• 소성∙가공
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• 제12권4호
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• pp.320-327
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• 2003

This paper is concerned with forming analysis of Front Side Members and effects of the forming analysis on crash analysis of an auto-body. For efficient forming analysis, equivalent draw-bead restraining forces are calculated with ABAQUS/Standard and then used as the boundary condition in forming simulation. In order to demonstrate the validity of the forming analysis, the thickness variation in the numerical simulation result is compared quantitatively with the one in the real product. Forming histories obtained kom the forming analysis are utilized as the initial condition of the crash analysis for accurate assessment of the crashworthiness. Crashworthiness such as the load-carrying capacity, crash mode and the energy absorption is evaluated and investigated for the identification of forming effects.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2003년도 춘계학술대회논문집
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• pp.266-269
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• 2003

This paper is concerned with a forming analysis of front side members and the application of the forming effect in crash analysis of auto-body. Drawbead restraining forces are calculated with ABAQUS/Strandard in order to identify the boundary condition in forming process. Forming analysis with equivalent drawbead is carried out with LS-DYNA3D. In order to demonstrate the validity of the forming analysis, quantitative comparison of the thickness variation between the real product and the numerical simulation result is carried out. Forming histories obtained from the forming analysis are utilized as the initial condition of the crash analysis for accurate assessment of the crashworthiness.

• 소성∙가공
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• 제15권4호
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• pp.289-294
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• 2006

To reduce automobile parts weight, TWB(tailored welded blank) forming is widely used in panel forming. But products used TWB forming process have many defect, wrinkle, crack and springback. So study of TWB forming process character is very important. In this study one of the current problems of TWB forming was analyzed, especially for the try-out process of inner door panel without frame. A comparison was made between actual measurements and prediction of forming analysis for formability and springback. Also a new analysis die model which have additional plane on die surface was proposed to correct result of forming analysis. This proposed method overcomes the difference for TWB forming result between try-out and analysis.

• Journal of Magnetics
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• 제21권2호
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• pp.215-221
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• 2016

We conducted a phased electromagnetic forming process analysis (EFPA) over time through a coupling of electromagnetic analysis and structural analysis. The analysis is conducted through a direct linkage between electromagnetic analysis and structural analysis. The analysis process is repeated until the electric current is completely discharged by a formed coil. We calculate the forming force that affects the workpiece using MAXWELL, a commercial electromagnetic finite element analysis program. Then, we simulate plastic behavior by using the calculated forming force data as the forming force input to ANSYS, a commercial structure finite element analysis program. We calculate the forming force data by using the model shape in MAXWELL, a commercial electromagnetic finite element analysis program. We repeat the process until the current is fully discharged by the formed coil. Our results can be used to reduce the error in data transformation with a reduced number of data transformations, because the proposed approach directly links the electromagnetic analysis and the structural analysis after removing the step of the numerical analysis of a graph describing the forming force, unlike the existing electromagnetic forming process. Second, it is possible to simulate a more realistic forming force by keeping a certain distance between nodes using the re-mesh function during the repeated analysis until the current is completely discharged by the formed coil, based on the MAXWELL results. We compare and review the results of the EFPA using the peak value of the forming force that acts on the workpiece (which is the existing analysis method), and the proposed phased EFPA over time approach.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2002년도 춘계학술대회 논문집
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• pp.125-128
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• 2002

The automotive industry have made an effort to reduce the weight of vehicle structures with increased safety, while initial model of the final product does not contain any prehistoric effects in a design stave. It takes lots of time to calculate forming effects that have great influences on the energy absorption of structures. In this paper, finite element inverse analysis is adopted to calculate forming effects, such as thickness variation and effective plastic strain as well as an initial blank shape with small amount of computation time. Crash analysis can be directly performed after inverse analysis of the forming process without remeshing scheme. The direct mesh mapping method is used to calculate an initial guess from the sliding constraint surface that is extracted from the die and punch set. Analysis results show that energy absorption of structures is increased with consideration of forming effects and finite element inverse analysis is usefully applicable to calculate forming erects of vehicle structures for the crash analysis.

