Thickness dependence of cracking resistance in thin aluminium plates
(1999) Journal of the Mechanics and Physics of Solids — Vol. 47, n° 10, p. 2093-2123 (1999)
Files
pdfdocument.pdf
Restricted Access - Adobe PDF
- 506.59 KB
Details
- Authors
Delannay, Francis 
- Abstract
- The influence of thickness on the fracture toughness of aluminium 6082T0 thin plates of 1-6 mm thicknesses was investigated experimentally and numerically from tensile testing of cracked DENT specimens. The critical J-integral, J(c), critical CTOD, delta(CTODc), and essential work of fracture, w(e), are found to increase with thickness and to constitute equivalent measures of fracture toughness at small thickness. For larger thickness, J(c) and delta(CTODc) increase non-linearly with thickness and reach a maximum for 5-6 mm thickness Whereas iv, keeps increasing linearly with thickness. This difference is related to a more progressive development of the necking zone in front of the crack tip when thickness increases: at large thickness, cracking initiates well before the neck has developed to its stationary value during propagation, w(e) is more directly related to the steady-state crack growth resistance. A linear regression on the fracture toughness/thickness curve allows further separation of the two contributions of the essential work of fracture: the necking work and the fracture work spent for damaging. The maximum of the stress triaxiality ratio is shown to constitute a pertinent parameter for characterising how constraint affects cracking initiation in the present context where out-of-plane constraint dominates in-plane constraint. It allows justifying the shape of the J(c)/thickness relationship and results in the proposal of a 3D J(c)/thickness/triaxiality fracture locus. As fracture profiles are macroscopically flat with microscopic dimples and with only very small shear lips along the edges, a local criterion based on the growth and coalescence of voids has been used in order to predict fracture initiation. (C) 1999 Elsevier Science Ltd. All rights reserved.
- Affiliations
Citations
Pardoen, T., Marchal, Y., & Delannay, F. (1999). Thickness dependence of cracking resistance in thin aluminium plates. Journal of the Mechanics and Physics of Solids, 47(10), 2093-2123. https://doi.org/10.1016/S0022-5096(99)00011-3 (Original work published 1999)