Skip to main content
Log in

Evaluation of crack tip fields and stress intensity factors in functionally graded elastic materials: Cracks parallel to elastic gradient

  • Published:
International Journal of Fracture Aims and scope Submit manuscript

Abstract

Particulate functionally graded materials (FGM) made of glass-filled epoxy with edge cracks parallel to the direction of the elastic gradient and subjected to pure bending have been studied. Crack tip measurements are used to examine continuum models for FGMs by treating the material as isotropic and nonhomogeneous at macroscales. Situations where cracks are located on the compliant and the stiff sides of the beams are separately examined by mapping crack tip deformations using optical interferometry. Comparative experiments on homogeneous compositions corresponding to identical elastic properties of the crack tip region in the FGM are also undertaken. A methodology for extracting fracture parameters in FGMs based on locally homogeneous material descriptions is advanced. Companion finite element models are used to aid the development of fringe analysis procedures and to provide a direct comparison to the optical measurements. Stress intensity factors in FGMs are compared to each other and to their homogeneous counterparts. Optical measurements near quasi-statically growing cracks in FGMs have been undertaken, and crack growth resistance behavior is explained using crack initiation toughness variation as a function of filler volume fraction in homogeneous sheets.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Similar content being viewed by others

References

  • Bao, G. and Cai, H. (1997). Delamination cracking in functionally graded coating/metal substrate systems. Acta Materialia 45, 1055–1066.

    Google Scholar 

  • Butcher, R.J., Rousseau, C.-E. and Tippur, H.V. (1999). A functionally graded particulate composite: preparation, measurements and failure analysis. Acta Materialia 47, 259–268.

    Google Scholar 

  • Delale, F. and Erdogan, F. (1983). The crack problem for a nonhomogeneous plane. ASME Journal of Applied Mechanics 50, 609–614.

    Google Scholar 

  • Eischen, J.W. (1987). Fracture of nonhomogeneous materials. International Journal of Fracture 34, 3–22.

    Google Scholar 

  • Erdogan, F. (1995). Fracture mechanics of functionally graded materials. Composites Engineering 5, 753–770.

    Google Scholar 

  • Giannakopoulos, A.E. and Suresh, S. (1997). Indentation of solids with gradients in elastic properties: Part I. Point force. International Journal of Solids Structures 34, 2357–2392.

    Google Scholar 

  • Honein, T. and Herrmann, G. (1997). Conservation laws in nonhomogeneous plane elastostatics. Journal of the Mechanics and Physics of Solids 45, 789–805.

    Google Scholar 

  • Huet, C. (19 ). Application of variational concepts to size effects in elastic heterogeneous bodies. Journal of the Mechanics and Physics of Solids 38, 813–841.

    Google Scholar 

  • Jin, Z.-H. and Batra, R.C. (1996). Some basic fracture mechanics concepts in functionally graded materials. Journal of the Mechanics and Physics of Solids 44, 1221–1235.

    Google Scholar 

  • Jin, Z.-H. and Noda, N. (1994). Crack-tip singular fields in nonhomogeneous materials. ASME Journal of Applied Mechanics 61, 738–740.

    Google Scholar 

  • Krishnaswamy, S., Rosakis, A.J. and Rarichandran, G. (1991). On the extent of dominance of asymptotic,elastodynamic crack-tip fields: Part II. Numerical investigation of three-dimensional and transient effects. ASME Journal of Applied Mechanics 58, 95–103.

    Google Scholar 

  • Lee, Y.-D. and Erdogan, F. (1995). Residual/thermal stresses in FGM and laminated thermal barrier coatings. International Journal of Fracture 69, 145–165.

    Google Scholar 

  • Marur, P.R. and Tippur, H.V. (1998). Evaluation of mechanical properties of functionally graded materials. Journal of Testing and Evaluation 26, 539–545.

    Google Scholar 

  • Marur, P.R. and Tippur, H.V. (2000). Dynamic response of bimaterial and graded interface cracks under impact loading. International Journal of Fracture 103, 103–109.

    Google Scholar 

  • Moloney, A.C., Kausch, H.H., Kaiser, T. and Beer, H.R. (1987). Parameters determining the strength and toughness of particulate filled epoxide resins. Journal of Materials Science 22, 381–393.

    Google Scholar 

  • Ostoja-Starzewski, M., Jasiuk, I., Wang, W. and Alzebdeh, K. Composites with functionalled graded interphases: Mesocontinuum concept and effective tansverse conductivity. Acta Materialia 44, 2057–2066. 2057 066.

    Google Scholar 

  • Parameswaran, V. and Shukla, A. (2000). Processing and characterization of a model functionally gradient material. Journal of Materials Science 35, 21–29.

    Google Scholar 

  • Rice, J.R. (1968). A path of independent integral and the approximate analysis of strain concentration by notches and cracks. ASME Journal of Applied Mechanics 35, 379–386.

    Google Scholar 

  • Rosakis, A.J. and Ravi-Chandar, K. (1986). On crack-tip stress state: An experimental evaluation of threedimensional effects. International Journal of Solids and Structures 22, 121–138.

    Google Scholar 

  • Rousseau, C.-E. (2000). Evaluation of crack tip fields and fracture parameters in functionally graded materials. Ph.D. Dissertation, Auburn University.

  • Rousseau, C.-E. and Tippur, H.V. (2000). Compositionally graded materials with cracks normal to the elastic gradient. Acta Materialia 48, 4021–4033.

    Google Scholar 

  • Rousseau, C.-E. and Tippur, H.V. (2001). Dynamic fracture of compositionally graded materials with cracks along the elastic gradient: Experiments and analysis. Mechanics of Materials 33, pp. 403–421.

    Google Scholar 

  • Sinha, J.K., Tippur, H.V. and Xu, L. (1997). An interferometric and finite element investigation of interfacial crack tip fields: Role of mode-mixity on 3-D stress variations. International Journal of Solids and Structures 34, 741-754.

    Google Scholar 

  • Tippur, H.V., Krishnaswamy, S. and Rosakis, A.J. (1991). A coherent gradient sensor for crack tip deformation measurements: Analysis and experimental results. International Journal of Fracture 48, 193-204.

    Google Scholar 

  • Weng, G.J. (1984). Some elastic properties of reinforced solids, with special reference to isotropic ones containing spherical inclusions. International Journal of Engineering Sciences 22, 845–856.

    Google Scholar 

  • Whitney, J.M., Daniel, I.M. and Pipes, R.B. (1984). Experimental Mechanics of Fiber Reinforced Composite Materials, SEM Monograph No. 4, Prentice Hall, Inc., NJ.

    Google Scholar 

  • Williams, M.L. (1957). On the stress distribution at the base of a stationary crack. ASME Journal of Applied Mechanics 24, 109–114.

    Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to H.V. Tippur.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Rousseau, CE., Tippur, H. Evaluation of crack tip fields and stress intensity factors in functionally graded elastic materials: Cracks parallel to elastic gradient. International Journal of Fracture 114, 87–112 (2002). https://doi.org/10.1023/A:1014889628080

Download citation

  • Issue Date:

  • DOI: https://doi.org/10.1023/A:1014889628080

Navigation