STP1508: On the Quantification of the Constraint Effect Along a Three-Dimensional Crack Front

    Wang, Xin
    Associate Professor, Carleton University, Ottawa, Ontario

    Pages: 16    Published: Jan 2009


    Abstract

    In this paper we examined the characterization of constraint effects for surface cracked plates under uniaxial and biaxial tension loadings. First, three-dimensional (3D) modified boundary layer analyses were conducted using the finite element method to study the constraint effect at a typical 3D crack front. The analyses were carried out using small geometry change formulation and deformation plasticity material model. Elastic-plastic crack front stress fields at a constant J and various T-stress levels were obtained. Three-dimensional elastic-plastic analyses were performed for semi-circular surface cracks in a finite thickness plate, under remote uniaxial and biaxial tension loading conditions. In topological planes perpendicular to the crack fronts, the crack stress fields were obtained. Then, J-Q and J-T two-parameter approaches are used in characterizing the elastic-plastic crack-tip stress fields along the 3D crack front. It is found that the J-Q characterization provides good estimate for the constraint effect for crack-tip stress fields. Reasonable agreements are achieved between the T-stress based Q-factors and the Q-factors obtained from finite element analysis.

    Keywords:

    elastic-plastic fracture mechanics, constraint effects, T, -stress, Q, -factors, surface cracked plate, biaxial loading


    Paper ID: STP48762S

    Committee/Subcommittee: E08.08

    DOI: 10.1520/STP48762S


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