The Problem of Collinear Cracks in a Layered Half-Plane with a Functionally Graded Nonhomogeneous Interfacial Zone

비균질 구배기능 계면영역을 고려한 적층 만무한체의 동일선상 복수균열 해석

  • Jin, Tae-Eun (Power Technology Development Research Center, Korea Power Engineering Corporation) ;
  • Choe, Hyung-Jip (Power Technology Development Research Center, Korea Power Engineering Corporation) ;
  • Lee, Kang-Yong (Dept.of Mechanical Engineering, Yonsei University)
  • 진태은 (한국전력기술(주) 전력기술개발연구소) ;
  • 최형집 (한국전력기술(주) 전력기술개발연구소) ;
  • 이강용 (연세대학교 기계공학과)
  • Published : 1996.04.01


The plane elasticity problem of collinear cracks in a layered medium is investigated. The medium is modeled as bonded structure constituted from a surface layer and a semi-infinite substrate. Along the bond line between the two dissimilar homegeneous constituents, it is assumed that as interfacial zone having the functionally graded, nonhomogeneous elastic modulus exists. The layered medium contains three collinear cracks, one in each constituent material oriented perpendicular to the nominal interfaces. The stiffness matrix formulation is utilized and a set of homogeneous conditions relevant to the given problem is readily satisfied. The proposed mixed boundary value problem is then represented in the form of a system of integral equations with Cauchy-type singular kernels. The stress intensity factors are defined from the crack-tip stress fields possessing the standard square-root singular behavior. The resulting values of stress intensity factors mainly address the interactions among the cracks for various crack sizes and material combinations.


Layered Medium;Collinear Cracks;Functionally Graded nonhomogeneous Interfacial Zone;Stiffness Matrix Formulation;Singular Intergral Equations;Stress Intensity Factors