The crack tip displacement vector approach to mixed-mode fracture
A method for assessing the ductile failure of thin structures containing arbitrarily oriented cracks is presented. The crack tip displacement vector {delta}{sub {nu}} is used as fracture parameter. Experiments carried out on 4- to 6-mm-thick steel StE 550 and aluminum alloy A12024-T3 sheets with various mixed-mode specimens demonstrate that {delta}{sub {nu}} is more appropriate to characterize ductile mixed Mode I/2 crack initiation and stable crack growth than the J-integral. The Mode I crack resistance curves of standardized C(T)-type specimens give a conservative estimate of crack initiation and resistance to stable growth in the range of near Mode II loading to pure Mode I loading. The {delta}{sub {nu}}-parameter of a cracked component is evaluated with Engineering Treatment Model (ETM). The analytical ETM method requires only the stress intensity factor and plastic limit load solutions of the considered structure as well as the material stress and strain power law as input parameters. Close agreement of ETM predictions to the experimental load versus {delta}{sub {nu}} relationships or load-displacement curves can be achieved, if the proper limit load solution of the cracked structure is available.
- Research Organization:
- German Aerospace Center DLR, Cologne (DE)
- OSTI ID:
- 20000272
- Report Number(s):
- CONF-9805206-; ISBN 0-8031-2602-6
- Resource Relation:
- Conference: Mixed-Mode Crack Behavior, Atlanta, GA (US), 05/06/1998--05/07/1998; Other Information: PBD: 1999; Related Information: In: Mixed-mode crack behavior. ASTM special technical publication 1325, by Miller, K.J.; McDowell, D.L. [eds.], 342 pages.
- Country of Publication:
- United States
- Language:
- English
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