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

Paper Number: 61656

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

61656 - Application of 3D Constraint-Based Fracture Mechanics for the Determination of R-Curves of Thermal Aged 16MND5 Steel 

In the current work, the comprehensive combined effects of thermal aging, and 3D in-plane and out-of-plane constraints on the fracture resistance curves (J-R and CTOD-R) of reactor pressure vessel (RPV) steel, 16MND5 were investigated.  First, the fracture experiments of RPV steel with different thermal aging durations using variously sized clamped single edge notched tension (SENT) specimens, were summarized.  Then, three-dimensional finite element method (FEM) was used to determine the constraint parameters for the test specimens.  From the analysis results, it was shown that the normalized T₁₁, and the independent portion of T₃₃ can accurately quantify the in-plane and out-of-plane constraint levels, respectively.  Next, the in-plane and out-of-plane constraint-quantified R-curves were developed.  Results showed that the effects of thermal aging, in-plane and out of-plane constraints on fracture toughness present significant interactions.  The specific characteristics observed are: the influence of constraints on fracture toughness decreases with the increase of thermal aging duration, especially the in-plane constraint effect; the effect of thermal aging on fracture behavior is more significant under low constraint conditions.  Further, the current in-plane and out-of-plane constraint dependent R-curves can easily reproduce all tested R-curves determined by clamped SENT specimens.  It was also shown that they can accurately predict R-curves of new tested pin-loaded SENT specimens or real RPV cracked structures under different thermal aging durations.

Presenting Author: Xin Wang Carleton University

Authors:

Zheng Liu Tianjin University
Xin Wang Carleton University
Ron Miller Carleton University
Yueyin Shen Nuclear Power Institute of China
Xu Chen Tianjin University