skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Process Development And Simulation For Cold Fabrication Of Doubly Curved Metal Plate By Using Line Array Roll Set

Abstract

For effective manufacturing of a doubly curved sheet metal, a novel sheet metal forming process is proposed. The suggested process uses a Line Array Roll Set (LARS) composed of a pair of upper and lower roll assemblies in a symmetric manner. The process offers flexibility as compared with the conventional manufacturing processes, because it does not require any complex-shaped die and loss of material by blank-holding is minimized. LARS allows flexibility of the incremental forming process and adopts the principle of bending deformation, resulting in a slight deformation in thickness. Rolls composed of line array roll sets are divided into a driving roll row and two idle roll rows. The arrayed rolls in the central lines of the upper and lower roll assemblies are motor-driven so that they deform and transfer the sheet metal using friction between the rolls and the sheet metal. The remaining rolls are idle rolls, generating bending deformation with driving rolls. Furthermore, all the rolls are movable in any direction so that they are adaptable to any size or shape of the desired three-dimensional configuration. In the process, the sheet is deformed incrementally as deformation proceeds simultaneously in rolling and transverse directions step by step. Consequently,more » it can be applied to the fabrication of doubly curved ship hull plates by undergoing several passes. In this work, FEM simulations are carried out for verification of the proposed incremental forming system using the chosen design parameters. Based on the results of the simulation, the relationship between the roll set configuration and the curvature of a sheet metal is determined. The process information such as the forming loads and torques acting on every roll is analyzed as important data for the design and development of the manufacturing system.« less

Authors:
; ; ;  [1]; ;  [2]
  1. KAIST, Dept. of Mechanical Eng., Science Town, Daejeon, 305-701 (Korea, Republic of)
  2. DSME - Daewoo Shipbuilding and Marine Engineering Co., LTD, Aju-dong, Geoje-si, Gyeongsangnam-do, 656-714 (Korea, Republic of)
Publication Date:
OSTI Identifier:
21061770
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 908; Journal Issue: 1; Conference: NUMIFORM 2007: 9. international conference on numerical methods in industrial forming processes, Porto (Portugal), 17-21 Jun 2007; Other Information: DOI: 10.1063/1.2740919; (c) 2007 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ALLOYS; BENDING; COMPUTERIZED SIMULATION; FINITE ELEMENT METHOD; FLEXIBILITY; FRICTION; MANUFACTURING; METALS; PLATES; ROLLING; SHEETS; THREE-DIMENSIONAL CALCULATIONS; TORQUE