• 소성∙가공
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• 제13권5호
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• pp.429-434
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• 2004

Manufacturing process for milli components has recently gained researcher's focus with the increasing tendency toward highly integrated and micro-scaled parts for electronic devices. The milli-components need more precise manufacturing process than the conventional manufacturing process since the parts require higher dimensional accuracy than the conventional ones. In order to enhance the forming accuracy and productivity, various forming procedures proposed and studied by many researchers. In this paper, forming analysis of milli-components has been studied with a new micro-former. In modeling of progressive dies, multi-stage forming sequence has been analyzed with finite element analysis by LS-DYNA3D. The analysis proposes the sequential die and part shapes with the corresponding punch force and dimensional accuracy. The analysis also considers the effect of elastic dies on the dimensional accuracy of the formed parts. The analysis result demonstrates that the elastic analysis in the milli-forming process is indispensable for accurate forming analysis. The analysis procedure in the paper will provide good information in design of a new micro-former and milli-component

• Ocean Systems Engineering
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• 제13권4호
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• pp.367-384
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• 2023

Herein, we present the design and development of an efficient finite element analysis model for thermal plate forming in shipbuilding. Double curvature shells in the ship building industries are primarily formed through the thermal forming technique. Thermal forming involves heating of steel plates using heat sources like oxy-acetylene gas torch, laser, and induction heating, etc. The differential expansion and contraction across the plate thickness cause plastic deformation and bending of plates. Thermal forming is a complex forming technique as the plastic deformation and bending depends on many factors such as peak temperature, heating and cooling rate, depth of heated zone and many other secondary factors. In this work, we develop an efficient finite element analysis model for the thermo-mechanical analysis of thermal forming. Different simulations are reported to study the effect of various parameters affecting the process. Temperature dependent properties are used in the analysis and the finite element analysis model is used to identify the critical flame velocity to avoid recrystallization of plate material. A spring connected plate is modeled for structural analysis using spring elements and that helps in identifying the resultant shapes of various thermal forming patterns. Finally, detailed simulation results are reported to establish the efficacy, applicability and efficiency of the designed and developed finite element analysis model.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2004년도 춘계학술대회 논문집
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• pp.118-121
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• 2004

Manufacturing process for milli components has recently gained researcher's focus with the increasing tendency toward highly integrated and micro-scaled parts for electronic devices. The milli-components cannot be formed by the conventional manufacturing process since the parts require higher dimensional accuracy than the conventional ones. In order to enhance the forming accuracy and productivity, various forming procedures proposed and studied by many researchers. In this paper, forming analysis of milli-components has been studied with a new micro-former. In modeling of progressive dies, multi-stage forming sequence has been analyzed with finite element analysis by LS-DYNA3D. The analysis proposes the sequential die and part shapes with the corresponding punch force and dimensional accuracy. The analysis also considers the effect of elastic dies on the dimensional accuracy of the formed parts. The analysis result demonstrates that the elastic analysis in the milli-forming process is indispensable fur accurate forming analysis. The analysis procedure in the paper will provide good information in design of a new micro-former and milli-component.

• 한국해양공학회지
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• 제13권4호통권35호
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• pp.75-81
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• 1999

Roll forming process is simulated with a commercial FEM code LS-DYNA. The rolls are treated as rigid bodies rotating with a constant angular velocity. The strip and the rolls are modeled with 4-node plate elements. It is assumed that the nodes along the front end of the strip move along paths given by sine functions. It is found that the analysis can be applied to the optimal design of forming rolls. With these analyses, it is expected that forming defects can be avoided and process development efforts can be reduced.

• 소성∙가공
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• 제21권4호
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• pp.234-239
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• 2012

This study examines the forming properties and forming loads needed to increase the edge thickness on the external face of a plate using finite element analysis(FEA). Recently, forming optimization techniques within FEA are being extensively used in designing the optimal forming conditions for processes like forging, extrusion, rolling, and spinning. Most of these existing forming operations involve reducing the volume per unit length, but research for increasing volume per unit length is not very extensive. For this study we chose an automotive engine flywheel which is a welded assembly of a plate and a gear with each component having a different thickness. We considered a forming technique to increase the thickness in order to allow the machining of the gear directly on the external face of plate alleviating the need for a weld. To study various forming techniques, we used the finite element method with the flow stress of material and incremental forming steps. We conclude from this study that the analysis of forming properties and forming loads by using the finite element analysis and testing is useful as a method to increase the thickness per unit length.