• 제목/요약/키워드: Forming pressure

검색결과 665건 처리시간 0.027초

계층적 접촉 탐색방법을 이용한 3-D 초소성 성형/확산접합의 공정설계(I) (Analysis of 3-D Superplastic Forming/Diffusion Bonding Process Using a Hierarchical Contact Searching Method(I))

  • 강영길;송재선;홍성석;권용남;이정환;김용환
    • 소성∙가공
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    • 제16권2호
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    • pp.138-143
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    • 2007
  • Superplastic forming/diffusion bonding (SPF/DB) processes were analyzed using a 3-D rigid visco-plastic finite element method. A constant-triangular element based on membrane approximation and an incremental theory of plasticity are employed for the formulation. The coulomb friction law is used for interface friction between tool and material. Pressure-time relationship for a given optimal strain rate is calculated by stress and pressure values at the previous iteration step. In order to improve the contact searching, hierarchical search algorithm has been applied and implemented into the code. Various geometries including sandwich panel and 3 sheet shape for 3-D SPF/DB model are analyzed using the developed program. The validity fer the analysis is verified by comparison between analysis and results in the literature.

플래시 발생 억제형 신발 중창 금형 개발에 관한 연구 (A Study on the Development of Shoe Midsole Mold for Flash-less)

  • 허관도;여홍태;최영
    • 한국정밀공학회지
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    • 제22권1호
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    • pp.109-114
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    • 2005
  • In this study, to develop a flash-less mold for forming of shoe-midsole, experiments and forming analysis were carried out. In order to reduce the extra-materials, the final preform has been modified by the experiment of pressure forming at the room temperature. To measure the contact status of parting surface of mold, the pressure film has been used. The midsole mold of the wedge structure type has been developed for the improvement of the contact status. The vertical pressing mold structure was introduced for the production of a flash-less midsole. By the investigation, flash of shoe-midsole was considerably reduced.

Side Member 관재 하이드로포밍 성형해석 (Forming Analysis on the Tubular Hydroforming of Side Member)

  • 박재헌;최이천;오영근
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 2001년도 춘계학술대회 논문집
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    • pp.54-58
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    • 2001
  • In recent years, hydroforming technology has been one of the most important technology in automotive industry in the points of weight saving, cost reduction and qualify improvement. However, compared with traditional metal forming technology, hydroforming has much fewer information in experience and empirical knowledge. But we don't have my sufficient time and money to produce hydroforming products using real blank directly Therefore Simulation is essential in hydrofonrung technology development. In this paper, we simulate the side member as the tubular hydroforming technology. The manufacturing process of side member' consists of pre_bending, pre_forming, and hydroforming of a thin tube. Variables such as internal pressure, end feeding, and tool geometry are optimized to improve the forming safety. And we simulate side member according to several lubricant conditions. from those simulations, we find that strain distributions can be reduced well by internal pressure and end feeding control, and lubrication is the most important thing in hydroforming process.

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Ti-6Al-4V 합금의 초소성 벌지성형에 미치는 배압력의 영향 (A Study on the Effect of Back Pressure on the Superplastic Bulge Forming of Ti-6Al-4V Alloy)

  • 송유준;이종수
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 1997년도 춘계학술대회논문집
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    • pp.175-178
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    • 1997
  • A modified Mukerjee's model considering the microstructural evolution was developed to study the superplastic bulge forming process of Ti-6Al-4V alloy. Through the microstructual observation after deformation, it was found that the grain growth rate of uniaxially tested specimens was different from that of biaxially deformed specimens. From this result, bulge forming experiments with and without back pressure were performed to examine the grain growth behavior and to compare the results of biaxial test with those of triaxial test. Good agreement between the prediction by a modified Mukerjee's model and the experimental measurements was obtained for bulge profile and thickness distribution.

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간접가압방식에 의한 전자교반응용 암 부품 개발 (Development of Arm Part by Indirect Press Process with Electromagnetic Stirring Application)

  • 고재홍;서판기;강충길
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 2005년도 추계학술대회 논문집
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    • pp.340-343
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    • 2005
  • This paper focuses on an rheo-forming of arm part fabricated by electromagnetic stirring system (EMS). This forming process take place under high pressure of high pressure die casting and thin walled casting is possible. Also the productivity is better than low pressure die casting because of shorter cycle time. The advantages of rheo-forming are performed in the semi solid state with laminar flow and the gas content is low, which makes welding possible. Therefore this research applies for arm part with EMS and has investigated the mechanical propriety after T6 and T5 heat-treatment.

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전.후방 캔 압출공정의 성형특성 연구 (A Study on the Forming Characteristics of Forward and Backward Extrusions)

  • 심지훈;최호준;옥정한;함병수;황병복
    • 한국정밀공학회지
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    • 제22권3호
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    • pp.86-92
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    • 2005
  • In this paper a forward-backward can extrusion process are analyzed by using rigid-plastic FEM simulation. FEM simulation is conducted to investigate forming characteristics such as deformation modes fur different process parameters. Design parameters such as thickness ratio, punch angle, friction factor and diameter ratio are selected to study the effect of them on the pattern of material flow. The analysis is focused mainly on the influences of the design factors on deformation pattern in terms of forming load, extruded length ratio and volume ratio. It is known for the simulation that the forming load, the length ratio and the volume ratio increase as the thickness ratio (TR), the wall thickness in forward direction to that in backward direction, decreases. The various punch angles have slight influence on the forming load. length ratio and volume ratio. However friction factor have little effect on the forming characteristics such as the forming load, volume ratio and so on. In addition the forming load increases as diameter ratio (DR), the outer diameter of a can in forward direction to that in backward direction, increases. Furthermore the extruded length ratio is lowest with a certain value of DR=0.85 among diameter ratios. Pressure distribution exerted on the die-material interface is illustrated schematically.

