A continuum damage mechanics criterion for mixed mode ductile fracture

1993 ◽  
Vol 63 (3) ◽  
pp. R47-R50 ◽  
Author(s):  
Tie-Jun Wang
Keyword(s):  
Ductile Fracture ◽  
Mixed Mode ◽  
Damage Mechanics ◽  
Continuum Damage Mechanics ◽  
Continuum Damage

Crack Propagation in Mixed-Mode Ductile Fracture with Continuum Damage Mechanics

1989 ◽  
Vol 203 (3) ◽  
pp. 189-199 ◽  
Author(s):  
C L Chow ◽  
J Wang
Keyword(s):  
Crack Initiation ◽  
Crack Propagation ◽  
Ductile Fracture ◽  
Crack Growth ◽  
Mixed Mode ◽  
Damage Mechanics ◽  
Continuum Damage Mechanics ◽  
Propagation Model ◽  
Element Formulation ◽  
Continuum Damage

This paper presents a crack propagation model based on an anisotropic theory of continuum damage mechanics proposed earlier by the authors capable of characterizing sub-critical crack growth in mixed-mode ductile fracture. The embedded β angles of mixed-mode specimens include 75, 60, 45 and 30 degrees. The crack growth criteria chosen are essentially those developed for crack initiation and are postulated as: 1. A crack propagates in the direction of maximum effective damage equivalent stress αd. 2. The threshold condition of crack initiation is satisfied when the overall damage w in an element ahead of the crack tip at the prospective crack growth direction reaches its critical value, wc. The crack growth behaviours of the mixed-mode specimens are analysed using a finite element formulation of the non-proportional loading based on the anisotropic model, and the predicted and measured results are found to be satisfactory. The proposed model is also adapted to predict the critical loads of unstable crack propagation and the results are compared favourably with those determined experimentally. Hence the application of the above two fracture criteria can be made to address the entire history of crack development from initiation to rapid growth.

Characterization of Notched Ductile Failure With Continuum Damage Mechanics

1990 ◽  
Vol 112 (4) ◽  
pp. 412-421 ◽  
Author(s):  
C. L. Chow ◽  
K. Y. Sze
Keyword(s):  
Ductile Fracture ◽  
Circular Hole ◽  
Damage Mechanics ◽  
Damage Model ◽  
Ductile Failure ◽  
Continuum Damage Mechanics ◽  
Thin Plates ◽  
Continuum Damage ◽  
Anisotropic Model ◽  
Aluminum Alloy 2024

A recently developed anisotropic model of continuum damage mechanics has been applied successfully to characterize ductile fracture of cracked plates under mode I and mixed mode failures. The damage model is further extended in this investigation to examine its applicability to include notch ductile fracture of thin plates containing a circular hole. Two hole sizes of 16 mm and 24 mm diameters are chosen and the specimen material is aluminum alloy 2024-T3. Fracture loads of the plates are predicted by the damage model and compared satisfactorily with those determined experimentally. This investigation provides an important confirmation that not only the anisotropic model of continuum damage mechanics but also the same failure criterion developed can be effectively employed to characterize both ductile fracture for plates containing an isolated macro-crack or circular hole which would otherwise not be possible using the conventional theory of fracture mechanics. The successful development of the unified approach to characterize ductile failure provides a vital impetus for design engineers in the general application of the theory of continuum damage mechanics to solve practical engineering problems.

Sign in / Sign up

Export Citation Format

Share Document