Incremental Sheet Forming (ISF) is a freeform manufacturing method whereby a 3D geometry is created by progressively deforming a metal sheet with a single point tool following a defined trajectory. The thickness distribution of a formed part is a major consideration of the process and is believed to be improved by forming the geometry in multiple stages. This paper describes a series of experiments in which truncated cone geometries were formed using two multistage methods and compared to the same geometry formed using the traditional single stage method. The geometric accuracy and thickness distributions, including 3D thickness distribution plots, of each are examined using digital image correlation (DIC). The data collected indicate that multistage forming, compared to single stage forming, has a significant effect on the geometric accuracy of the processed sheets. Moreover, the results of the experiments conducted in this paper show that sheets processed with multistage forming do not have a uniform sheet thickness reduction, rather they have a parabolic-like thickness distribution in the processed region.

Meeting Name

47th SME North American Manufacturing Research Conference, NAMRC 2019 (2019: Jun. 10-14, Erie, PA)


Mechanical and Aerospace Engineering

Research Center/Lab(s)

Intelligent Systems Center


This work was supported by the Boeing Company and the Center for Aerospace Manufacturing Technologies at the Missouri University of Science and Technology.

Keywords and Phrases

Digital Image Correlation; Geometric Accuracy; Incremental Sheet Forming; Multistage; Strain; Thickness

International Standard Serial Number (ISSN)


Document Type

Article - Conference proceedings

Document Version

Final Version

File Type





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Creative Commons Licensing

Creative Commons License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 License.

Publication Date

01 Jun 2019