• 제목/요약/키워드: Flow Forming

검색결과 653건 처리시간 0.03초

액상과 고상의 유동현상을 고려한 레오로지 성형공정의 표면결함예측을 위한 응고해석 (Solidification Analysis for Surface Defect Prediction of Rheology Forming Process Considering Flow Phenomena of Liquid and Solid Region)

  • 서판기;정영진;강충길
    • 대한기계학회논문집A
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    • 제26권10호
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    • pp.1971-1981
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    • 2002
  • Two-dimensional solidification analysis during rheology forming process of semi-solid aluminum alloy has been studied. Two-phase flow model to investigate the velocity field and temperature distribution is proposed. The proposed mathematical model is applied to the die shape of the two types. To calculate the velocities and temperature fields during rheology forming process, the each governing equations correspondent to the liquid and solid region are adapted. Therefore, each numerical model considering the solid and liquid coexisting region within the semi-solid material have been developed to predict the defects of rheology forming parts. The Arbitrary Boundary Maker And Cell(ABMAC) method is employed to solve the two-Phase flow model of the Navier-Stokes equation. Theoretical model basis of the two-phase flow model is the mixture rule of solid and liquid phases. This approach is based on using the liquid and solid viscosity. The Liquid viscosity is pure liquid state value, however solid viscosity is considered as a function of the shear rate, solid fraction and power law curves.

편리한 입력방식의 단조공정해석을 위한 CAMPform 2D의 Preprocessor 개발 (Development of CAMPform2D Preprocessor for Forming Process U sing Convenient Input Method)

  • 박성균;이상헌;이강수
    • 한국CDE학회논문집
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    • 제9권2호
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    • pp.133-142
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    • 2004
  • CAMPfonn2D is a Finite Element Method (FEM) based process simulation system designed to analyze two dimensional (2D) flow of various metal forming processes. It enables designers to analyze metal forming processes on the computer rather than the shop floor using trial and error and provides vital information about material and thermal flow during the forming process to facilitate the design of products. CAMPfonn2D can be used by companies, research institutes and industrial applications to analyze forging, extrusion, drawing, heading, upsetting and many other metal forming processes. Also, process simulation using CAMPfonn2D can be instrumental in cost, quality and delivery improvements at leading companies. Today's competitive pressures require companies to take advantage of every tool for rapid manufacturing of well-designed product. So, the preprocessor of simulation program must be easy to use to speed-up design. In this paper, we introduce new version of Preprocessor and show how easy to use it. And, Preprocessor will prove itself to be easy and extremely effective.

초소성 판재 성형을 위한 유한요소 해석 및 실험에 관한 연구 (A Study on the Superplastic Sheet Forming by the FEM and Experiment)

  • 이승준;이정환;이영선
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2000년도 춘계학술대회논문집A
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    • pp.866-872
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    • 2000
  • Superplastic forming processes by characteristic of low flow stress and high elongation have advantages to reducing on production cost and weight because of the product of complex form could be made in one part. However superplastically termed part has a characteristic of non-uniform thickness distribution along forming direction. Especially. since the thickness distribution affects on mechanical properties of product. the uniform thickness is very important. There are two solution procedure of implicit and explicit procedure to analyze the superplastic forming. In this study to analyze the thickness distribution two kinds of commercial programs of DEFORM and PAM-STAMP which implicit and explicit code are used respectly. The results from the two Programs were compared with eath other As a result implicit code were more suitable than explicit code for superplastic forming analysis.

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단붙이 로드의 성형에서 소재유동에 관한 해석 (Numerical analysis on the material flow in stepped rod forming)

  • 고병두;강동명;이하성
    • Design & Manufacturing
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    • 제2권2호
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    • pp.43-47
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    • 2008
  • This paper is concerned with the analysis of material flow characteristics of stepped rod forming. The analysis in this paper concentrated on the evaluation of the design parameters for deformation patterns of tube forming, load characteristics, extruded length, and die pressure. The design factors such as punch nose radius, die corner radius, friction factor, and punch face angle are involved in the simulation. The stepped rod forming is analyzed by using a commercial finite element code. This simulation makes use of stepped rod material and punch geometry on the basis of punch geometry recommended by International Cold Forging Group. As radius ratio is large, forming load was reduced but extruded length ratio was increased.

