Ghosal, AK and Narasimhan, R (1997) An approximate analysis of notch-tip deformation under mixed-mode loading in ductile solids. In: Transactions of the ASME: Journal of Applied Mechanics, 64 (3). pp. 695-696.Full text not available from this repository. (Request a copy)
In practical situations, the loading experienced at the tip of a crack or notch in a structural component could be very complex resulting in mixed-mode fracture. In recent years, several investigators (Tohgo et al., 1988; Aoki et al., 1990; Maccagno and Knott, 1992; Ghosal and Narasimhan, 1994) have studied mixed-mode ductile fracture initiation (involving modes I and II) using experimental and computational methods. Ghosal and Narasimhan (1994) concluded, based on numerical simulations which modeled the micromechanics of ductile fracture, that the notch-tip deformation length (see definition given below) at fracture initiation is reasonably independent of mode-mixity (except for loadings very close to Mode II). This contention is supported by the experimental results for the notch-tip displacements at fracture initiation presented by Tohgo et al. (1988) for a structural steel SM41A. Thus, the notch-tip deformation length may be viewed as a local fracture characterizing parameter under mixed-mode loading in ductile solids. However, an analytical expression connecting this quantity with the J-integral is not available in the literature. Such an expression can facilitate interpretation of experimentally measured notch-tip displacements under mixed-mode loading. Further, since at present there is no method for determining the near-tip plastic mode-mixity, experimental results (see, for example, Tohgo'et al., 1988) are being reported using the ratio of the elastic stress intensity factors (KI/KII). This may be meaningless because large plastic yielding can take place prior to fracture initiation in low strength alloys. It is proposed here that a measurement of the notch-tip opening and sliding displacements (as in Tohgo et al. (1988) and Maccagno and Knott (1992)) can be used to deduce the near-tip plastic mode-mixity.
|Item Type:||Journal Article|
|Additional Information:||Copyright of this article belongs to ASME.|
|Department/Centre:||Division of Mechanical Sciences > Mechanical Engineering|
|Date Deposited:||21 May 2007|
|Last Modified:||27 Aug 2008 12:39|
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