Correlation between von Mises strain and material thinning in a hydroformed sample of Ti35A aerospace grade titanium

Colin Bell, Ellen Jump, William Kerr, Jonathan Corney, Nicola Zuelli, David Savings

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

2 Citations (Scopus)
42 Downloads (Pure)


This paper presents the results of an experimental investigation of the strain measured on a sample of Ti35A (commercially pure) titanium that was formed past the point of failure in a hydroforming operation. The sample was etched prior to forming to allow for a strain map of the exterior to be created and examined by using a circle grid analysis (CGA) technique. The sample was scanned post forming with precise optical inspection to ascertain an accurate model of its geometry. This paper discusses the results of the analyses including the full geometric and surface strain measurements. This paper then compares material thinning properties to strain values and finds a linear relationship of approximately 3:1 between Von Mises strain and material thinning percentage throughout the sample. The slope of the line appears to correlate strongly with the material's Poisson's ratio and could have potential uses in process planning.

Original languageEnglish
Title of host publicationProceedings of the 20th International ESAFORM Conference on Material Forming, ESAFORM 2017
EditorsDermot Brabazon, Sumsun Naher, Inam Ul Ahad
Place of Publication[Melville, New York]
Number of pages6
Publication statusPublished - 16 Oct 2017
Event20th International ESAFORM Conference on Material Forming, ESAFORM 2017 - Dublin, Ireland
Duration: 26 Apr 201728 Apr 2017

Publication series

NameAIP Conference Proceedings
PublisherAIP Publishing
ISSN (Print)0094-243X


Conference20th International ESAFORM Conference on Material Forming, ESAFORM 2017


  • titanium
  • hydroforming
  • surface strain measurements

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