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유도가열을 이용한 강판성형공정에서 유도코일 형상의 효과 (Effects of Inductor Shape in Steel Forming Process with High Frequency Induction Heating)

  • 양영수;배강열;신희윤
    • Journal of Welding and Joining
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    • 제26권4호
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    • pp.66-72
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    • 2008
  • Because of high intensity and easy controllability of the heat source, high frequency induction heating has been concerned and studied for the steel forming process in the ship building industry. However, the heating and forming characteristics have to be further properly modelled and analyzed for the process to be utilized with its optimal working parameters. In this study, a modelling with thermo-elasto-plastic analysis is performed using the FEM to study heat flow and deformation of the steel plate during the forming process with the electro-magnetic induction heating. The numerical model is then used to study the effect of the inductor shape on the magnitude of angular deformation of the plate during the forming process. It is revealed that the square shape of inductor induces the largest deformation among the rectangular inductors.

알루미늄재료의 Rheo-forming을 위한 성형공정해석 (Process Analysis for Rheo-Forming of Aluminum Materials)

  • 서판기;정영진;정경원;강충길
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 2001년도 춘계학술대회 논문집
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    • pp.124-128
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    • 2001
  • Two-dimensional solidification analysis during rheology forming process of semi-solid aluminum ahoy has been studied Two-phase fluid flow model to investigate the velocity field and temperature distribution is proposed. The unposed mathematical model is applied to the die shape of the two type. To calculate the velocities and temperature fields during rheology forming process, the each governing equation correspondent to the liquid and solid region are adapted. Theoretical model on the basis of the two-phase flow model is the mixture rule of solid and liquid phases. This approach is based on the liquid and solid viscosity.

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탄성 변형 영역을 고려한 비정상 평면 변형 이상 공정 이론 (Nonsteady Plane-strain ideal forming with elastic dead zone)

  • 이원오;정관수
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 2004년도 춘계학술대회 논문집
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    • pp.190-193
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    • 2004
  • Ever since the ideal forming theory has been developed fur process design purposes, application has been limited to sheet forming and, for bulk forming, to two-dimensional steady flow. Here, application for the non-steady case was performed under the plane-strain condition based on the theory previously developed. In the ideal flow, material elements deform following the minimum plastic work path (or mostly proportional true strain path) so that the ideal plane-strain flow can be effectively described using the two-dimensional orthogonal convective coordinate system. Besides kinematics, for a prescribed final part shape, schemes to optimize a preform shape out of a class of initial configurations and also to define the evolution of shapes and boundary tractions were developed. Discussions include the two problematic issues on internal tractions and the non-monotonous straining. For demonstration purposes, numerical calculations were made for a bulk part under forging.

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열간프레스성형에서의 기계적 물성 측정 (Measurement of Mechanical Properties for Hot Press Forming)

  • 안강환;유동훈;석동윤;김홍기;박성호;정관수
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 2009년도 춘계학술대회 논문집
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    • pp.450-453
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    • 2009
  • In order to overcome drawbacks of the advanced high strength steel such as inferior formability and large springback, the hot press forming process(HPF) has been being applied for forming of automotive sheet parts. Good formability and dimensional accuracy without springback as well as good crash performance of final products are the advantages of the HPF process. In this work, a method to characterize the mechanical properties of the HPF steel was developed based on the simple tension test at high temperatures and its finite element analysis, while it was applied to obtain strain rate and temperature dependent flow curves of the HPF steel. The final flow curves were represented by utilizing the Johnson-Cook type equation both in uniform and post-uniform deformation regions.

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자유 단조의 소성불안정 유동에 관한 연구 (A Study on the Pladstic Instable Flow in Free Forging)

  • 이용성
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 2000년도 춘계학술대회논문집
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    • pp.96-100
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    • 2000
  • It is difficult to predict material behavior of forming process because the plastic instable flow phenomenon happens in practical forming process I. e. upsetting backward extrusion piercing indentation. In view of the direct relationship between instable material flow and quality defects of the products we should find out their phenomena, In this study we introduced the plastic spin and the kinematic hardening considering the kinematic hardening constitutive equation for rate-dependent material. Also analysis of upset forging is carried out using the rigid plastic FEM with Al7075

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