Prediction of Elastic-Plastic Boundary Around Cold-Expanded Holes Using Elastic Strain Measurement

Nripendu Dutta, Jahangir Rasty

Research output: Contribution to journalArticlepeer-review


The cold-expansion process is used routinely for improving the fatigue life of holes in a variety of components. The expansion process involves drawing a slightly oversized tapered mandrel through the hole. Upon expansion, the material near the hole deforms plastically while material away from the hole undergoes elastic deformation. Upon removal of the mandrel, the ensuing elastic recovery of the surrounding material results in the development of a compressive residual stress field around the hole. Since the magnitude of plastic deformation sustained by the material near the hole depends on the severity of the expansion, the elastic-plastic boundary radius (EPBR) during the expansion process can be used to characterize the extent of cold expansion. The elastic-plastic boundary is an important parameter in characterizing the residual stress distribution around cold-expanded holes, as well as in determining required spacing between successively expanded holes. This paper presents a new
Original languageEnglish
Pages (from-to)031009 (6 pages)
JournalASME Journal of Engineering Materials and Technology
StatePublished - Jun 17 2010


Dive into the research topics of 'Prediction of Elastic-Plastic Boundary Around Cold-Expanded Holes Using Elastic Strain Measurement'. Together they form a unique fingerprint.

Cite this