Effect of Plastic Strain on Elastic-Plastic Fracture Toughness of SM490 Carbon Steel (Assessment by Stress-Based Criterion for Ductile Crack Initiation)

DOI Web Site 1 Citations 15 References

Bibliographic Information

Other Title
  • SM490鋼の弾塑性破壊じん性に及ぼす塑性ひずみの影響（応力破壊基準による検討）
  • SM490コウ ノ ダン ソセイ ハカイジンセイ ニ オヨボス ソセイヒズミ ノ エイキョウ(オウリョク ハカイ キジュン ニ ヨル ケントウ)

Search this article

Description

Although the plastic strain induced in materials increases the mechanical strength, it may reduce the fracture toughness. In this study, the change in fracture toughness of SM490 carbon steel due to pre-straining was investigated using a stress-based criterion for ductile crack initiation. The specimens with blunt notch of various radiuses were used in addition to those with conventional fatigue pre-cracking. The degree of applied plastic strain was 5%, 10% or 20%. The fracture toughness was largest when the induced plastic strain was 5%, although it decreased for the plastic strains of 10% and 20%. The stress and strain distributions near the crack tip of fracture toughness test specimens was investigated by elastic-plastic finite element analyses using a well-correlated stress-strain curve for large strain. It was shown that the critical condition at the onset of the ductile crack was better correlated with the equivalent stress than the plastic strain at the crack tip. By using the stress-based criterion, which was represented by the equivalent stress and stress triaxiality, the change in the fracture toughness due to pre-straining could be reasonably explained. Based on these results, it was concluded that the stress-based criterion should be used for predicting the ductile crack initiation.

Journal

Citations (1)*help

See more

References(15)*help

See more

Keywords

Details 詳細情報について

Report a problem

Back to top