    • Proceedings of the Korean Society Of Semiconductor Equipment Technology
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    • 2003.12a
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    • pp.207-211
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    • 2003
  • In this study, the geometric modeling has been conducted for a new model of 12 inch hot-cold chuck using three-dimensional solid modeler, SolidWorks. Then, the heat transfer analysis and the thermal deformation analysis using FEM have been performed. The results of the analysis show the temperature distribution and the deformed shape of a new model of 12 inch hot-cold chuck. The evaluation for the surface flatness of a new model has been performed based on the deformed shape obtained from ANSYS.

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