액압성형 시험을 통한 알루미늄 튜브 재료의 성형한계도 (Forming Limit Diagram of an Aluminum Tube Through Hydroforming Tests)

  • 김정선;이진규;박종연;이동재;김헌영;김형종
    • 소성∙가공
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    • 제14권6호
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    • pp.514-519
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    • 2005
  • A tube hydroformability testing system was designed and fabricated enabling to apply the forming condition along arbitrarily pre-programmed internal pressure-axial feed path. The free-bulging and T-forming tests were carried out on the extruded aluminum (A6063) tube specimens with 40.6 mm outer diameter and 2.25 mm thickness. Nine different combinations of internal pressure and axial feed, yielding different strain paths from one another, were taken into consideration in order to induce bursting at various deformation modes. Major and minor strains were automatically measured from deformed grids around the fracture using a stereo-vision-based surface strain measurement system, named ASIAS. The forming limit diagram of the A6063 tube material was successfully obtained. Most of the data points acquired from free bulging and T-forming tests appeared in the range of negative minor strain on the FLD and are mostly located near the strain paths calculated from explicit finite element simulations. The forming limit obtained from tests after pre-tension was considerably lower than that from tests without pre-tension, which showed the strain path-dependency of the forming limit as well known in the sheet forming fold.

성형 압력에 따른 T800 탄소섬유/에폭시 복합재료의 평면 내.외 물성 변화에 대한 연구 (A study on the variation of in-plane and out-of-plane properties of T800 carbon/epoxy composites according to the forming pressure)

  • 박명길;조성겸;장승환
    • Composites Research
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    • 제23권6호
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    • pp.61-66
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    • 2010
  • 본 논문에서는 필라멘트 와인딩 시 장력에 의해 압밀을 유발하는 압력을 선행연구자들의 연구를 참조하여 결정한 후 T800 탄소섬유/에폭시 복합재료의 기본적인 물성과 성형압력 변화에 따른 면 내 외의 물성 변화를 측정하였다. 실험 시편은 오토클레이브 진공백 성형을 통해 압력(절대압력 0.1MPa, 0.3MPa, 0.7MPa)을 조절하여 제조되었다. 모든 시편은 적층판 형태로 정화된 후 워터젯을 이용하여 시편 모양으로 절단되었으며, 층간 전단시편의 V-노치는 밀링가공을 통하여 제작되었다. 평면 내 물성을 위해 다양한 인장실험이 실시되었으며, 평면 외 물성을 측정하기 위해 층간 전단 실험이 수행되었다 성형압력과 물성 변화를 관련시키기 위해 시편의 섬유 부피분율을 측정하였다. 본 연구에서 측정된 물성은 동일한 탄소섬유 (T800 탄소섬유)를 사용하여 필라멘트 와인딩 공정으로 제작되는 차량용 Type III 수소저장용기의 설계에 유용하게 활용될 수 있을 것으로 기대된다.

An approach to improve thickness distribution and corner filling of copper tubes during hydro-forming processes

  • GhorbaniMenghari, Hossein;Poor, Hamed Ziaei;Farzin, Mahmoud;Alves De Sousa, Ricardo J.
    • Structural Engineering and Mechanics
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    • 제50권4호
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    • pp.563-573
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    • 2014
  • In hydroforming, the general technique employed to overcome the problem of die corner filling consist in increasing the maximum fluid pressure during the forming process. This technique, in other hand, leads to other difficulties such as thinning and rupturing of the final work piece. In this paper, a new technique has been suggested in order to produce a part with complete filled corners. In this approach, two moveable bushes have been used. So, the workpiece moves driven by both bushes simultaneously. In the first stage, system pressure increases until a maximum of 15 MPa, providing aninitial tube bulge. The results showed that the pressure in this stage have to be limited to 17 MPa to avoid fracture. In a second stage, bushes are moved keeping the constant initial pressure. The punches act simultaneously at the die extremities. Results show that the friction between part and die decreases during the forming process significantly. Also, by using this technique it is possible to produce a part with reasonable uniform thickness distribution. Other outcomes of applying this method are the lower pressures required to manufacture a workpiece with complete filled corners with no wrinkling.

박판페어를 이용한 하이드로포밍 공정의 수치적 및 실험적 해석 (Numerical and Experimental Analysis of Hydroforming Process of Sheet Metal Pairs)

  • 김태정;양동열;한수식;남재복;진영술
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 2001년도 추계학술대회 논문집
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    • pp.50-53
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    • 2001
  • Hydroforming process has become an effective manufacturing process because it can be adaptable to forming of complex structural components. Tube hydroforming has been successfully developed in the real industrial field by many researchers. However, there still remains the constraint about shape which can be manufactured by tube hydroforming. In order to improve this constraint of shape and formability of conventional sheet metal forming, hydroforming process of sheet metal pairs becomes an important technology. In the present work, the finite element analysis of hydroforming process of sheet metal pairs is presented. After basic study about experimental parameters based on numerical analysis, hydroforming process of sheet metal pairs is developed which uses hydraulic pressure as a main forming source.

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