Predicting the fracture strength of ceramic materials using the theory of critical distances

This paper describes a critical distance theory which uses local stress field information to predict the effect of stress concentrations. The approach was originally developed for predicting fatigue limits in metallic materials; this paper shows that it is also capable of predicting fracture strength in ceramics containing notches, long cracks and short cracks. The method is very easy to use, especially in conjunction with finite element analysis. It is proposed that it be given the name the theory of critical distances (TCD). It is a continuum mechanics approach, similar to linear elastic fracture mechanics (LEFM), but of more general applicability.

[1]  B. Lawn.  Fracture of Brittle Solids by Brian Lawn , 1993 .

[2]  G. Pluvinage,et al.  NOTCH EFFECTS IN FATIGUE AND FRACTURE , 2001 .

[3]  K. Tanaka,et al.  Engineering formulae for fatigue strength reduction due to crack-like notches , 1983 .

[4]  E. M. Morozov.  Local Fracture Criterion for Notched Structures , 2001 .

[5]  D. Munz,et al.  Fatigue of Notched Alumina Specimens , 1996 .

[6]  Hoshide Toshihiko,et al.  Simulation of anomalous behavior of a small flaw in strength of engineering ceramics , 1991 .

[7]  Kotoji Ando,et al.  PROCESS ZONE SIZE FAILURE CRITERION AND PROBABILISTIC FRACTURE ASSESSMENT CURVES FOR CERAMICS , 1992 .

[8]  David Taylor,et al.  Prediction of fatigue failure location on a component using a critical distance method , 2000 .

[9]  Strength predictions for notched alumina specimens , 1998 .

[10]  S. Usami,et al.  Strength of ceramic materials containing small flaws , 1986 .

[11]  Yiu-Wing Mai,et al.  Crack Stability and Toughness Characteristics in Brittle Materials , 1986 .

[12]  H. Neuber,et al.  Theorie der technischen Formzahl , 1936 .

[13]  T. Hoshide,et al.  Effect of specimen geometry on strength in engineering ceramics , 1998 .

[14]  Wang,et al.  The validation of some methods of notch fatigue analysis , 2000 .

[15]  Ando,et al.  An investigation into the location of crack initiation sites in alumina, polycarbonate and mild steel , 1999 .

[16]  David Taylor,et al.  Some new methods for predicting fatigue in welded joints , 2002 .

[17]  David Taylor,et al.  Geometrical effects in fatigue: a unifying theoretical model , 1999 .

[18]  S. Usami,et al.  Flaw size dependence in fracture stress of glass and polycrystalline ceramics. , 1985 .

[19]  R. Ritchie,et al.  The effect of microstructure on fracture toughness and fatigue crack growth behavior in γ-titanium aluminide based intermetallics , 1999 .

[20]  Paul C. Paris,et al.  Elastic field equations for blunt cracks with reference to stress corrosion cracking , 1967 .

[21]  Fenghui Wang,et al.  Notch strength of ceramics and statistical analysis , 1995 .