Contemporary analyses in assessing residual stress topographic images enclosing a cold expanded hole

Ozdemir A. T., Toktas I.

CANADIAN METALLURGICAL QUARTERLY, vol.47, no.1, pp.59-70, 2008 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 47 Issue: 1
  • Publication Date: 2008
  • Doi Number: 10.1179/cmq.2008.47.1.59
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.59-70
  • Gazi University Affiliated: Yes


Cold expansion of holes is a complex process; therefore, it is of prime importance to assess the three-dimensional nature of residual stresses surrounding a cold expanded hole. In the present work; the method of step drilling and a novel Fourier series solution were abridged to construct the through thickness residual hoop stress pattern available for any orientation around the hole. Secondly and based on the properties of the experimental data, Artificial Neural Network (ANN) modelling was employed to develop and then train the simulation of complete stress pattern encircling the bore. Results of the experimental technique and ANN prediction were collated by the use of statistical error analyzing methods where mean error percentages were remarkably small for training and testing indicating that these two entirely different approaches were in agreement. At a specific orientation at the bore, some results of the step drilling-Fourier series solution, diffraction methods and ANN modelling were in conformity and similitude was valid only for sections through the thickness at which stress gradient was not changing erratically.