Stable crack growth under mixed mode conditions

Conference · Sun Dec 31 04:00:00 EST 1995

OSTI ID:175388

Bose, K; Ponte-Castaneda, P ^[1]

---

1. Lab de Mechanique de Solids, Palasieau (France)

The problem of interfacial crack growth under mixed-mode conditions is studied. The crack is assumed to be propagating steadily and quasi-statically along the interface between generally dissimilar elastoplastic materials. An analysis is carried out to determine the most singular term in an asymptotic expansion of the stress and deformation fields close to the propagating crack tip. In general, two such asymptotic solutions are found for a given combination of material properties. These two solutions are of the {open_quotes}tensile{close_quotes} and {open_quotes}shear{close_quotes} type, respectively, depending on the dominating stress mode in the line ahead of the crack tip. Thus, the asymptotic analysis predicts discrete and determinate values of the near-tip mode-mix parameter. The asymptotic predictions are compared against results from full-field finite element analysis under small scale yielding and mixed-mode conditions for the special case of crack growth along a brittle/ductile interface. The latter results validate the asymptotic predictions, and also give estimates of the regions of validity of the asymptotic solutions. Based on the above results, a ductile mechanism is proposed to explain the dependence of interfacial toughness on mode-mix. The results, which are in qualitative agreement with available experimental data, show strong dependence on the ductility parameter of the material. It is concluded that ductility provides the main operating mechanism for explaining the dependence of interfacial toughness on the mode-mix of the applied loading, during steady crack growth.

• OSTI ID: 175388
• Report Number(s): CONF-950686--
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
99 GENERAL AND MISCELLANEOUS
ASYMPTOTIC SOLUTIONS
COMPOSITE MATERIALS
CRACK PROPAGATION
DEFORMATION
DUCTILITY
SHEAR