Fracture Toughness for Ductile Materials Under Low Constraint Conditions

المؤلفون

  • Osama A. Terfas Department of Marine and Offshore Engineering, University of Tripoli
  • Reda B. Areibi Department of Mechanical and Industrial Engineering, University of Tripoli
  • Abdulbaset M. Kraima Department of Mechanical and Industrial Engineering, University of Zawia

الكلمات المفتاحية:

fracture toughness، Crack tip stress، fracture resistance، tearing modulus

الملخص

The crack tip stress field for low constraint conditions arising from short cracked bars, thin cracked bars, and across the thickness of the bar itself is examined. The reduction of crack tip stresses is correlated with the fracture resistance. The material failure curve that correlates the critical fracture toughness with the mean stress is constructed. It is observed that testing deeply thin geometries would provide similar fracture resistance to that measured on shallow cracked thick geometries. Fracture toughness data obtained from finite elements analysis were consistent with the experimental fracture data. The ductile fracture resistance defined as tearing modulus (TR=∂J/E∂a) reveals that fracture data obtained from different cracked geometries have similar effect on crack tip constraint. This investigation emphasised that fracture toughness is strongly influenced by the level of stress. The finding of this research of low constrained geometries is essential in structural integrity assessment as it quantifies precisely the stress condition and the fracture toughness, inherently avoiding the unnecessary replacement.

المراجع

ASTM E1737, 1998. Standard test method for J-integral characterization of fracture toughness, American Society for Testing and Materials.

BS7448, 1997. Method for determination of fracture resistance curves and initiation values for stable crack extension in metallic materials, British Standard Institution, London.

Zhu, X-K. 2015. Advances in Fracture Toughness Test Methods for Ductile Materials in Low Constraint Conditions, 14th International Conference on Pressure Vessel Technology, Shanghai, China.

Han, J.J., Larrosa, N. O., Ainsworth R. A., Kim Y. J. 2016. The use of SE(T) specimen fracture toughness forFFS assessment of defects in low constraint conditions, 21st Euorpean Conference on Fracture, Italy.

Kim,Y., Chao, Y. J., Zhu, X. K. 2003. Effect of specimen size and crack depth on 3D crack-front constraint for SENB specimens. International Journal of Solids and structures.

Kim,Y-Jae., Kim, J. S., Cho, S. M., Kim, Y-Jin. 2004. 3-D constraint effects on J testing and crack tip constraint in M(T), SE(B),SE(T) and C(T) specimens: numerical study. Engineering Fracture Mechanics.

Hancock, J.W., Reuter, W.G., Parks, D.M. 1993. Constraint and toughness parameterised by T. Constrainteffect in fracture. ASTM STP 1171, Philadelphia.

Ostby, E., Thaulow, C., Zhang, Z. L. 2007. Numerical simulations of specimen size and mismatch effects in ductile crack growth-Part I: Tearing resistance and crack growth paths. Engineering Fracture Mechanics.

Zhu, X-K., Joyce, J. A. 2007. J–Resistance curve testing of HY80 steel using SE(B) specimens and normalization method, Engineering Fracture Mechanics.

Smith, D. J., Swankie, T. D., Pavier, M. J., Smith M. C. 2008. The effect of specimen dimensions on mixed mode ductile fracture, Engineering Fracture Mechanics.

التنزيلات

منشور

2023-02-19