Skip to main content
SpringerLink
Log in

Shielding effect and emission condition of a screw dislocation near a blunt crack in elliptical inhomogeneity

  • Published:
Meccanica Aims and scope Submit manuscript

Abstract

The shielding effect and emission condition of a screw dislocation near a blunt crack in elastic elliptical inhomogeneity is dealt with. Utilizing the Muskhelishvili complex variable method, the explicit series form solutions of the complex potentials in the matrix and the inclusion regions are derived. The stress intensity factor and critical stress intensity factor for dislocation emission are also calculated. The influences of the orientation of the dislocation and morphology of the blunt crack as well as the material elastic dissimilarity upon the shielding effect and emission criterion are discussed in detail. As a result, numerical analysis and discussion show that the positive screw dislocation can reduce the stress intensity factor of the crack tip (shielding effect) only when it is located in the certain region. The shielding effect increases with the increase of the shear modulus of the matrix and the curvature radius of the blunt crack tip, but decreases with the increase of dislocation azimuth angle. The critical loads at infinity for dislocation emission increases with the increment of the emission angle and the curvature radius of the blunt crack tip, and the most probable angle for screw dislocation emission is zero. The present solutions contain previous results as the special cases.

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

Access this article

Log in via an institution

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

Instant access to the full article PDF.

Institutional subscriptions

Similar content being viewed by others

References

  1. Shiue ST, Lee S (1988) The elastic interaction between screw dislocations and cracks emanating from an elliptic hole. J Appl Phys 64:129–139

    ADS  Google Scholar 

  2. Wang SD, Lee S (1990) An analysis of the elastic interaction between an edge dislocation and an internal crack. Mater Sci Eng A 130:1–10

    Article  MathSciNet  Google Scholar 

  3. Shiue ST, Lee S (1991) Elastic interaction between screw dislocations and collinear edge and internal cracks. Eng Fract Mech 39:591–602

    Article  Google Scholar 

  4. Shiue ST, Lee S (1991) Elastic interaction between screw dislocations and the internal crack near a free surface. Int J Fract 49:29–40

    Article  Google Scholar 

  5. Shiue ST, Zhang TY, Lee S (1993) An edge dislocation near a macrocrack with a microcrack. J Appl Phys 74:6079–6087

    ADS  Google Scholar 

  6. Zhang TY, Lee S (1993) Stress intensity factors of interfacial cracks. Eng Fract Mech 44:539–544

    Article  ADS  Google Scholar 

  7. Shiue ST, Zhang TY, Lee S (1995) Elastic analysis of an edge dislocation and two collinear cracks of different length. Int J Fract 68:333–350

    Article  Google Scholar 

  8. Lin IH, Thomson R (1986) Cleavage dislocation emission, and shielding for cracks under general loading. Acta Metall 34:187

    Article  Google Scholar 

  9. Rice JR, Thomson R (1974) Ductile versus brittle behaviour of crystals. Philos Mag 29:73

    Article  ADS  Google Scholar 

  10. Ohr SM, Chang SJ, Thomson R (1985) Elastic interaction of a wedge crack with a screw dislocation. J Appl Phys 57:1839

    Article  ADS  Google Scholar 

  11. Wang TC (1995) Dislocation nucleation and emission from crack tip. Int J Fract 69:295

    Article  ADS  Google Scholar 

  12. Lung CW, Wang L (1984) Image force on the dislocation near a finite length crack tip. Philos Mag 50:91

    Google Scholar 

  13. Lee S (1987) The image force on the screw dislocation around crack of finite size. Eng Fract Mech 27:539

    Article  Google Scholar 

  14. Huang MX, Li ZH (2004) Dislocation emission criterion from a blunt crack tip. J Mech Phys Solids 52:1991

    Article  MATH  ADS  Google Scholar 

  15. Wu LZ (2000) A crack in a confocal elliptic piezoelectric inhomogeneity embedded in an infinite piezoelectric medium. Int J Fract 104:1–14

    Article  Google Scholar 

  16. Zhang TY, Qian CF (1996) Interaction of a screw dislocation with a thin-film covered mode III crack. Acta Mater 44(11):4513–4520

    Article  Google Scholar 

  17. Fang QH, Liu YW, Jiang CP (2005) Interaction between a screw dislocation and an elliptical elastic inhomogeneity with interfacial cracks. Acta Mech Sin 21:151–159

    Article  ADS  Google Scholar 

  18. Li TL, Li ZH, Sun J (2006) The shielding effects of a screw dislocation near an elliptical blunted crack tip. Scripta Mater 55:703–706

    Article  Google Scholar 

  19. Creager M, Pairs PC (1967) Elastic field equations for blunt cracks with reference to stress corrosion cracking. Int J Fract 3:247

    Article  Google Scholar 

Download references

Author information

Authors and Affiliations

  1. College of Mechanics and Aerospace, Hunan University, Changsha, 410082, P.R. China

    Y. W. Liu, H. P. Song, Q. H. Fang & B. Jin

Authors
  1. Y. W. Liu
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. H. P. Song
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Q. H. Fang
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. B. Jin
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Y. W. Liu.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Liu, Y.W., Song, H.P., Fang, Q.H. et al. Shielding effect and emission condition of a screw dislocation near a blunt crack in elliptical inhomogeneity. Meccanica 45, 519–530 (2010). https://doi.org/10.1007/s11012-009-9271-6

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s11012-009-9271-6

Search

Navigation