Three dimensional analysis of periodic cracking in FGM coatings under thermal stresses

DAĞ S., Yildirin B., Erdogan F.

9th International Conference on Multiscale and Functionally Graded Materials, Hawaii, United States Of America, 15 - 18 October 2006, vol.973, pp.676-677, (Full Text) identifier

  • Publication Type: Conference Paper / Full Text
  • Volume: 973
  • City: Hawaii
  • Country: United States Of America
  • Page Numbers: pp.676-677
  • Keywords: FGM coatings, periodic cracks, semi-elliptical surface crack, stress intensity factor, INTENSITY FACTORS
  • Middle East Technical University Affiliated: Yes

Abstract

A three dimensional finite element method is used to examine periodic surface cracking problem in a functionally graded coating subjected to transient thermal loads. The ceramic/metal FGM coating is assumed to contain periodic semi-elliptical cracks and to be perfectly bonded to a homogeneous substrate. The composite structure is subjected to transient residual/thermal stresses. Temperature and displacement fields are computed using a three dimensional finite element approach. Finite element models are created by considering a unit cell in the periodic structure. Mode I stress intensity factors are evaluated by means of the displacement correlation technique (DCT). Presented results illustrate the influence of crack periodicity on the transient behavior of the stress intensity factors.