Establishment of Unified Correlation of In-Plane and Out-of-Plane Constraints with Ductile Fracture Toughness of Steel

Abstract:

In this paper, the finite element method (FEM) based on GTN damage model was used to obtain ductile fracture toughness and investigate the establishment method of unified correlation of in-plane and out-of-plane constraints with ductile fracture toughness of steels. The unified constraint parameter A_p at different equivalent plastic strain (ε_p) isolines has been calculated and analyzed for SEN(B) specimens with a wide range of in-plane and out-of-plane constraints. The results show that the average A_p along the specimen thickness (A_pave) can well characterize a wide range of in-plane and out-of-plane constraints. The suitable ε_p isolines range for establishing the unified correlation between A_pave and ductile fracture toughness of the steel has been obtained. For the specimens with lower constraint, the higher ε_p values should be used. The results also show that the correlation line of J_C/J_ref-A_pave^1/2 is independent of the selections of the suitable ε_p isolines and the reference specimen. This may bring convenience for the establishment and application of the J_C/J_ref -A_pave^1/2correlation lines. Using ductile fracture toughness data of a small number of specimens with different constraints (such as three specimens with different a/W) together with FEM calculations of the parameter A_p, the correlation line of J_C/J_ref-A_pave^1/2can be established. The correlation line may be used in structural integrity assessments incorporating both in-plane and out-of-plane constraints.

• Periodical: Applied Mechanics and Materials (Volume 853)
• Pages: 22-27
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.853.22
• Online since: September 2016
• Authors: Bo Rui Yan, G.Z. Wang*, Fu Zhen Xuan, Shan Tung Tu
• Keywords: Ductile Fracture Toughness, Equivalent Plastic Strain, Finite Element Method, In-Plane Constraint, Out-of-Plane Constraint, Unified Correlation

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