Citation Formats

Shim, D. S., Jung, C. G., Seong, D. Y., Yang, D. Y., Han, J. M., and Han, M. S. Process Development And Simulation For Cold Fabrication Of Doubly Curved Metal Plate By Using Line Array Roll Set. United States: N. p., 2007. Web. doi:10.1063/1.2740919.
Shim, D. S., Jung, C. G., Seong, D. Y., Yang, D. Y., Han, J. M., & Han, M. S. Process Development And Simulation For Cold Fabrication Of Doubly Curved Metal Plate By Using Line Array Roll Set. United States. doi:10.1063/1.2740919.
Shim, D. S., Jung, C. G., Seong, D. Y., Yang, D. Y., Han, J. M., and Han, M. S. Thu . "Process Development And Simulation For Cold Fabrication Of Doubly Curved Metal Plate By Using Line Array Roll Set". United States. doi:10.1063/1.2740919.
@article{osti_21061770,
title = {Process Development And Simulation For Cold Fabrication Of Doubly Curved Metal Plate By Using Line Array Roll Set},
author = {Shim, D. S. and Jung, C. G. and Seong, D. Y. and Yang, D. Y. and Han, J. M. and Han, M. S.},
abstractNote = {For effective manufacturing of a doubly curved sheet metal, a novel sheet metal forming process is proposed. The suggested process uses a Line Array Roll Set (LARS) composed of a pair of upper and lower roll assemblies in a symmetric manner. The process offers flexibility as compared with the conventional manufacturing processes, because it does not require any complex-shaped die and loss of material by blank-holding is minimized. LARS allows flexibility of the incremental forming process and adopts the principle of bending deformation, resulting in a slight deformation in thickness. Rolls composed of line array roll sets are divided into a driving roll row and two idle roll rows. The arrayed rolls in the central lines of the upper and lower roll assemblies are motor-driven so that they deform and transfer the sheet metal using friction between the rolls and the sheet metal. The remaining rolls are idle rolls, generating bending deformation with driving rolls. Furthermore, all the rolls are movable in any direction so that they are adaptable to any size or shape of the desired three-dimensional configuration. In the process, the sheet is deformed incrementally as deformation proceeds simultaneously in rolling and transverse directions step by step. Consequently, it can be applied to the fabrication of doubly curved ship hull plates by undergoing several passes. In this work, FEM simulations are carried out for verification of the proposed incremental forming system using the chosen design parameters. Based on the results of the simulation, the relationship between the roll set configuration and the curvature of a sheet metal is determined. The process information such as the forming loads and torques acting on every roll is analyzed as important data for the design and development of the manufacturing system.},
doi = {10.1063/1.2740919},
journal = {AIP Conference Proceedings},
number = 1,
volume = 908,
place = {United States},
year = {Thu May 17 00:00:00 EDT 2007},
month = {Thu May 17 00:00:00 EDT 2007}
}
  • Doubly curved thick plate forming in shipbuilding industries is currently performed by a thermal forming process, called as Line Heating by using gas flame torches. Due to the empirical manual work of it, the industries are eager for an alternative way to manufacture curved thick plates for ships. It was envisaged in this study to manufacture doubly curved thick plates by the multi-punch die forming. Experiments and finite element analyses were conducted to evaluate the feasibility of the reconfigurable discrete die forming to the thick plates. Single and segmented multiple step forming procedures were considered from both forming efficiency andmore » accuracy. Configuration of the multi-punch dies suitable for the segmented multiple step forming was also explored. As a result, Segmented multiple step forming with matched dies had a limited formability when the objective shapes become complicate, while a unmatched die configuration provided better possibility to manufacture large curved plates for ships.« less
  • This paper provides a theoretical approach in predicting the penetration of elastic-elastoplastic deformation of a bend plate at the top roll contact when a continuous four-roll plate bending process is operating. The theory enables the prediction of the plate local bend radius relative to its corresponding anticipated bend radius, and the depth of elastic-elastoplastic deformation penetration to be obtained. The analysis considers a possibly elastic deformation being sandwiched by two elastoplastic bands, and separates the elastoplastic yielding into the instantaneously incremental elastic and the instantaneously incremental plastic deformation. It accounts for the operational mechanisms in bending of an initially flatmore » plate in single/first pass, and of an initially curved plate in second/subsequent pass.« less
  • We analyze the deformation induced by focusing a CW high power laser beam on stainless steel plate. A non-linear 3D finite element approach is used to simulate the thermo-elastoplastic deformation, the heat conduction, and stresses. Material properties including density, yield stress, Young modulus, specific heat, and thermal expansion coefficient are considered as temperature-dependent. The effect of heating time on transient temperatures, stresses, strains and bending angles during the process is studied, and the process parameters affecting the bending angles were also investigated.
  • A novel steel for cold work roll was developed in this work. Its phase structures were determined by X-ray diffraction, and phase transformation temperatures during the cooling process were measured by Differential Scanning Calorimeter. The Fe–C isopleths of the steel were calculated by Thermo-Calc to preliminarily determine the characteristic temperatures of the different phases. Then the specimens were quenched at these characteristic temperatures. The typical microstructures were observed by Optical Microscopy and Field Emission Scanning Electron Microscopy with Energy Disperse Spectroscopy. The results show that α-Fe, MC, M{sub 2}C and M{sub 7}C{sub 3} precipitate when the specimen is cooled slowlymore » to room temperature. According to the DSC curve and the Fe–C isopleths, the characteristic temperatures of the phase transformation and carbide precipitation are chosen as 1380 °C, 1240 °C, 1200 °C and 1150 °C respectively. Primary austenite precipitates at 1380 °C, then eutectic reaction occurs in residual liquid after quenching and the eutectic microstructures distribute along the crystal grain boundary. The eutectic MC is leaf-like and eutectic M{sub 2}C is fibrous-like. Both of them precipitate in ternary eutectic reaction simultaneously at 1240 °C, grow together in the form of dendrite along the crystal grain boundary. Secondary MC precipitates from the austenitic matrix at 1200 °C and nucleates at the position where eutectic MC located accompanied by the dissolving of eutectic carbides. The mixed secondary M{sub 2}C and M{sub 7}C{sub 3} precipitate at 1150 °C. The secondary M{sub 2}C is strip-like and honeycomb-like, while the M{sub 7}C{sub 3} is chrysanthemum-like and maze-like. - Highlights: • The solidification process was analyzed by Thermo-Calc, DSC, XRD and SEM observation. • Primary and secondary carbides precipitated during solidification were determined. • The three dimensional morphologies of all carbides was observed. • The eutectic MC exhibits the dendritical structure which was not observed before.« less
  • The engineering design, fabrication, assembly, operation, economic analysis, and process support research and development for an Experimental Process System Development Unit for producing semiconductor-grade silicon using the silane-to-silicon process are reported. The design activity was completed. About 95% of purchased equipment was received. The draft of the operations manual was about 50% complete and the design of the free-space system continued. The system using silicon power transfer, melting, and shotting on a psuedocontinuous basis was demonstrated.