Reactor Pressure Vessel Fracture Analysis Capabilities in Grizzly

Spencer, Benjamin¹  Backman, Marie²  Chakraborty, Pritam¹  Hoffman, William³ 

[1] Idaho National Lab. (INL), Idaho Falls, ID (United States);Univ. of Tennessee, Knoxville, TN (United States);Univ. of Idaho, Moscow, ID (United States)

关键词: Fracture Mechanics;    Mixed Mode;    Reactor Pressure Vessel;    Stress Intensity Factor;   

DOI  :  10.2172/1235198
RP-ID  :  INL/EXT--15-34736
PID  :  OSTI ID: 1235198

美国|英语

来源: SciTech Connect

【 摘 要 】

Efforts have been underway to develop fracture mechanics capabilities in the Grizzly code to enable it to be used to perform deterministic fracture assessments of degraded reactor pressure vessels (RPVs). Development in prior years has resulted a capability to calculate -integrals. For this application, these are used to calculate stress intensity factors for cracks to be used in deterministic linear elastic fracture mechanics (LEFM) assessments of fracture in degraded RPVs. The -integral can only be used to evaluate stress intensity factors for axis-aligned flaws because it can only be used to obtain the stress intensity factor for pure Mode I loading. Off-axis flaws will be subjected to mixed-mode loading. For this reason, work has continued to expand the set of fracture mechanics capabilities to permit it to evaluate off-axis flaws. This report documents the following work to enhance Grizzly???s engineering fracture mechanics capabilities for RPVs: ??? Interaction Integral and -stress: To obtain mixed-mode stress intensity factors, a capability to evaluate interaction integrals for 2D or 3D flaws has been developed. A -stress evaluation capability has been developed to evaluate the constraint at crack tips in 2D or 3D. Initial verification testing of these capabilities is documented here. ??? Benchmarking for axis-aligned flaws: Grizzly???s capabilities to evaluate stress intensity factors for axis-aligned flaws have been benchmarked against calculations for the same conditions in FAVOR. ??? Off-axis flaw demonstration: The newly-developed interaction integral capabilities are demon- strated in an application to calculate the mixed-mode stress intensity factors for off-axis flaws. ??? Other code enhancements: Other enhancements to the thermomechanics capabilities that relate to the solution of the engineering RPV fracture problem are documented here.