Delamination mechanism maps for a strong elastic coating on an elastic-plastic substrate subjected to contact loading

S. M. Xia, Y. F. Gao, A. F. Bower, L. C. Lev, Y. T. Cheng

Research output: Contribution to journalArticlepeer-review

64 Scopus citations

Abstract

Hard wear resistant coatings that are subjected to contact loading sometimes fail because the coating delaminates from the substrate. In this report, systematic finite element computations are used to model coating delamination under contact loading. The coating and substrate are idealized as elastic and elastic-plastic solids, respectively. The interface between coating and substrate is represented using a cohesive zone law, which can be characterized by its strength and fracture toughness. The system is loaded by an axisymmetric, frictionless spherical indenter. We observe two failure modes: shear cracks may nucleate just outside the contact area if the indentation depth or load exceeds a critical value; in addition, tensile cracks may nucleate at the center of the contact when the indenter is subsequently removed from the surface. Delamination mechanism maps are constructed which show the critical indentation depth and force required to initiate both shear and tensile cracks, as functions of relevant material properties. The fictitious viscosity technique for avoiding convergence problems in finite element simulations of crack nucleation and growth on cohesive interfaces allows us to explore a wider parametric space that a conventional cohesive model cannot handle. Numerical results have also been compared to analytical analyses of asymptotic limits using plate bending and membrane stretching theories, thus providing guidelines for interpreting the simulation results.

Original languageEnglish
Pages (from-to)3685-3699
Number of pages15
JournalInternational Journal of Solids and Structures
Volume44
Issue number11-12
DOIs
StatePublished - Jun 1 2007

Bibliographical note

Funding Information:
This work was performed at the GM/Brown University Collaborative Research Laboratory on Computational Materials Research based at Brown University. S.M.X., Y.F.G., and A.F.B. acknowledge support from General Motors. Y.F.G. also acknowledges the support from the Division of Materials Sciences and Engineering, Office of Basic Energy Sciences, U.S. Department of Energy, under contract DE-AC05-00OR22725 with UT-Battelle, LLC.

Keywords

  • Coating
  • Cohesive model
  • Delamination
  • Fracture mechanics

ASJC Scopus subject areas

  • Modeling and Simulation
  • General Materials Science
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering
  • Applied Mathematics

Fingerprint

Dive into the research topics of 'Delamination mechanism maps for a strong elastic coating on an elastic-plastic substrate subjected to contact loading'. Together they form a unique fingerprint.

Cite this