TY - JOUR
T1 - Failure of bimaterial interfaces
AU - Varias, A. G.
AU - O'Dowd, N. P.
AU - Asaro, R. J.
AU - Shih, C. F.
PY - 1990/6/15
Y1 - 1990/6/15
N2 - The failure of bimaterial interfaces with periodic arrays of cracks or flaws is examined. An adhesive relation is prescribed for the interface which governs the normal and shear stress vs. normal and shear displacement response. These relations provide what amounts to a constitutive law for a thin interface layer which is envisaged to undergo a rupture process when subjected to combined tensile and shear forces. On the basis of these models, we examine the effect of geometry and interfacial properties on the fields of propagating cracks and flaws as well as on the ductility, toughness and failure modes of bimaterial interfaces. Both crystal plasticity and J2 flow theory are used to model the plastic deformation of the materials on either side of the interface. In both descriptions, full account is taken of finite changes in geometry, large plastic strains and material strain rate sensitivity. Within the context of our adhesive models the interface properties are essentially described by three parameters, namely the interface strength σmax, the interface normal separation δc beyond which all adhesion is lost and the work φ{symbol}0 of pure tensile de-adhesion; these three are related through relations of the form φ{symbol}0 = Aσmaxδc, where A depends on the particular functional form of the adhesive relations. Our results, performed for metals with only modest rate sensitivities, demonstrate the pivotal role that the value of the interface strength has in establishing the mechanisms of interface failure and, thereby, the toughness and ductility of the microstructures containing the interface. In addition, the effects of crack and flaw size on the stress-strain fields, and failure modes, that develop at flawed interfaces are studied in a series of calculations involving flaw sizes in the range 15 ≤ α0/δc ≤ 1500.
AB - The failure of bimaterial interfaces with periodic arrays of cracks or flaws is examined. An adhesive relation is prescribed for the interface which governs the normal and shear stress vs. normal and shear displacement response. These relations provide what amounts to a constitutive law for a thin interface layer which is envisaged to undergo a rupture process when subjected to combined tensile and shear forces. On the basis of these models, we examine the effect of geometry and interfacial properties on the fields of propagating cracks and flaws as well as on the ductility, toughness and failure modes of bimaterial interfaces. Both crystal plasticity and J2 flow theory are used to model the plastic deformation of the materials on either side of the interface. In both descriptions, full account is taken of finite changes in geometry, large plastic strains and material strain rate sensitivity. Within the context of our adhesive models the interface properties are essentially described by three parameters, namely the interface strength σmax, the interface normal separation δc beyond which all adhesion is lost and the work φ{symbol}0 of pure tensile de-adhesion; these three are related through relations of the form φ{symbol}0 = Aσmaxδc, where A depends on the particular functional form of the adhesive relations. Our results, performed for metals with only modest rate sensitivities, demonstrate the pivotal role that the value of the interface strength has in establishing the mechanisms of interface failure and, thereby, the toughness and ductility of the microstructures containing the interface. In addition, the effects of crack and flaw size on the stress-strain fields, and failure modes, that develop at flawed interfaces are studied in a series of calculations involving flaw sizes in the range 15 ≤ α0/δc ≤ 1500.
UR - http://www.scopus.com/inward/record.url?scp=0025446470&partnerID=8YFLogxK
U2 - 10.1016/0921-5093(90)90114-I
DO - 10.1016/0921-5093(90)90114-I
M3 - Article
AN - SCOPUS:0025446470
SN - 0921-5093
VL - 126
SP - 65
EP - 93
JO - Materials Science and Engineering: A
JF - Materials Science and Engineering: A
IS - 1-2
ER -