Session: MF-01-01 Application of Fracture Mechanics in Failure Assessment I

Paper Number: 62656

Start Time: Wednesday, July 14, 2021, 09:00 AM

62656 - Three-Dimensional Finite Element Analyses of Separation Work Rate For Crack Extension in a Thin Curved Compact Tension Specimen With Finite Step Nodal Release Method 

Separation work rate as a function of the crack extension in a thin compact tension (CT) specimen of Zr-2.5Nb pressure tube material is obtained by a three-dimensional finite element analysis with the nodal release method.  The straight crack front for the crack extension is assumed.  The crack extension is simulated by releasing the nodal points ahead of the initial straight fatigue crack front in the CT specimen.  The crack extension follows the available experimental crack extension data based on the electric potential drop method for a given applied displacement.  The computational results show the evolution of the plastic zone sizes and shapes.  With the nodal release method for the straight crack extension, the separation work rate as a function of the crack extension is similar to the experimental J-R curve and therefore the use of the experimental J-R curve for the selection of the cohesive energy as a function of the crack extension is appropriate for the CT specimens.  The computational results suggest that when a straight crack front is implied in a two-dimensional finite element analysis of crack extension with the cohesive energy approach, the increase of the cohesive energy is needed for the increase of the crack extension in order to match with the experimental results.

Presenting Author: Shengjia Wu University of Michigan

Authors:

Shin-Jang Sung University of Michigan
Shengjia Wu University of Michigan
Jwo Pan University of Michigan