Effects of tool deflection in accumulated double-sided incremental forming regarding part geometry

Huaqing Ren, Newell Moser, Zixuan Zhang, Kornel F. Ehmann, Jian Cao*

*Corresponding author for this work

Research output: Chapter in Book/Report/Conference proceedingConference contribution

1 Scopus citations

Abstract

Incremental forming is a flexible dieless forming process. In incremental forming, the metal sheet is clamped around its periphery. One or multiple generic stylus-type tools move along a predefined toolpath, incrementally deforming the sheet metal into a final, freeform shape. Compared with the traditional sheet metal forming process, the incremental forming process is more flexible, energy efficient and cost effective due to lower capital investment related to tooling. However, maintaining tight geometric tolerances in incremental formed parts can be a challenge. Specifically, undesired global bending is usually induced near the region between the tools and fixture resulting in a compromise in geometric accuracy. To address this issue, Accumulated Double-Sided Incremental Forming (ADSIF) is proposed, which utilizes two tools on both sides of the metal to better achieve localized deformation while simultaneously constraining global bending outside the forming area. Moreover, in ADSIF, the two tools are moving from inward to outward, and thus the tools are always forming virgin material and so as to limit forces on the alreadyformed part. Thus, ADSIF has a higher potential to achieve the desired geometry. Nevertheless, tool deflection due to machine compliance is still an issue that can have a considerable effect on geometric accuracy. In this work, the effect of tool deflection related to part geometry is studied for the ADSIF process. The nature of using two tools, rather than one, in ADSIF inherently implies that relative tool position is a critical process parameter. It is the region near these two tools where local squeezing and bending of the sheet occurs, the primary modes of deformation found in ADSIF. The change of relative tool positions (i.e., tool gap and relative position angle) are studied in detail by first developing an analytical model. It is concluded that the tool gap will be enlarged under the influence of tool compliance while the relative position angle is less affected. Additionally, a finite element simulation capable of modeling tool deflection is established. The comparison between the simulation results using rigid tools and deformable ones clearly demonstrated the significant influence of tool compliance on part geometry. Lastly, an axisymmetric part with varying wall angles was formed, and it was confirmed that ADSIF demonstrates improved geometry accuracy compared with conventional Double-Sided Incremental Forming.

Original languageEnglish (US)
Title of host publicationProcessing
PublisherAmerican Society of Mechanical Engineers
ISBN (Electronic)9780791849897
DOIs
StatePublished - Jan 1 2016
EventASME 2016 11th International Manufacturing Science and Engineering Conference, MSEC 2016 - Blacksburg, United States
Duration: Jun 27 2016Jul 1 2016

Publication series

NameASME 2016 11th International Manufacturing Science and Engineering Conference, MSEC 2016
Volume1

Other

OtherASME 2016 11th International Manufacturing Science and Engineering Conference, MSEC 2016
CountryUnited States
CityBlacksburg
Period6/27/167/1/16

ASJC Scopus subject areas

  • Industrial and Manufacturing Engineering

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    Ren, H., Moser, N., Zhang, Z., Ehmann, K. F., & Cao, J. (2016). Effects of tool deflection in accumulated double-sided incremental forming regarding part geometry. In Processing (ASME 2016 11th International Manufacturing Science and Engineering Conference, MSEC 2016; Vol. 1). American Society of Mechanical Engineers. https://doi.org/10.1115/MSEC20168839