Applied Mathematics and Mechanics

, Volume 14, Issue 9, pp 817–828

# The analyses of the three-dimensional stress structure near the crack tip of mode I CT specimens in elastic-plastic state (II)—The analyses of the stress structure

• Yue Zhu-feng
• Zheng Chang-qing
Article

## Abstract

Based on [1], the stress structures of the smooth region and shear lip of the specimens have been investigated in the paper. The characteristics of the stress structure in the smooth region have been found that the variable z can separated out; the stresses in the midsection can be obtained by the plane strain FEM results or HRR structure modified by the stress triaxiality. The effects of load level and thickness on the stress structure can be reflected by the distribution of CTOD along the thickness direction. The obtained expressions of the stresses are very simple and visualized. The analyses of the stress structure in the shear lip show that the stresses can be obtained by different methods of interpolation to a certain precise degree.

A new degree parameter of the plane strain state has been put forward and studied. The parameter can reflect relatively well the variation of the kind and thickness of the specimen as well as the load level. The fracture parameter has also been investigated to be sure that it can be obtained by modified CTOD with the stress triaxiality.

## Key words

stress structure singularity Z1 region stress triaxialityRσ CTOD shear lip interpolative method degree parameter of the plane strain state

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