ISSN: 1546-962X
Page Count: 12

On the quantification of the constraint effect along a three-dimensional crack front
Wang, Xin
Associate Professor, Department of Mechanical and Aerospace Engineering, Carleton University, Ontario

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: JAI101550
DOI: 10.1520/JAI101550
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